Ubuntu Manpage: podman-run - Run a command in a new container

Provided by: podman_4.9.3+ds1-1ubuntu0.2_amd64

NAME

       podman-run - Run a command in a new container

SYNOPSIS

       podman run [options] image [command [arg ...]]

       podman container run [options] image [command [arg ...]]

DESCRIPTION

Run a process in a new container. podman run starts a process with its own file system, its own
networking, and its own isolated process tree. The image which starts the process may define defaults
related to the process that will be run in the container, the networking to expose, and more, but podman
run gives final control to the operator or administrator who starts the container from the image. For
that reason podman run has more options than any other Podman command.

If the image is not already loaded then podman run will pull the image, and all image dependencies, from
the repository in the same way running podman pull image , before it starts the container from that
image.

Several files will be automatically created within the container. These include /etc/hosts,
/etc/hostname, and /etc/resolv.conf to manage networking. These will be based on the host's version of
the files, though they can be customized with options (for example, --dns will override the host's DNS
servers in the created resolv.conf). Additionally, a container environment file is created in each
container to indicate to programs they are running in a container. This file is located at
/run/.containerenv (or /var/run/.containerenv for FreeBSD containers). When using the --privileged flag
the .containerenv contains name/value pairs indicating the container engine version, whether the engine
is running in rootless mode, the container name and ID, as well as the image name and ID that the
container is based on. Note: /run/.containerenv will not be created when a volume is mounted on /run.

When running from a user defined network namespace, the /etc/netns/NSNAME/resolv.conf will be used if it
exists, otherwise /etc/resolv.conf will be used.

Default settings are defined in containers.conf. Most settings for remote connections use the servers
containers.conf, except when documented in man pages.

IMAGE

The image is specified using transport:path format. If no transport is specified, the docker (container
registry) transport is used by default. For remote Podman, including Mac and Windows (excluding WSL2)
machines, docker is the only allowed transport.

dir:path
An existing local directory path storing the manifest, layer tarballs and signatures as individual
files. This is a non-standardized format, primarily useful for debugging or noninvasive container
inspection.

$ podman save --format docker-dir fedora -o /tmp/fedora
$ podman run dir:/tmp/fedora echo hello

docker://docker-reference (Default)
An image reference stored in a remote container image registry. Example:
"quay.io/podman/stable:latest". The reference can include a path to a specific registry; if it does not,
the registries listed in registries.conf are queried to find a matching image. By default, credentials
from podman login (stored at $XDG_RUNTIME_DIR/containers/auth.json by default) are used to authenticate;
otherwise it falls back to using credentials in $HOME/.docker/config.json.

$ podman run registry.fedoraproject.org/fedora:latest echo hello

docker-archive:path[:docker-reference] An image stored in the docker save formatted file. docker-
reference is only used when creating such a file, and it must not contain a digest.

$ podman save --format docker-archive fedora -o /tmp/fedora
$ podman run docker-archive:/tmp/fedora echo hello

docker-daemon:docker-reference
An image in docker-reference format stored in the docker daemon internal storage. The docker-reference
can also be an image ID (docker-daemon:algo:digest).

$ sudo docker pull fedora
$ sudo podman run docker-daemon:docker.io/library/fedora echo hello

oci-archive:path:tag
An image in a directory compliant with the "Open Container Image Layout Specification" at the specified
path and specified with a tag.

$ podman save --format oci-archive fedora -o /tmp/fedora
$ podman run oci-archive:/tmp/fedora echo hello

OPTIONS

--add-host=host:ip
Add a custom host-to-IP mapping (host:ip)

Add a line to /etc/hosts. The format is hostname:ip. The --add-host option can be set multiple times.
Conflicts with the --no-hosts option.

--annotation=key=value
Add an annotation to the container. This option can be set multiple times.

--arch=ARCH
Override the architecture, defaults to hosts, of the image to be pulled. For example, arm. Unless
overridden, subsequent lookups of the same image in the local storage matches this architecture,
regardless of the host.

--attach, -a=stdin | stdout | stderr
Attach to STDIN, STDOUT or STDERR.

In foreground mode (the default when -d is not specified), podman run can start the process in the
container and attach the console to the process's standard input, output, and error. It can even pretend
to be a TTY (this is what most command-line executables expect) and pass along signals. The -a option can
be set for each of stdin, stdout, and stderr.

--authfile=path
Path of the authentication file. Default is ${XDG_RUNTIME_DIR}/containers/auth.json on Linux, and
$HOME/.config/containers/auth.json on Windows/macOS. The file is created by podman login. If the
authorization state is not found there, $HOME/.docker/config.json is checked, which is set using docker
login.

Note: There is also the option to override the default path of the authentication file by setting the
REGISTRY_AUTH_FILE environment variable. This can be done with export REGISTRY_AUTH_FILE=path.

--blkio-weight=weight
Block IO relative weight. The weight is a value between 10 and 1000.

This option is not supported on cgroups V1 rootless systems.

--blkio-weight-device=device:weight
Block IO relative device weight.

--cap-add=capability
Add Linux capabilities.

--cap-drop=capability
Drop Linux capabilities.

--cgroup-conf=KEY=VALUE
When running on cgroup v2, specify the cgroup file to write to and its value. For example --cgroup-
conf=memory.high=1073741824 sets the memory.high limit to 1GB.

--cgroup-parent=path
Path to cgroups under which the cgroup for the container is created. If the path is not absolute, the
path is considered to be relative to the cgroups path of the init process. Cgroups are created if they do
not already exist.

--cgroupns=mode
Set the cgroup namespace mode for the container.

• host: use the host's cgroup namespace inside the container.

• container:id: join the namespace of the specified container.

• private: create a new cgroup namespace.

• ns:path: join the namespace at the specified path.

If the host uses cgroups v1, the default is set to host. On cgroups v2, the default is private.

--cgroups=how
Determines whether the container creates CGroups.

Default is enabled.

The enabled option creates a new cgroup under the cgroup-parent. The disabled option forces the
container to not create CGroups, and thus conflicts with CGroup options (--cgroupns and --cgroup-parent).
The no-conmon option disables a new CGroup only for the conmon process. The split option splits the
current CGroup in two sub-cgroups: one for conmon and one for the container payload. It is not possible
to set --cgroup-parent with split.

--chrootdirs=path
Path to a directory inside the container that is treated as a chroot directory. Any Podman managed file
(e.g., /etc/resolv.conf, /etc/hosts, etc/hostname) that is mounted into the root directory is mounted
into that location as well. Multiple directories are separated with a comma.

--cidfile=file
Write the container ID to file. The file is removed along with the container, except when used with
podman --remote run on detached containers.

--conmon-pidfile=file
Write the pid of the conmon process to a file. As conmon runs in a separate process than Podman, this is
necessary when using systemd to restart Podman containers. (This option is not available with the remote
Podman client, including Mac and Windows (excluding WSL2) machines)

--cpu-period=limit
Set the CPU period for the Completely Fair Scheduler (CFS), which is a duration in microseconds. Once the
container's CPU quota is used up, it will not be scheduled to run until the current period ends. Defaults
to 100000 microseconds.

On some systems, changing the resource limits may not be allowed for non-root users. For more details,
see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-
resource-limits-fails-with-a-permissions-error

This option is not supported on cgroups V1 rootless systems.

--cpu-quota=limit
Limit the CPU Completely Fair Scheduler (CFS) quota.

Limit the container's CPU usage. By default, containers run with the full CPU resource. The limit is a
number in microseconds. If a number is provided, the container is allowed to use that much CPU time until
the CPU period ends (controllable via --cpu-period).

This option is not supported on cgroups V1 rootless systems.

--cpu-rt-period=microseconds
Limit the CPU real-time period in microseconds.

Limit the container's Real Time CPU usage. This option tells the kernel to restrict the container's Real
Time CPU usage to the period specified.

This option is only supported on cgroups V1 rootful systems.

--cpu-rt-runtime=microseconds
Limit the CPU real-time runtime in microseconds.

Limit the containers Real Time CPU usage. This option tells the kernel to limit the amount of time in a
given CPU period Real Time tasks may consume. Ex: Period of 1,000,000us and Runtime of 950,000us means
that this container can consume 95% of available CPU and leave the remaining 5% to normal priority tasks.

The sum of all runtimes across containers cannot exceed the amount allotted to the parent cgroup.

This option is only supported on cgroups V1 rootful systems.

--cpu-shares, -c=shares
CPU shares (relative weight).

By default, all containers get the same proportion of CPU cycles. This proportion can be modified by
changing the container's CPU share weighting relative to the combined weight of all the running
containers. Default weight is 1024.

The proportion only applies when CPU-intensive processes are running. When tasks in one container are
idle, other containers can use the left-over CPU time. The actual amount of CPU time varies depending on
the number of containers running on the system.

For example, consider three containers, one has a cpu-share of 1024 and two others have a cpu-share
setting of 512. When processes in all three containers attempt to use 100% of CPU, the first container
receives 50% of the total CPU time. If a fourth container is added with a cpu-share of 1024, the first
container only gets 33% of the CPU. The remaining containers receive 16.5%, 16.5% and 33% of the CPU.

On a multi-core system, the shares of CPU time are distributed over all CPU cores. Even if a container is
limited to less than 100% of CPU time, it can use 100% of each individual CPU core.

For example, consider a system with more than three cores. If the container C0 is started with --cpu-
shares=512 running one process, and another container C1 with --cpu-shares=1024 running two processes,
this can result in the following division of CPU shares:

┌─────┬───────────┬─────┬──────────────┐
│ PID │ container │ CPU │ CPU share │
├─────┼───────────┼─────┼──────────────┤
│ 100 │ C0 │ 0 │ 100% of CPU0 │
├─────┼───────────┼─────┼──────────────┤
│ 101 │ C1 │ 1 │ 100% of CPU1 │
├─────┼───────────┼─────┼──────────────┤
│ 102 │ C1 │ 2 │ 100% of CPU2 │
└─────┴───────────┴─────┴──────────────┘

This option is not supported on cgroups V1 rootless systems.

--cpus=number
Number of CPUs. The default is 0.0 which means no limit. This is shorthand for --cpu-period and --cpu-
quota, therefore the option cannot be specified with --cpu-period or --cpu-quota.

On some systems, changing the CPU limits may not be allowed for non-root users. For more details, see
https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error

This option is not supported on cgroups V1 rootless systems.

--cpuset-cpus=number
CPUs in which to allow execution. Can be specified as a comma-separated list (e.g. 0,1), as a range (e.g.
0-3), or any combination thereof (e.g. 0-3,7,11-15).

This option is not supported on cgroups V1 rootless systems.

--cpuset-mems=nodes
Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.

If there are four memory nodes on the system (0-3), use --cpuset-mems=0,1 then processes in the container
only uses memory from the first two memory nodes.

This option is not supported on cgroups V1 rootless systems.

--decryption-key=key[:passphrase]
The [key[:passphrase]] to be used for decryption of images. Key can point to keys and/or certificates.
Decryption is tried with all keys. If the key is protected by a passphrase, it is required to be passed
in the argument and omitted otherwise.

--detach, -d
Detached mode: run the container in the background and print the new container ID. The default is false.

At any time run podman ps in the other shell to view a list of the running containers. Reattach to a
detached container with podman attach command.

When attached via tty mode, detach from the container (and leave it running) using a configurable key
sequence. The default sequence is ctrl-p,ctrl-q. Specify the key sequence using the --detach-keys
option, or configure it in the containers.conf file: see containers.conf(5) for more information.

--detach-keys=sequence
Specify the key sequence for detaching a container. Format is a single character [a-Z] or one or more
ctrl-<value> characters where <value> is one of: a-z, @, ^, [, , or _. Specifying "" disables this
feature. The default is ctrl-p,ctrl-q.

This option can also be set in containers.conf(5) file.

--device=host-device[:container-device][:permissions]
Add a host device to the container. Optional permissions parameter can be used to specify device
permissions by combining r for read, w for write, and m for mknod(2).

Example: --device=/dev/sdc:/dev/xvdc:rwm.

Note: if host-device is a symbolic link then it is resolved first. The container only stores the major
and minor numbers of the host device.

Podman may load kernel modules required for using the specified device. The devices that Podman loads
modules for when necessary are: /dev/fuse.

In rootless mode, the new device is bind mounted in the container from the host rather than Podman
creating it within the container space. Because the bind mount retains its SELinux label on SELinux
systems, the container can get permission denied when accessing the mounted device. Modify SELinux
settings to allow containers to use all device labels via the following command:

$ sudo setsebool -P container_use_devices=true

Note: if the user only has access rights via a group, accessing the device from inside a rootless
container fails. Use the --group-add keep-groups flag to pass the user's supplementary group access into
the container.

--device-cgroup-rule="type major:minor mode"
Add a rule to the cgroup allowed devices list. The rule is expected to be in the format specified in the
Linux kernel documentation (Documentation/cgroup-v1/devices.txt):
- type: a (all), c (char), or b (block);
- major and minor: either a number, or * for all;
- mode: a composition of r (read), w (write), and m (mknod(2)).

--device-read-bps=path:rate
Limit read rate (in bytes per second) from a device (e.g. --device-read-bps=/dev/sda:1mb).

This option is not supported on cgroups V1 rootless systems.

--device-read-iops=path:rate
Limit read rate (in IO operations per second) from a device (e.g. --device-read-iops=/dev/sda:1000).

This option is not supported on cgroups V1 rootless systems.

--device-write-bps=path:rate
Limit write rate (in bytes per second) to a device (e.g. --device-write-bps=/dev/sda:1mb).

This option is not supported on cgroups V1 rootless systems.

--device-write-iops=path:rate
Limit write rate (in IO operations per second) to a device (e.g. --device-write-iops=/dev/sda:1000).

This option is not supported on cgroups V1 rootless systems.

--disable-content-trust
This is a Docker-specific option to disable image verification to a container registry and is not
supported by Podman. This option is a NOOP and provided solely for scripting compatibility.

--dns=ipaddr
Set custom DNS servers.

This option can be used to override the DNS configuration passed to the container. Typically this is
necessary when the host DNS configuration is invalid for the container (e.g., 127.0.0.1). When this is
the case the --dns flag is necessary for every run.

The special value none can be specified to disable creation of /etc/resolv.conf in the container by
Podman. The /etc/resolv.conf file in the image is used without changes.

This option cannot be combined with --network that is set to none or container:id.

--dns-option=option
Set custom DNS options. Invalid if using --dns-option with --network that is set to none or container:id.

--dns-search=domain
Set custom DNS search domains. Invalid if using --dns-search with --network that is set to none or
container:id. Use --dns-search=. to remove the search domain.

--entrypoint="command" | '["command", arg1 , ...]'
Override the default ENTRYPOINT from the image.

The ENTRYPOINT of an image is similar to a COMMAND because it specifies what executable to run when the
container starts, but it is (purposely) more difficult to override. The ENTRYPOINT gives a container its
default nature or behavior. When the ENTRYPOINT is set, the container runs as if it were that binary,
complete with default options. More options can be passed in via the COMMAND. But, if a user wants to run
something else inside the container, the --entrypoint option allows a new ENTRYPOINT to be specified.

Specify multi option commands in the form of a json string.

--env, -e=env
Set environment variables.

This option allows arbitrary environment variables that are available for the process to be launched
inside of the container. If an environment variable is specified without a value, Podman checks the host
environment for a value and set the variable only if it is set on the host. As a special case, if an
environment variable ending in * is specified without a value, Podman searches the host environment for
variables starting with the prefix and adds those variables to the container.

See ⟨#environment⟩ note below for precedence and examples.

--env-file=file
Read in a line-delimited file of environment variables.

See ⟨#environment⟩ note below for precedence and examples.

--env-host
Use host environment inside of the container. See Environment note below for precedence. (This option is
not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines)

--env-merge=env
Preprocess default environment variables for the containers. For example if image contains environment
variable hello=world user can preprocess it using --env-merge hello=${hello}-some so new value is
hello=world-some.

Please note that if the environment variable hello is not present in the image, then it'll be replaced by
an empty string and so using --env-merge hello=${hello}-some would result in the new value of
hello=-some, notice the leading - delimiter.

--expose=port
Expose a port, or a range of ports (e.g. --expose=3300-3310) to set up port redirection on the host
system.

--gidmap=[flags]container_uid:from_uid[:amount]
Run the container in a new user namespace using the supplied GID mapping. This option conflicts with the
--userns and --subgidname options. This option provides a way to map host GIDs to container GIDs in the
same way as --uidmap maps host UIDs to container UIDs. For details see --uidmap.

Note: the --gidmap option cannot be called in conjunction with the --pod option as a gidmap cannot be set
on the container level when in a pod.

--group-add=group | keep-groups
Assign additional groups to the primary user running within the container process.

• keep-groups is a special flag that tells Podman to keep the supplementary group access.

Allows container to use the user's supplementary group access. If file systems or devices are only
accessible by the rootless user's group, this flag tells the OCI runtime to pass the group access into
the container. Currently only available with the crun OCI runtime. Note: keep-groups is exclusive, other
groups cannot be specified with this flag. (Not available for remote commands, including Mac and Windows
(excluding WSL2) machines)

--group-entry=ENTRY
Customize the entry that is written to the /etc/group file within the container when --user is used.

The variables $GROUPNAME, $GID, and $USERLIST are automatically replaced with their value at runtime if
present.

--health-cmd="command" | '["command", arg1 , ...]'
Set or alter a healthcheck command for a container. The command is a command to be executed inside the
container that determines the container health. The command is required for other healthcheck options to
be applied. A value of none disables existing healthchecks.

Multiple options can be passed in the form of a JSON array; otherwise, the command is interpreted as an
argument to /bin/sh -c.

--health-interval=interval
Set an interval for the healthchecks. An interval of disable results in no automatic timer setup. The
default is 30s.

--health-on-failure=action
Action to take once the container transitions to an unhealthy state. The default is none.

• none: Take no action.

• kill: Kill the container.

• restart: Restart the container. Do not combine the restart action with the --restart flag.
When running inside of a systemd unit, consider using the kill or stop action instead to make
use of systemd's restart policy.

• stop: Stop the container.

--health-retries=retries
The number of retries allowed before a healthcheck is considered to be unhealthy. The default value is 3.

--health-start-period=period
The initialization time needed for a container to bootstrap. The value can be expressed in time format
like 2m3s. The default value is 0s.

--health-startup-cmd="command" | '["command", arg1 , ...]'
Set a startup healthcheck command for a container. This command is executed inside the container and is
used to gate the regular healthcheck. When the startup command succeeds, the regular healthcheck begins
and the startup healthcheck ceases. Optionally, if the command fails for a set number of attempts, the
container is restarted. A startup healthcheck can be used to ensure that containers with an extended
startup period are not marked as unhealthy until they are fully started. Startup healthchecks can only be
used when a regular healthcheck (from the container's image or the --health-cmd option) is also set.

--health-startup-interval=interval
Set an interval for the startup healthcheck. An interval of disable results in no automatic timer setup.
The default is 30s.

--health-startup-retries=retries
The number of attempts allowed before the startup healthcheck restarts the container. If set to 0, the
container is never restarted. The default is 0.

--health-startup-success=retries
The number of successful runs required before the startup healthcheck succeeds and the regular
healthcheck begins. A value of 0 means that any success begins the regular healthcheck. The default is 0.

--health-startup-timeout=timeout
The maximum time a startup healthcheck command has to complete before it is marked as failed. The value
can be expressed in a time format like 2m3s. The default value is 30s.

--health-timeout=timeout
The maximum time allowed to complete the healthcheck before an interval is considered failed. Like start-
period, the value can be expressed in a time format such as 1m22s. The default value is 30s.

--help
Print usage statement

--hostname, -h=name
Container host name

Sets the container host name that is available inside the container. Can only be used with a private UTS
namespace --uts=private (default). If --pod is specified and the pod shares the UTS namespace (default)
the pod's hostname is used.

--hostuser=name
Add a user account to /etc/passwd from the host to the container. The Username or UID must exist on the
host system.

--http-proxy
By default proxy environment variables are passed into the container if set for the Podman process. This
can be disabled by setting the value to false. The environment variables passed in include http_proxy,
https_proxy, ftp_proxy, no_proxy, and also the upper case versions of those. This option is only needed
when the host system must use a proxy but the container does not use any proxy. Proxy environment
variables specified for the container in any other way overrides the values that have been passed through
from the host. (Other ways to specify the proxy for the container include passing the values with the
--env flag, or hard coding the proxy environment at container build time.) When used with the remote
client it uses the proxy environment variables that are set on the server process.

Defaults to true.

--image-volume=bind | tmpfs | ignore
Tells Podman how to handle the builtin image volumes. Default is bind.

• bind: An anonymous named volume is created and mounted into the container.

• tmpfs: The volume is mounted onto the container as a tmpfs, which allows the users to create
content that disappears when the container is stopped.

• ignore: All volumes are just ignored and no action is taken.

--init
Run an init inside the container that forwards signals and reaps processes. The container-init binary is
mounted at /run/podman-init. Mounting over /run breaks container execution.

--init-path=path
Path to the container-init binary.

--interactive, -i
When set to true, keep stdin open even if not attached. The default is false.

--ip=ipv4
Specify a static IPv4 address for the container, for example 10.88.64.128. This option can only be used
if the container is joined to only a single network - i.e., --network=network-name is used at most once -
and if the container is not joining another container's network namespace via --network=container:id.
The address must be within the network's IP address pool (default 10.88.0.0/16).

To specify multiple static IP addresses per container, set multiple networks using the --network option
with a static IP address specified for each using the ip mode for that option.

--ip6=ipv6
Specify a static IPv6 address for the container, for example fd46:db93:aa76:ac37::10. This option can
only be used if the container is joined to only a single network - i.e., --network=network-name is used
at most once - and if the container is not joining another container's network namespace via
--network=container:id. The address must be within the network's IPv6 address pool.

To specify multiple static IPv6 addresses per container, set multiple networks using the --network option
with a static IPv6 address specified for each using the ip6 mode for that option.

--ipc=ipc
Set the IPC namespace mode for a container. The default is to create a private IPC namespace.

• "": Use Podman's default, defined in containers.conf.

• container:id: reuses another container's shared memory, semaphores, and message queues

• host: use the host's shared memory, semaphores, and message queues inside the container. Note:
the host mode gives the container full access to local shared memory and is therefore considered
insecure.

• none: private IPC namespace, with /dev/shm not mounted.

• ns:path: path to an IPC namespace to join.

• private: private IPC namespace.

• shareable: private IPC namespace with a possibility to share it with other containers.

--label, -l=key=value
Add metadata to a container.

--label-file=file
Read in a line-delimited file of labels.

--link-local-ip=ip
Not implemented.

--log-driver=driver
Logging driver for the container. Currently available options are k8s-file, journald, none and
passthrough, with json-file aliased to k8s-file for scripting compatibility. (Default journald).

The podman info command below displays the default log-driver for the system.

$ podman info --format '{{ .Host.LogDriver }}'
journald

The passthrough driver passes down the standard streams (stdin, stdout, stderr) to the container. It is
not allowed with the remote Podman client, including Mac and Windows (excluding WSL2) machines, and on a
tty, since it is vulnerable to attacks via TIOCSTI.

--log-opt=name=value
Logging driver specific options.

Set custom logging configuration. The following *name*s are supported:

path: specify a path to the log file
(e.g. --log-opt path=/var/log/container/mycontainer.json);

max-size: specify a max size of the log file
(e.g. --log-opt max-size=10mb);

tag: specify a custom log tag for the container
(e.g. --log-opt tag="{{.ImageName}}". It supports the same keys as podman inspect --format. This
option is currently supported only by the journald log driver.

--mac-address=address
Container network interface MAC address (e.g. 92:d0:c6:0a:29:33) This option can only be used if the
container is joined to only a single network - i.e., --network=network-name is used at most once - and if
the container is not joining another container's network namespace via --network=container:id.

Remember that the MAC address in an Ethernet network must be unique. The IPv6 link-local address is
based on the device's MAC address according to RFC4862.

To specify multiple static MAC addresses per container, set multiple networks using the --network option
with a static MAC address specified for each using the mac mode for that option.

--memory, -m=number[unit]
Memory limit. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes).

Allows the memory available to a container to be constrained. If the host supports swap memory, then the
-m memory setting can be larger than physical RAM. If a limit of 0 is specified (not using -m), the
container's memory is not limited. The actual limit may be rounded up to a multiple of the operating
system's page size (the value is very large, that's millions of trillions).

This option is not supported on cgroups V1 rootless systems.

--memory-reservation=number[unit]
Memory soft limit. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes).

After setting memory reservation, when the system detects memory contention or low memory, containers are
forced to restrict their consumption to their reservation. So always set the value below --memory,
otherwise the hard limit takes precedence. By default, memory reservation is the same as memory limit.

This option is not supported on cgroups V1 rootless systems.

--memory-swap=number[unit]
A limit value equal to memory plus swap. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g
(gibibytes).

Must be used with the -m (--memory) flag. The argument value must be larger than that of
-m (--memory) By default, it is set to double the value of --memory.

Set number to -1 to enable unlimited swap.

This option is not supported on cgroups V1 rootless systems.

--memory-swappiness=number
Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.

This flag is only supported on cgroups V1 rootful systems.

--mount=type=TYPE,TYPE-SPECIFIC-OPTION[,...]
Attach a filesystem mount to the container

Current supported mount TYPEs are bind, devpts, glob, image, ramfs, tmpfs and volume. [1] ⟨#Footnote1⟩

e.g.
type=bind,source=/path/on/host,destination=/path/in/container

type=bind,src=/path/on/host,dst=/path/in/container,relabel=shared

type=bind,src=/path/on/host,dst=/path/in/container,relabel=shared,U=true

type=devpts,destination=/dev/pts

type=glob,src=/usr/lib/libfoo*,destination=/usr/lib,ro=true

type=image,source=fedora,destination=/fedora-image,rw=true

type=ramfs,tmpfs-size=512M,destination=/path/in/container

type=tmpfs,tmpfs-size=512M,destination=/path/in/container

type=tmpfs,destination=/path/in/container,noswap

type=volume,source=vol1,destination=/path/in/container,ro=true

Common Options:

· src, source: mount source spec for bind, glob, and volume. Mandatory for bind and glob.

· dst, destination, target: mount destination spec.

When source globs are specified without the destination directory,
the files and directories are mounted with their complete path
within the container. When the destination is specified, the
files and directories matching the glob on the base file name
on the destination directory are mounted. The option
`type=glob,src=/foo*,destination=/tmp/bar` tells container engines
to mount host files matching /foo* to the /tmp/bar/
directory in the container.

Options specific to volume:

· ro, readonly: true or false (default).

. U, chown: true or false (default). Change recursively the owner and group of the source volume based on the UID and GID of the container.

· idmap: true or false (default). If specified, create an idmapped mount to the target user namespace in the container.
The idmap option supports a custom mapping that can be different than the user namespace used by the container.
The mapping can be specified after the idmap option like: `idmap=uids=0-1-10#10-11-10;gids=0-100-10`. For each triplet, the first value is the
start of the backing file system IDs that are mapped to the second value on the host. The length of this mapping is given in the third value.
Multiple ranges are separated with #. If the specified mapping is prepended with a '@' then the mapping is considered relative to the container
user namespace. The host ID for the mapping is changed to account for the relative position of the container user in the container user namespace.

Options specific to image:

· rw, readwrite: true or false (default).

Options specific to bind and glob:

· ro, readonly: true or false (default).

· bind-propagation: shared, slave, private, unbindable, rshared, rslave, runbindable, or rprivate(default). See also mount(2).

. bind-nonrecursive: do not set up a recursive bind mount. By default it is recursive.

. relabel: shared, private.

· idmap: true or false (default). If specified, create an idmapped mount to the target user namespace in the container.

. U, chown: true or false (default). Change recursively the owner and group of the source volume based on the UID and GID of the container.

Options specific to tmpfs and ramfs:

· ro, readonly: true or false (default).

· tmpfs-size: Size of the tmpfs/ramfs mount in bytes. Unlimited by default in Linux.

· tmpfs-mode: File mode of the tmpfs/ramfs in octal. (e.g. 700 or 0700.) Defaults to 1777 in Linux.

· tmpcopyup: Enable copyup from the image directory at the same location to the tmpfs/ramfs. Used by default.

· notmpcopyup: Disable copying files from the image to the tmpfs/ramfs.

. U, chown: true or false (default). Change recursively the owner and group of the source volume based on the UID and GID of the container.

Options specific to devpts:

· uid: UID of the file owner (default 0).

· gid: GID of the file owner (default 0).

· mode: permission mask for the file (default 600).

· max: maximum number of PTYs (default 1048576).

--name=name
Assign a name to the container.

The operator can identify a container in three ways:

• UUID long identifier (“f78375b1c487e03c9438c729345e54db9d20cfa2ac1fc3494b6eb60872e74778”);

• UUID short identifier (“f78375b1c487”);

• Name (“jonah”).

Podman generates a UUID for each container, and if a name is not assigned to the container with --name
then it generates a random string name. The name can be useful as a more human-friendly way to identify
containers. This works for both background and foreground containers.

--network=mode, --net
Set the network mode for the container.

Valid mode values are:

• bridge[:OPTIONS,...]: Create a network stack on the default bridge. This is the default for
rootful containers. It is possible to specify these additional options:

• alias=name: Add network-scoped alias for the container.

• ip=IPv4: Specify a static ipv4 address for this container.

• ip=IPv6: Specify a static ipv6 address for this container.

• mac=MAC: Specify a static mac address for this container.

• interface_name: Specify a name for the created network interface inside the container.

For example to set a static ipv4 address and a static mac address, use --network
bridge:ip=10.88.0.10,mac=44:33:22:11:00:99.

• <network name or ID>[:OPTIONS,...]: Connect to a user-defined network; this is the network name
or ID from a network created by podman network create. Using the network name implies the bridge
network mode. It is possible to specify the same options described under the bridge mode above.
Use the --network option multiple times to specify additional networks. For backwards
compatibility it is also possible to specify networks comma separated on the first --network
argument, however this prevents you from using the options described under the bridge section
above.

• none: Create a network namespace for the container but do not configure network interfaces for
it, thus the container has no network connectivity.

• container:id: Reuse another container's network stack.

• host: Do not create a network namespace, the container uses the host's network. Note: The host
mode gives the container full access to local system services such as D-bus and is therefore
considered insecure.

• ns:path: Path to a network namespace to join.

• private: Create a new namespace for the container. This uses the bridge mode for rootful
containers and slirp4netns for rootless ones.

• slirp4netns[:OPTIONS,...]: use slirp4netns(1) to create a user network stack. This is the
default for rootless containers. It is possible to specify these additional options, they can
also be set with network_cmd_options in containers.conf:

• allow_host_loopback=true|false: Allow slirp4netns to reach the host loopback IP (default is
10.0.2.2 or the second IP from slirp4netns cidr subnet when changed, see the cidr option
below). The default is false.

• mtu=MTU: Specify the MTU to use for this network. (Default is 65520).

• cidr=CIDR: Specify ip range to use for this network. (Default is 10.0.2.0/24).

• enable_ipv6=true|false: Enable IPv6. Default is true. (Required for outbound_addr6).

• outbound_addr=INTERFACE: Specify the outbound interface slirp binds to (ipv4 traffic only).

• outbound_addr=IPv4: Specify the outbound ipv4 address slirp binds to.

• outbound_addr6=INTERFACE: Specify the outbound interface slirp binds to (ipv6 traffic only).

• outbound_addr6=IPv6: Specify the outbound ipv6 address slirp binds to.

• port_handler=rootlesskit: Use rootlesskit for port forwarding. Default. Note: Rootlesskit
changes the source IP address of incoming packets to an IP address in the container network
namespace, usually 10.0.2.100. If the application requires the real source IP address, e.g.
web server logs, use the slirp4netns port handler. The rootlesskit port handler is also used
for rootless containers when connected to user-defined networks.

• port_handler=slirp4netns: Use the slirp4netns port forwarding, it is slower than rootlesskit
but preserves the correct source IP address. This port handler cannot be used for user-defined
networks.

• pasta[:OPTIONS,...]: use pasta(1) to create a user-mode networking stack.
This is only supported in rootless mode.
By default, IPv4 and IPv6 addresses and routes, as well as the pod interface name, are copied
from the host. If port forwarding isn't configured, ports are forwarded dynamically as services
are bound on either side (init namespace or container namespace). Port forwarding preserves the
original source IP address. Options described in pasta(1) can be specified as comma-separated
arguments.
In terms of pasta(1) options, --config-net is given by default, in order to configure networking
when the container is started, and --no-map-gw is also assumed by default, to avoid direct
access from container to host using the gateway address. The latter can be overridden by passing
--map-gw in the pasta-specific options (despite not being an actual pasta(1) option).
Also, -t none and -u none are passed if, respectively, no TCP or UDP port forwarding from host
to container is configured, to disable automatic port forwarding based on bound ports.
Similarly, -T none and -U none are given to disable the same functionality from container to
host.
Some examples:

• pasta:--map-gw: Allow the container to directly reach the host using the gateway address.

• pasta:--mtu,1500: Specify a 1500 bytes MTU for the tap interface in the container.

• pasta:--ipv4-only,-a,10.0.2.0,-n,24,-g,10.0.2.2,--dns-forward,10.0.2.3,-m,1500,--no-ndp,--no-
dhcpv6,--no-dhcp, equivalent to default slirp4netns(1) options: disable IPv6, assign
10.0.2.0/24 to the tap0 interface in the container, with gateway 10.0.2.3, enable DNS
forwarder reachable at 10.0.2.3, set MTU to 1500 bytes, disable NDP, DHCPv6 and DHCP support.

• pasta:-I,tap0,--ipv4-only,-a,10.0.2.0,-n,24,-g,10.0.2.2,--dns-forward,10.0.2.3,--no-ndp,--no-
dhcpv6,--no-dhcp, equivalent to default slirp4netns(1) options with Podman overrides: same as
above, but leave the MTU to 65520 bytes

• pasta:-t,auto,-u,auto,-T,auto,-U,auto: enable automatic port forwarding based on observed
bound ports from both host and container sides

• pasta:-T,5201: enable forwarding of TCP port 5201 from container to host, using the loopback
interface instead of the tap interface for improved performance

NOTE: For backward compatibility reasons, if there is an existing network named pasta, Podman uses
it instead of the pasta mode."?

Invalid if using --dns, --dns-option, or --dns-search with --network set to none or container:id.

If used together with --pod, the container joins the pod's network namespace.

--network-alias=alias
Add a network-scoped alias for the container, setting the alias for all networks that the container
joins. To set a name only for a specific network, use the alias option as described under the --network
option. If the network has DNS enabled (podman network inspect -f {{.DNSEnabled}} <name>), these aliases
can be used for name resolution on the given network. This option can be specified multiple times. NOTE:
When using CNI a container only has access to aliases on the first network that it joins. This limitation
does not exist with netavark/aardvark-dns.

--no-healthcheck
Disable any defined healthchecks for container.

--no-hosts
Do not create /etc/hosts for the container. By default, Podman manages /etc/hosts, adding the
container's own IP address and any hosts from --add-host. --no-hosts disables this, and the image's
/etc/hosts is preserved unmodified.

This option conflicts with --add-host.

--oom-kill-disable
Whether to disable OOM Killer for the container or not.

This flag is not supported on cgroups V2 systems.

--oom-score-adj=num
Tune the host's OOM preferences for containers (accepts values from -1000 to 1000).

When running in rootless mode, the specified value can't be lower than the oom_score_adj for the current
process. In this case, the oom-score-adj is clamped to the current process value.

--os=OS
Override the OS, defaults to hosts, of the image to be pulled. For example, windows. Unless overridden,
subsequent lookups of the same image in the local storage matches this OS, regardless of the host.

--passwd
Allow Podman to add entries to /etc/passwd and /etc/group when used in conjunction with the --user
option. This is used to override the Podman provided user setup in favor of entrypoint configurations
such as libnss-extrausers.

--passwd-entry=ENTRY
Customize the entry that is written to the /etc/passwd file within the container when --passwd is used.

The variables $USERNAME, $UID, $GID, $NAME, $HOME are automatically replaced with their value at runtime.

--personality=persona
Personality sets the execution domain via Linux personality(2).

--pid=mode
Set the PID namespace mode for the container. The default is to create a private PID namespace for the
container.

• container:id: join another container's PID namespace;

• host: use the host's PID namespace for the container. Note the host mode gives the container
full access to local PID and is therefore considered insecure;

• ns:path: join the specified PID namespace;

• private: create a new namespace for the container (default).

--pidfile=path
When the pidfile location is specified, the container process' PID is written to the pidfile. (This
option is not available with the remote Podman client, including Mac and Windows (excluding WSL2)
machines) If the pidfile option is not specified, the container process' PID is written to
/run/containers/storage/${storage-driver}-containers/$CID/userdata/pidfile.

After the container is started, the location for the pidfile can be discovered with the following podman
inspect command:

$ podman inspect --format '{{ .PidFile }}' $CID
/run/containers/storage/${storage-driver}-containers/$CID/userdata/pidfile

--pids-limit=limit
Tune the container's pids limit. Set to -1 to have unlimited pids for the container. The default is 2048
on systems that support "pids" cgroup controller.

--platform=OS/ARCH
Specify the platform for selecting the image. (Conflicts with --arch and --os) The --platform option can
be used to override the current architecture and operating system. Unless overridden, subsequent lookups
of the same image in the local storage matches this platform, regardless of the host.

--pod=name
Run container in an existing pod. Podman makes the pod automatically if the pod name is prefixed with
new:. To make a pod with more granular options, use the podman pod create command before creating a
container. When a container is run with a pod with an infra-container, the infra-container is started
first.

--pod-id-file=file
Run container in an existing pod and read the pod's ID from the specified file. When a container is run
within a pod which has an infra-container, the infra-container starts first.

--preserve-fds=N
Pass down to the process N additional file descriptors (in addition to 0, 1, 2). The total FDs are 3+N.
(This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2)
machines)

--privileged
Give extended privileges to this container. The default is false.

By default, Podman containers are unprivileged (=false) and cannot, for example, modify parts of the
operating system. This is because by default a container is only allowed limited access to devices. A
"privileged" container is given the same access to devices as the user launching the container, with the
exception of virtual consoles (/dev/tty\d+) when running in systemd mode (--systemd=always).

A privileged container turns off the security features that isolate the container from the host. Dropped
Capabilities, limited devices, read-only mount points, Apparmor/SELinux separation, and Seccomp filters
are all disabled. Due to the disabled security features, the privileged field should almost never be set
as containers can easily break out of confinement.

Containers running in a user namespace (e.g., rootless containers) cannot have more privileges than the
user that launched them.

--publish, -p=[[ip:][hostPort]:]containerPort[/protocol]
Publish a container's port, or range of ports, to the host.

Both hostPort and containerPort can be specified as a range of ports. When specifying ranges for both,
the number of container ports in the range must match the number of host ports in the range.

If host IP is set to 0.0.0.0 or not set at all, the port is bound on all IPs on the host.

By default, Podman publishes TCP ports. To publish a UDP port instead, give udp as protocol. To publish
both TCP and UDP ports, set --publish twice, with tcp, and udp as protocols respectively. Rootful
containers can also publish ports using the sctp protocol.

Host port does not have to be specified (e.g. podman run -p 127.0.0.1::80). If it is not, the container
port is randomly assigned a port on the host.

Use podman port to see the actual mapping: podman port $CONTAINER $CONTAINERPORT.

Note that the network drivers macvlan and ipvlan do not support port forwarding, it will have no effect
on these networks.

Note: If a container runs within a pod, it is not necessary to publish the port for the containers in the
pod. The port must only be published by the pod itself. Pod network stacks act like the network stack on
the host - meaning a variety of containers in the pod and programs in the container all share a single
interface, IP address, and associated ports. If one container binds to a port, no other container can use
that port within the pod while it is in use. Containers in the pod can also communicate over localhost by
having one container bind to localhost in the pod, and another connect to that port.

--publish-all, -P
Publish all exposed ports to random ports on the host interfaces. The default is false.

When set to true, publish all exposed ports to the host interfaces. If the operator uses -P (or -p) then
Podman makes the exposed port accessible on the host and the ports are available to any client that can
reach the host.

When using this option, Podman binds any exposed port to a random port on the host within an ephemeral
port range defined by /proc/sys/net/ipv4/ip_local_port_range. To find the mapping between the host ports
and the exposed ports, use podman port.

--pull=policy
Pull image policy. The default is missing.

• always: Always pull the image and throw an error if the pull fails.

• missing: Pull the image only when the image is not in the local containers storage. Throw an
error if no image is found and the pull fails.

• never: Never pull the image but use the one from the local containers storage. Throw an error
if no image is found.

• newer: Pull if the image on the registry is newer than the one in the local containers storage.
An image is considered to be newer when the digests are different. Comparing the time stamps is
prone to errors. Pull errors are suppressed if a local image was found.

--quiet, -q
Suppress output information when pulling images

--rdt-class=intel-rdt-class-of-service
Rdt-class sets the class of service (CLOS or COS) for the container to run in. Based on the Cache
Allocation Technology (CAT) feature that is part of Intel's Resource Director Technology (RDT) feature
set, all container processes will run within the pre-configured COS, representing a part of the cache.
The COS has to be created and configured using a pseudo file system (usually mounted at /sys/fs/resctrl)
that the resctrl kernel driver provides. Assigning the container to a COS requires root privileges and
thus doesn't work in a rootless environment. Currently, the feature is only supported using runc as a
runtime. See ⟨https://docs.kernel.org/arch/x86/resctrl.html⟩ for more details on creating a COS before a
container can be assigned to it.

--read-only
Mount the container's root filesystem as read-only.

By default, container root filesystems are writable, allowing processes to write files anywhere. By
specifying the --read-only flag, the containers root filesystem are mounted read-only prohibiting any
writes.

--read-only-tmpfs
When running --read-only containers, mount a read-write tmpfs on /dev, /dev/shm, /run, /tmp, and
/var/tmp. The default is true.

┌─────────────┬───────────────────┬─────┬──────────────────────┐
│ --read-only │ --read-only-tmpfs │ / │ /run, /tmp, /var/tmp │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ true │ true │ r/o │ r/w │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ true │ false │ r/o │ r/o │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ false │ false │ r/w │ r/w │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ false │ true │ r/w │ r/w │
└─────────────┴───────────────────┴─────┴──────────────────────┘

When --read-only=true and --read-only-tmpfs=true additional tmpfs are mounted on the /tmp, /run, and
/var/tmp directories.

When --read-only=true and --read-only-tmpfs=false /dev and /dev/shm are marked Read/Only and no tmpfs are
mounted on /tmp, /run and /var/tmp. The directories are exposed from the underlying image, meaning they
are read-only by default. This makes the container totally read-only. No writable directories exist
within the container. In this mode writable directories need to be added via external volumes or mounts.

By default, when --read-only=false, the /dev and /dev/shm are read/write, and the /tmp, /run, and
/var/tmp are read/write directories from the container image.

--replace
If another container with the same name already exists, replace and remove it. The default is false.

--requires=container
Specify one or more requirements. A requirement is a dependency container that is started before this
container. Containers can be specified by name or ID, with multiple containers being separated by
commas.

--restart=policy
Restart policy to follow when containers exit. Restart policy does not take effect if a container is
stopped via the podman kill or podman stop commands.

Valid policy values are:

• no : Do not restart containers on exit

• never : Synonym for no; do not restart containers on exit

• on-failure[:max_retries] : Restart containers when they exit with a non-zero exit code, retrying
indefinitely or until the optional max_retries count is hit

• always : Restart containers when they exit, regardless of status, retrying
indefinitely

• unless-stopped : Identical to always

Podman provides a systemd unit file, podman-restart.service, which restarts containers after a system
reboot.

When running containers in systemd services, use the restart functionality provided by systemd. In other
words, do not use this option in a container unit, instead set the Restart= systemd directive in the
[Service] section. See podman-systemd.unit(5) and systemd.service(5).

--rm
Automatically remove the container and any anonymous unnamed volume associated with the container when it
exits. The default is false.

--rmi
After exit of the container, remove the image unless another container is using it. Implies --rm on the
new container. The default is false.

--rootfs
If specified, the first argument refers to an exploded container on the file system.

This is useful to run a container without requiring any image management, the rootfs of the container is
assumed to be managed externally.

Overlay Rootfs Mounts

The :O flag tells Podman to mount the directory from the rootfs path as storage using the overlay file
system. The container processes can modify content within the mount point which is stored in the
container storage in a separate directory. In overlay terms, the source directory is the lower, and the
container storage directory is the upper. Modifications to the mount point are destroyed when the
container finishes executing, similar to a tmpfs mount point being unmounted.

Note: On SELinux systems, the rootfs needs the correct label, which is by default
unconfined_u:object_r:container_file_t:s0.

idmap

If idmap is specified, create an idmapped mount to the target user namespace in the container. The idmap
option supports a custom mapping that can be different than the user namespace used by the container.
The mapping can be specified after the idmap option like: idmap=uids=0-1-10#10-11-10;gids=0-100-10. For
each triplet, the first value is the start of the backing file system IDs that are mapped to the second
value on the host. The length of this mapping is given in the third value. Multiple ranges are
separated with #.

--sdnotify=container | conmon | healthy | ignore
Determines how to use the NOTIFY_SOCKET, as passed with systemd and Type=notify.

Default is container, which means allow the OCI runtime to proxy the socket into the container to receive
ready notification. Podman sets the MAINPID to conmon's pid. The conmon option sets MAINPID to conmon's
pid, and sends READY when the container has started. The socket is never passed to the runtime or the
container. The healthy option sets MAINPID to conmon's pid, and sends READY when the container has
turned healthy; requires a healthcheck to be set. The socket is never passed to the runtime or the
container. The ignore option removes NOTIFY_SOCKET from the environment for itself and child processes,
for the case where some other process above Podman uses NOTIFY_SOCKET and Podman does not use it.

--seccomp-policy=policy
Specify the policy to select the seccomp profile. If set to image, Podman looks for a
"io.containers.seccomp.profile" label in the container-image config and use its value as a seccomp
profile. Otherwise, Podman follows the default policy by applying the default profile unless specified
otherwise via --security-opt seccomp as described below.

Note that this feature is experimental and may change in the future.

--secret=secret[,opt=opt ...]
Give the container access to a secret. Can be specified multiple times.

A secret is a blob of sensitive data which a container needs at runtime but is not stored in the image or
in source control, such as usernames and passwords, TLS certificates and keys, SSH keys or other
important generic strings or binary content (up to 500 kb in size).

When secrets are specified as type mount, the secrets are copied and mounted into the container when a
container is created. When secrets are specified as type env, the secret is set as an environment
variable within the container. Secrets are written in the container at the time of container creation,
and modifying the secret using podman secret commands after the container is created affects the secret
inside the container.

Secrets and its storage are managed using the podman secret command.

Secret Options

• type=mount|env : How the secret is exposed to the container.
mount mounts the secret into the container as a file.
env exposes the secret as an environment variable.
Defaults to mount.

• target=target : Target of secret.
For mounted secrets, this is the path to the secret inside the container.
If a fully qualified path is provided, the secret is mounted at that
location.
Otherwise, the secret is mounted to
/run/secrets/target for linux containers or
/var/run/secrets/target for freebsd containers.
If the target is not set, the secret is mounted to /run/secrets/secretname
by default.
For env secrets, this is the environment variable key. Defaults to
secretname.

• uid=0 : UID of secret. Defaults to 0. Mount secret type only.

• gid=0 : GID of secret. Defaults to 0. Mount secret type only.

• mode=0 : Mode of secret. Defaults to 0444. Mount secret type only.

Examples

Mount at /my/location/mysecret with UID 1:

--secret mysecret,target=/my/location/mysecret,uid=1

Mount at /run/secrets/customtarget with mode 0777:

--secret mysecret,target=customtarget,mode=0777

Create a secret environment variable called ENVSEC:

--secret mysecret,type=env,target=ENVSEC

--security-opt=option
Security Options

• apparmor=unconfined : Turn off apparmor confinement for the container

• apparmor=alternate-profile : Set the apparmor confinement profile for the container

• label=user:USER: Set the label user for the container processes

• label=role:ROLE: Set the label role for the container processes

• label=type:TYPE: Set the label process type for the container processes

• label=level:LEVEL: Set the label level for the container processes

• label=filetype:TYPE: Set the label file type for the container files

• label=disable: Turn off label separation for the container

Note: Labeling can be disabled for all containers by setting label=false in the containers.conf
(/etc/containers/containers.conf or $HOME/.config/containers/containers.conf) file.

• label=nested: Allows SELinux modifications within the container. Containers are allowed to
modify SELinux labels on files and processes, as long as SELinux policy allows. Without nested,
containers view SELinux as disabled, even when it is enabled on the host. Containers are
prevented from setting any labels.

• mask=/path/1:/path/2: The paths to mask separated by a colon. A masked path cannot be accessed
inside the container.

• no-new-privileges: Disable container processes from gaining additional privileges.

• seccomp=unconfined: Turn off seccomp confinement for the container.

• seccomp=profile.json: JSON file to be used as a seccomp filter. Note that the
io.podman.annotations.seccomp annotation is set with the specified value as shown in podman
inspect.

• proc-opts=OPTIONS : Comma-separated list of options to use for the /proc mount. More details for
the possible mount options are specified in the proc(5) man page.

• unmask=ALL or /path/1:/path/2, or shell expanded paths (/proc/*): Paths to unmask separated by a
colon. If set to ALL, it unmasks all the paths that are masked or made read-only by default.
The default masked paths are /proc/acpi, /proc/kcore, /proc/keys, /proc/latency_stats,
/proc/sched_debug, /proc/scsi, /proc/timer_list, /proc/timer_stats, /sys/firmware, and
/sys/fs/selinux, /sys/devices/virtual/powercap. The default paths that are read-only are
/proc/asound, /proc/bus, /proc/fs, /proc/irq, /proc/sys, /proc/sysrq-trigger, /sys/fs/cgroup.

Note: Labeling can be disabled for all containers by setting label=false in the containers.conf(5) file.

--shm-size=number[unit]
Size of /dev/shm. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes). If the unit
is omitted, the system uses bytes. If the size is omitted, the default is 64m. When size is 0, there is
no limit on the amount of memory used for IPC by the container. This option conflicts with --ipc=host.

--shm-size-systemd=number[unit]
Size of systemd-specific tmpfs mounts such as /run, /run/lock, /var/log/journal and /tmp. A unit can be
b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes). If the unit is omitted, the system uses
bytes. If the size is omitted, the default is 64m. When size is 0, the usage is limited to 50% of the
host's available memory.

--sig-proxy
Proxy received signals to the container process. SIGCHLD, SIGURG, SIGSTOP, and SIGKILL are not proxied.

The default is true.

--stop-signal=signal
Signal to stop a container. Default is SIGTERM.

--stop-timeout=seconds
Timeout to stop a container. Default is 10. Remote connections use local containers.conf for defaults.

--subgidname=name
Run the container in a new user namespace using the map with name in the /etc/subgid file. If running
rootless, the user needs to have the right to use the mapping. See subgid(5). This flag conflicts with
--userns and --gidmap.

--subuidname=name
Run the container in a new user namespace using the map with name in the /etc/subuid file. If running
rootless, the user needs to have the right to use the mapping. See subuid(5). This flag conflicts with
--userns and --uidmap.

--sysctl=name=value
Configure namespaced kernel parameters at runtime.

For the IPC namespace, the following sysctls are allowed:

• kernel.msgmax

• kernel.msgmnb

• kernel.msgmni

• kernel.sem

• kernel.shmall

• kernel.shmmax

• kernel.shmmni

• kernel.shm_rmid_forced

• Sysctls beginning with fs.mqueue.*

Note: if using the --ipc=host option, the above sysctls are not allowed.

For the network namespace, only sysctls beginning with net.* are allowed.

Note: if using the --network=host option, the above sysctls are not allowed.

--systemd=true | false | always
Run container in systemd mode. The default is true.

• true enables systemd mode only when the command executed inside the container is systemd,
/usr/sbin/init, /sbin/init or /usr/local/sbin/init.

• false disables systemd mode.

• always enforces the systemd mode to be enabled.

Running the container in systemd mode causes the following changes:

• Podman mounts tmpfs file systems on the following directories

• /run

• /run/lock

• /tmp

• /sys/fs/cgroup/systemd (on a cgroup v1 system)

• /var/lib/journal

• Podman sets the default stop signal to SIGRTMIN+3.

• Podman sets container_uuid environment variable in the container to the first 32 characters of
the container ID.

• Podman does not mount virtual consoles (/dev/tty\d+) when running with --privileged.

• On cgroup v2, /sys/fs/cgroup is mounted writeable.

This allows systemd to run in a confined container without any modifications.

Note that on SELinux systems, systemd attempts to write to the cgroup file system. Containers writing to
the cgroup file system are denied by default. The container_manage_cgroup boolean must be enabled for
this to be allowed on an SELinux separated system.

setsebool -P container_manage_cgroup true

--timeout=seconds
Maximum time a container is allowed to run before conmon sends it the kill signal. By default containers
run until they exit or are stopped by podman stop.

--tls-verify
Require HTTPS and verify certificates when contacting registries (default: true). If explicitly set to
true, TLS verification is used. If set to false, TLS verification is not used. If not specified, TLS
verification is used unless the target registry is listed as an insecure registry in containers-
registries.conf(5)

--tmpfs=fs
Create a tmpfs mount.

Mount a temporary filesystem (tmpfs) mount into a container, for example:

$ podman run -d --tmpfs /tmp:rw,size=787448k,mode=1777 my_image

This command mounts a tmpfs at /tmp within the container. The supported mount options are the same as the
Linux default mount flags. If no options are specified, the system uses the following options:
rw,noexec,nosuid,nodev.

--tty, -t
Allocate a pseudo-TTY. The default is false.

When set to true, Podman allocates a pseudo-tty and attach to the standard input of the container. This
can be used, for example, to run a throwaway interactive shell.

NOTE: The --tty flag prevents redirection of standard output. It combines STDOUT and STDERR, it can
insert control characters, and it can hang pipes. This option is only used when run interactively in a
terminal. When feeding input to Podman, use -i only, not -it.

echo "asdf" | podman run --rm -i someimage /bin/cat

--tz=timezone
Set timezone in container. This flag takes area-based timezones, GMT time, as well as local, which sets
the timezone in the container to match the host machine. See /usr/share/zoneinfo/ for valid timezones.
Remote connections use local containers.conf for defaults

--uidmap=[flags]container_uid:from_uid[:amount]
Run the container in a new user namespace using the supplied UID mapping. This option conflicts with the
--userns and --subuidname options. This option provides a way to map host UIDs to container UIDs. It can
be passed several times to map different ranges.

The possible values of the optional flags are discussed further down on this page. The amount value is
optional and assumed to be 1 if not given.

The from_uid value is based upon the user running the command, either rootful or rootless users.

• rootful user: [flags]container_uid:host_uid[:amount]

• rootless user: [flags]container_uid:intermediate_uid[:amount]

Rootful mappings

When podman run is called by a privileged user, the option --uidmap works as a direct mapping between
host UIDs and container UIDs.

host UID -> container UID

The amount specifies the number of consecutive UIDs that is mapped. If for example amount is 4 the
mapping looks like:

┌──────────────┬───────────────────┐
│ host UID │ container UID │
├──────────────┼───────────────────┤
│ from_uid │ container_uid │
├──────────────┼───────────────────┤
│ from_uid + 1 │ container_uid + 1 │
├──────────────┼───────────────────┤
│ from_uid + 2 │ container_uid + 2 │
├──────────────┼───────────────────┤
│ from_uid + 3 │ container_uid + 3 │
└──────────────┴───────────────────┘

Rootless mappings

When podman run is called by an unprivileged user (i.e. running rootless), the value from_uid is
interpreted as an "intermediate UID". In the rootless case, host UIDs are not mapped directly to
container UIDs. Instead the mapping happens over two mapping steps:

host UID -> intermediate UID -> container UID

The --uidmap option only influences the second mapping step.

The first mapping step is derived by Podman from the contents of the file /etc/subuid and the UID of the
user calling Podman.

First mapping step:

┌─────────────────────┬──────────────────┐
│ host UID │ intermediate UID │
├─────────────────────┼──────────────────┤
│ UID for Podman user │ 0 │
├─────────────────────┼──────────────────┤
│ 1st subordinate UID │ 1 │
├─────────────────────┼──────────────────┤
│ 2nd subordinate UID │ 2 │
├─────────────────────┼──────────────────┤
│ 3rd subordinate UID │ 3 │
├─────────────────────┼──────────────────┤
│ nth subordinate UID │ n │
└─────────────────────┴──────────────────┘

To be able to use intermediate UIDs greater than zero, the user needs to have subordinate UIDs configured
in /etc/subuid. See subuid(5).

The second mapping step is configured with --uidmap.

If for example amount is 5 the second mapping step looks like:

┌──────────────────┬───────────────────┐
│ intermediate UID │ container UID │
├──────────────────┼───────────────────┤
│ from_uid │ container_uid │
├──────────────────┼───────────────────┤
│ from_uid + 1 │ container_uid + 1 │
├──────────────────┼───────────────────┤
│ from_uid + 2 │ container_uid + 2 │
├──────────────────┼───────────────────┤
│ from_uid + 3 │ container_uid + 3 │
├──────────────────┼───────────────────┤
│ from_uid + 4 │ container_uid + 4 │
└──────────────────┴───────────────────┘

When running as rootless, Podman uses all the ranges configured in the /etc/subuid file.

The current user ID is mapped to UID=0 in the rootless user namespace. Every additional range is added
sequentially afterward:

┌───────────────────────┬─────────────────────────┬──────────────────────┐
│ host │ rootless user namespace │ length │
├───────────────────────┼─────────────────────────┼──────────────────────┤
│ $UID │ 0 │ 1 │
├───────────────────────┼─────────────────────────┼──────────────────────┤
│ 1 │ $FIRST_RANGE_ID │ $FIRST_RANGE_LENGTH │
├───────────────────────┼─────────────────────────┼──────────────────────┤
│ 1+$FIRST_RANGE_LENGTH │ $SECOND_RANGE_ID │ $SECOND_RANGE_LENGTH │
└───────────────────────┴─────────────────────────┴──────────────────────┘

Referencing a host ID from the parent namespace

As a rootless user, the given host ID in --uidmap or --gidmap is mapped from the intermediate namespace
generated by Podman. Sometimes it is desirable to refer directly at the host namespace. It is possible to
manually do so, by running podman unshare cat /proc/self/gid_map, finding the desired host id at the
second column of the output, and getting the corresponding intermediate id from the first column.

Podman can perform all that by preceding the host id in the mapping with the @ symbol. For instance, by
specifying --gidmap 100000:@2000:1, podman will look up the intermediate id corresponding to host id 2000
and it will map the found intermediate id to the container id 100000. The given host id must have been
subordinated (otherwise it would not be mapped into the intermediate space in the first place).

If the length is greater than one, for instance with --gidmap 100000:@2000:2, Podman will map host ids
2000 and 2001 to 100000 and 100001, respectively, regardless of how the intermediate mapping is defined.

Extending previous mappings

Some mapping modifications may be cumbersome. For instance, a user starts with a mapping such as
--gidmap="0:0:65000", that needs to be changed such as the parent id 1000 is mapped to container id
100000 instead, leaving container id 1 unassigned. The corresponding --gidmap becomes --gidmap="0:0:1"
--gidmap="2:2:65534" --gidmap="100000:1:1".

This notation can be simplified using the + flag, that takes care of breaking previous mappings removing
any conflicting assignment with the given mapping. The flag is given before the container id as follows:
--gidmap="0:0:65000" --gidmap="+100000:1:1"

┌──────┬─────────────┬─────────────────────────────┐
│ Flag │ Example │ Description │
├──────┼─────────────┼─────────────────────────────┤
│ + │ +100000:1:1 │ Extend the previous mapping │
└──────┴─────────────┴─────────────────────────────┘

This notation leads to gaps in the assignment, so it may be convenient to fill those gaps afterwards:
--gidmap="0:0:65000" --gidmap="+100000:1:1" --gidmap="1:65001:1"

One specific use case for this flag is in the context of rootless users. A rootless user may specify
mappings with the + flag as in --gidmap="+100000:1:1". Podman will then "fill the gaps" starting from
zero with all the remaining intermediate ids. This is convenient when a user wants to map a specific
intermediate id to a container id, leaving the rest of subordinate ids to be mapped by Podman at will.

Passing only one of --uidmap or --gidmap

Usually, subordinated user and group ids are assigned simultaneously, and for any user the subordinated
user ids match the subordinated group ids. For convenience, if only one of --uidmap or --gidmap is
given, podman assumes the mapping refers to both UIDs and GIDs and applies the given mapping to both. If
only one value of the two needs to be changed, the mappings should include the u or the g flags to
specify that they only apply to UIDs or GIDs and should not be copied over.

┌──────┬───────────────┬──────────────────────────────┐
│ flag │ Example │ Description │
├──────┼───────────────┼──────────────────────────────┤
│ u │ u20000:2000:1 │ The mapping only applies to │
│ │ │ UIDs │
├──────┼───────────────┼──────────────────────────────┤
│ g │ g10000:1000:1 │ The mapping only applies to │
│ │ │ GIDs │
└──────┴───────────────┴──────────────────────────────┘

For instance given the command

podman run --gidmap "0:0:1000" --gidmap "g2000:2000:1"

Since no --uidmap is given, the --gidmap is copied to --uidmap, giving a command equivalent to

podman run --gidmap "0:0:1000" --gidmap "2000:2000:1" --uidmap "0:0:1000"

The --gidmap "g2000:2000:1" used the g flag and therefore it was not copied to --uidmap.

Rootless mapping of additional host GIDs

A rootless user may desire to map a specific host group that has already been subordinated within
/etc/subgid without specifying the rest of the mapping.

This can be done with --gidmap "+gcontainer_gid:@host_gid"

Where:

• The host GID is given through the @ symbol

• The mapping of this GID is not copied over to --usermap thanks to the g flag.

• The rest of the container IDs will be mapped starting from 0 to n, with all the remaining
subordinated GIDs, thanks to the + flag.

For instance, if a user belongs to the group 2000 and that group is subordinated to that user (with
usermod --add-subgids 2000-2000 $USER), the user can map the group into the container with:
--gidmap=+g100000:@2000.

If this mapping is combined with the option, --group-add=keep-groups, the process in the container will
belong to group 100000, and files belonging to group 2000 in the host will appear as being owned by group
100000 inside the container.

podman run --group-add=keep-groups --gidmap="+g100000:@2000" ...

No subordinate UIDs

Even if a user does not have any subordinate UIDs in /etc/subuid, --uidmap can be used to map the normal
UID of the user to a container UID by running podman run --uidmap $container_uid:0:1 --user
$container_uid ....

Pods

The --uidmap option cannot be called in conjunction with the --pod option as a uidmap cannot be set on
the container level when in a pod.

--ulimit=option
Ulimit options. Sets the ulimits values inside of the container.

--ulimit with a soft and hard limit in the format =[:]. For example:

$ podman run --ulimit nofile=1024:1024 --rm ubi9 ulimit -n 1024

Set -1 for the soft or hard limit to set the limit to the maximum limit of the current process. In
rootful mode this is often unlimited.

Use host to copy the current configuration from the host.

Don't use nproc with the ulimit flag as Linux uses nproc to set the maximum number of processes available
to a user, not to a container.

Use the --pids-limit option to modify the cgroup control to limit the number of processes within a
container.

--umask=umask
Set the umask inside the container. Defaults to 0022. Remote connections use local containers.conf for
defaults

--unsetenv=env
Unset default environment variables for the container. Default environment variables include variables
provided natively by Podman, environment variables configured by the image, and environment variables
from containers.conf.

--unsetenv-all
Unset all default environment variables for the container. Default environment variables include
variables provided natively by Podman, environment variables configured by the image, and environment
variables from containers.conf.

--user, -u=user[:group]
Sets the username or UID used and, optionally, the groupname or GID for the specified command. Both user
and group may be symbolic or numeric.

Without this argument, the command runs as the user specified in the container image. Unless overridden
by a USER command in the Containerfile or by a value passed to this option, this user generally defaults
to root.

When a user namespace is not in use, the UID and GID used within the container and on the host match.
When user namespaces are in use, however, the UID and GID in the container may correspond to another UID
and GID on the host. In rootless containers, for example, a user namespace is always used, and root in
the container by default corresponds to the UID and GID of the user invoking Podman.

--userns=mode
Set the user namespace mode for the container.

If --userns is not set, the default value is determined as follows. - If --pod is set, --userns is
ignored and the user namespace of the pod is used. - If the environment variable PODMAN_USERNS is set
its value is used. - If userns is specified in containers.conf this value is used. - Otherwise,
--userns=host is assumed.

--userns="" (i.e., an empty string) is an alias for --userns=host.

This option is incompatible with --gidmap, --uidmap, --subuidname and --subgidname.

Rootless user --userns=Key mappings:

┌─────────────────────────┬───────────┬──────────────────────────────┐
│ Key │ Host User │ Container User │
├─────────────────────────┼───────────┼──────────────────────────────┤
│ auto │ $UID │ nil (Host User UID is not │
│ │ │ mapped into container.) │
├─────────────────────────┼───────────┼──────────────────────────────┤
│ host │ $UID │ 0 (Default User account │
│ │ │ mapped to root user in │
│ │ │ container.) │
├─────────────────────────┼───────────┼──────────────────────────────┤
│ keep-id │ $UID │ $UID (Map user account to │
│ │ │ same UID within container.) │
├─────────────────────────┼───────────┼──────────────────────────────┤
│ keep-id:uid=200,gid=210 │ $UID │ 200:210 (Map user account to │
│ │ │ specified UID, GID value │
│ │ │ within container.) │
├─────────────────────────┼───────────┼──────────────────────────────┤
│ nomap │ $UID │ nil (Host User UID is not │
│ │ │ mapped into container.) │
└─────────────────────────┴───────────┴──────────────────────────────┘

Valid mode values are:

auto[:OPTIONS,...]: automatically create a unique user namespace.

• rootful mode: The --userns=auto flag requires that the user name containers be specified in the
/etc/subuid and /etc/subgid files, with an unused range of subordinate user IDs that Podman
containers are allowed to allocate.

Example: containers:2147483647:2147483648.

• rootless mode: The users range from the /etc/subuid and /etc/subgid files will be used. Note
running a single container without using --userns=auto will use the entire range of UIDs and not
allow further subdividing. See subuid(5).

Podman allocates unique ranges of UIDs and GIDs from the containers subordinate user IDs. The size of the
ranges is based on the number of UIDs required in the image. The number of UIDs and GIDs can be
overridden with the size option.

The option --userns=keep-id uses all the subuids and subgids of the user. The option --userns=nomap uses
all the subuids and subgids of the user except the user's own ID. Using --userns=auto when starting new
containers does not work as long as any containers exist that were started with --userns=keep-id or
--userns=nomap.

Valid auto options:

• gidmapping=CONTAINER_GID:HOST_GID:SIZE: to force a GID mapping to be present in the user
namespace.

• size=SIZE: to specify an explicit size for the automatic user namespace. e.g.
--userns=auto:size=8192. If size is not specified, auto estimates a size for the user namespace.

• uidmapping=CONTAINER_UID:HOST_UID:SIZE: to force a UID mapping to be present in the user
namespace.

container:id: join the user namespace of the specified container.

host or "" (empty string): run in the user namespace of the caller. The processes running in the
container have the same privileges on the host as any other process launched by the calling user.

keep-id: creates a user namespace where the current user's UID:GID are mapped to the same values in the
container. For containers created by root, the current mapping is created into a new user namespace.

Valid keep-id options:

• uid=UID: override the UID inside the container that is used to map the current user to.

• gid=GID: override the GID inside the container that is used to map the current user to.

nomap: creates a user namespace where the current rootless user's UID:GID are not mapped into the
container. This option is not allowed for containers created by the root user.

ns:namespace: run the container in the given existing user namespace.

--uts=mode
Set the UTS namespace mode for the container. The following values are supported:

• host: use the host's UTS namespace inside the container.

• private: create a new namespace for the container (default).

• ns:[path]: run the container in the given existing UTS namespace.

• container:[container]: join the UTS namespace of the specified container.

--variant=VARIANT
Use VARIANT instead of the default architecture variant of the container image. Some images can use
multiple variants of the arm architectures, such as arm/v5 and arm/v7.

--volume, -v=[[SOURCE-VOLUME|HOST-DIR:]CONTAINER-DIR[:OPTIONS]]
Create a bind mount. If -v /HOST-DIR:/CONTAINER-DIR is specified, Podman bind mounts /HOST-DIR from the
host into /CONTAINER-DIR in the Podman container. Similarly, -v SOURCE-VOLUME:/CONTAINER-DIR mounts the
named volume from the host into the container. If no such named volume exists, Podman creates one. If no
source is given, the volume is created as an anonymously named volume with a randomly generated name, and
is removed when the container is removed via the --rm flag or the podman rm --volumes command.

(Note when using the remote client, including Mac and Windows (excluding WSL2) machines, the volumes are
mounted from the remote server, not necessarily the client machine.)

The OPTIONS is a comma-separated list and can be: [1] ⟨#Footnote1⟩

• rw|ro

• z|Z

• [O]

• [U]

• [no]copy

• [no]dev

• [no]exec

• [no]suid

• [r]bind

• [r]shared|[r]slave|[r]private[r]unbindable

• idmap[=options]

The CONTAINER-DIR must be an absolute path such as /src/docs. The volume is mounted into the container at
this directory.

If a volume source is specified, it must be a path on the host or the name of a named volume. Host paths
are allowed to be absolute or relative; relative paths are resolved relative to the directory Podman is
run in. If the source does not exist, Podman returns an error. Users must pre-create the source files or
directories.

Any source that does not begin with a . or / is treated as the name of a named volume. If a volume with
that name does not exist, it is created. Volumes created with names are not anonymous, and they are not
removed by the --rm option and the podman rm --volumes command.

Specify multiple -v options to mount one or more volumes into a container.

Write Protected Volume Mounts

Add :ro or :rw option to mount a volume in read-only or read-write mode, respectively. By default, the
volumes are mounted read-write. See examples.

Chowning Volume Mounts

By default, Podman does not change the owner and group of source volume directories mounted into
containers. If a container is created in a new user namespace, the UID and GID in the container may
correspond to another UID and GID on the host.

The :U suffix tells Podman to use the correct host UID and GID based on the UID and GID within the
container, to change recursively the owner and group of the source volume. Chowning walks the file system
under the volume and changes the UID/GID on each file. If the volume has thousands of inodes, this
process takes a long time, delaying the start of the container.

Warning use with caution since this modifies the host filesystem.

Labeling Volume Mounts

Labeling systems like SELinux require that proper labels are placed on volume content mounted into a
container. Without a label, the security system might prevent the processes running inside the container
from using the content. By default, Podman does not change the labels set by the OS.

To change a label in the container context, add either of two suffixes :z or :Z to the volume mount.
These suffixes tell Podman to relabel file objects on the shared volumes. The z option tells Podman that
two or more containers share the volume content. As a result, Podman labels the content with a shared
content label. Shared volume labels allow all containers to read/write content. The Z option tells Podman
to label the content with a private unshared label Only the current container can use a private volume.
Relabeling walks the file system under the volume and changes the label on each file, if the volume has
thousands of inodes, this process takes a long time, delaying the start of the container. If the volume
was previously relabeled with the z option, Podman is optimized to not relabel a second time. If files
are moved into the volume, then the labels can be manually change with the chcon -Rt container_file_t
PATH command.

Note: Do not relabel system files and directories. Relabeling system content might cause other confined
services on the machine to fail. For these types of containers we recommend disabling SELinux
separation. The option --security-opt label=disable disables SELinux separation for the container. For
example if a user wanted to volume mount their entire home directory into a container, they need to
disable SELinux separation.

$ podman run --security-opt label=disable -v $HOME:/home/user fedora touch /home/user/file

Overlay Volume Mounts

The :O flag tells Podman to mount the directory from the host as a temporary storage using the overlay
file system. The container processes can modify content within the mountpoint which is stored in the
container storage in a separate directory. In overlay terms, the source directory is the lower, and the
container storage directory is the upper. Modifications to the mount point are destroyed when the
container finishes executing, similar to a tmpfs mount point being unmounted.

For advanced users, the overlay option also supports custom non-volatile upperdir and workdir for the
overlay mount. Custom upperdir and workdir can be fully managed by the users themselves, and Podman does
not remove it on lifecycle completion. Example :O,upperdir=/some/upper,workdir=/some/work

Subsequent executions of the container sees the original source directory content, any changes from
previous container executions no longer exist.

One use case of the overlay mount is sharing the package cache from the host into the container to allow
speeding up builds.

Note: The O flag conflicts with other options listed above.

Content mounted into the container is labeled with the private label.
On SELinux systems, labels in the source directory must be readable by the container label.
Usually containers can read/execute container_share_t and can read/write container_file_t. If unable to
change the labels on a source volume, SELinux container separation must be disabled for the container to
work.
- Do not modify the source directory mounted into the container with an overlay mount, it can cause
unexpected failures. Only modify the directory after the container finishes running.

Mounts propagation

By default bind mounted volumes are private. That means any mounts done inside the container is not
visible on host and vice versa. One can change this behavior by specifying a volume mount propagation
property. Making a volume shared mounts done under that volume inside the container is visible on host
and vice versa. Making a volume slave enables only one way mount propagation and that is mounts done on
host under that volume is visible inside container but not the other way around. [1] ⟨#Footnote1⟩

To control mount propagation property of a volume one can use the [r]shared, [r]slave, [r]private or the
[r]unbindable propagation flag. Propagation property can be specified only for bind mounted volumes and
not for internal volumes or named volumes. For mount propagation to work the source mount point (the
mount point where source dir is mounted on) has to have the right propagation properties. For shared
volumes, the source mount point has to be shared. And for slave volumes, the source mount point has to be
either shared or slave. [1] ⟨#Footnote1⟩

To recursively mount a volume and all of its submounts into a container, use the rbind option. By default
the bind option is used, and submounts of the source directory is not mounted into the container.

Mounting the volume with a copy option tells podman to copy content from the underlying destination
directory onto newly created internal volumes. The copy only happens on the initial creation of the
volume. Content is not copied up when the volume is subsequently used on different containers. The copy
option is ignored on bind mounts and has no effect.

Mounting volumes with the nosuid options means that SUID executables on the volume can not be used by
applications to change their privilege. By default volumes are mounted with nosuid.

Mounting the volume with the noexec option means that no executables on the volume can be executed within
the container.

Mounting the volume with the nodev option means that no devices on the volume can be used by processes
within the container. By default volumes are mounted with nodev.

If the HOST-DIR is a mount point, then dev, suid, and exec options are ignored by the kernel.

Use df HOST-DIR to figure out the source mount, then use findmnt -o TARGET,PROPAGATION source-mount-dir
to figure out propagation properties of source mount. If findmnt(1) utility is not available, then one
can look at the mount entry for the source mount point in /proc/self/mountinfo. Look at the "optional
fields" and see if any propagation properties are specified. In there, shared:N means the mount is
shared, master:N means mount is slave, and if nothing is there, the mount is private. [1] ⟨#Footnote1⟩

To change propagation properties of a mount point, use mount(8) command. For example, if one wants to
bind mount source directory /foo, one can do mount --bind /foo /foo and mount --make-private --make-
shared /foo. This converts /foo into a shared mount point. Alternatively, one can directly change
propagation properties of source mount. Say / is source mount for /foo, then use mount --make-shared / to
convert / into a shared mount.

Note: if the user only has access rights via a group, accessing the volume from inside a rootless
container fails.

Idmapped mount

If idmap is specified, create an idmapped mount to the target user namespace in the container. The idmap
option supports a custom mapping that can be different than the user namespace used by the container. The
mapping can be specified after the idmap option like: idmap=uids=0-1-10#10-11-10;gids=0-100-10. For each
triplet, the first value is the start of the backing file system IDs that are mapped to the second value
on the host. The length of this mapping is given in the third value. Multiple ranges are separated with
#.

Use the --group-add keep-groups option to pass the user's supplementary group access into the container.

--volumes-from=CONTAINER[:OPTIONS]
Mount volumes from the specified container(s). Used to share volumes between containers. The options is a
comma-separated list with the following available elements:

• rw|ro

• z

Mounts already mounted volumes from a source container onto another container. CONTAINER may be a name or
ID. To share a volume, use the --volumes-from option when running the target container. Volumes can be
shared even if the source container is not running.

By default, Podman mounts the volumes in the same mode (read-write or read-only) as it is mounted in the
source container. This can be changed by adding a ro or rw option.

To change a label in the container context, add z to the volume mount. This suffix tells Podman to
relabel file objects on the shared volumes. The z option tells Podman that two entities share the volume
content. As a result, Podman labels the content with a shared content label. Shared volume labels allow
all containers to read/write content.

If the location of the volume from the source container overlaps with data residing on a target
container, then the volume hides that data on the target.

--workdir, -w=dir
Working directory inside the container.

The default working directory for running binaries within a container is the root directory (/). The
image developer can set a different default with the WORKDIR instruction. The operator can override the
working directory by using the -w option.

Exit Status

       The exit code from podman run gives information about why the container failed to run or why  it  exited.
       When podman run exits with a non-zero code, the exit codes follow the chroot(1) standard, see below:

       125 The error is with Podman itself

       $ podman run --foo busybox; echo $?
       Error: unknown flag: --foo
       125

       126 The contained command cannot be invoked

       $ podman run busybox /etc; echo $?
       Error: container_linux.go:346: starting container process caused "exec: \"/etc\": permission denied": OCI runtime error
       126

       127 The contained command cannot be found

       $ podman run busybox foo; echo $?
       Error: container_linux.go:346: starting container process caused "exec: \"foo\": executable file not found in $PATH": OCI runtime error
       127

       Exit code contained command exit code

       $ podman run busybox /bin/sh -c 'exit 3'; echo $?
       3

EXAMPLES

   Running container in read-only mode
       During  container  image  development,  containers  often  need to write to the image content. Installing
       packages into /usr, for example.  In  production,  applications  seldom  need  to  write  to  the  image.
       Container applications write to volumes if they need to write to file systems at all. Applications can be
       made  more  secure  by  running  them  in read-only mode using the --read-only switch.  This protects the
       container's image from modification. By default read-only containers can write to temporary data.  Podman
       mounts  a tmpfs on /run and /tmp within the container. If the container does not write to any file system
       within the container, including tmpfs, set --read-only-tmpfs=false.

       $ podman run --read-only -i -t fedora /bin/bash

       $ podman run --read-only --read-only-tmpfs=false --tmpfs /run -i -t fedora /bin/bash

   Exposing shared libraries inside of container as read-only using a glob
       $ podman run --mount type=glob,src=/usr/lib64/libnvidia\*,ro=true -i -t fedora /bin/bash

   Exposing log messages from the container to the host's log
       Bind mount the /dev/log directory to have messages that are logged in  the  container   show  up  in  the
       host's syslog/journal.

       $ podman run -v /dev/log:/dev/log -i -t fedora /bin/bash

       From inside the container test this by sending a message to the log.

       (bash)# logger "Hello from my container"

       Then exit and check the journal.

       (bash)# exit

       $ journalctl -b | grep Hello

       This lists the message sent to the logger.

   Attaching to one or more from STDIN, STDOUT, STDERR
       Without  specifying  the  -a  option,  Podman  attaches everything (stdin, stdout, stderr).  Override the
       default by specifying -a (stdin, stdout, stderr), as in:

       $ podman run -a stdin -a stdout -i -t fedora /bin/bash

   Sharing IPC between containers
       Using shm_server.c available here: https://www.cs.cf.ac.uk/Dave/C/node27.html

       Testing --ipc=host mode:

       Host shows a shared memory segment with 7 pids attached, happens to be from httpd:

       $ sudo ipcs -m

       ------ Shared Memory Segments --------
       key        shmid      owner      perms      bytes      nattch     status
       0x01128e25 0          root       600        1000       7

       Now run a regular container, and it correctly does NOT see the shared memory segment from the host:

       $ podman run -it shm ipcs -m

       ------ Shared Memory Segments --------
       key        shmid      owner      perms      bytes      nattch     status

       Run a container with the new --ipc=host option, and it now sees the shared memory segment from  the  host
       httpd:

       $ podman run -it --ipc=host shm ipcs -m

       ------ Shared Memory Segments --------
       key        shmid      owner      perms      bytes      nattch     status
       0x01128e25 0          root       600        1000       7

       Testing --ipc=container:id mode:

       Start a container with a program to create a shared memory segment:

       $ podman run -it shm bash
       $ sudo shm/shm_server &
       $ sudo ipcs -m

       ------ Shared Memory Segments --------
       key        shmid      owner      perms      bytes      nattch     status
       0x0000162e 0          root       666        27         1

       Create a 2nd container correctly shows no shared memory segment from 1st container:

       $ podman run shm ipcs -m

       ------ Shared Memory Segments --------
       key        shmid      owner      perms      bytes      nattch     status

       Create  a  3rd container using the --ipc=container:id option, now it shows the shared memory segment from
       the first:

       $ podman run -it --ipc=container:ed735b2264ac shm ipcs -m
       $ sudo ipcs -m

       ------ Shared Memory Segments --------
       key        shmid      owner      perms      bytes      nattch     status
       0x0000162e 0          root       666        27         1

   Mapping Ports for External Usage
       The exposed port of an application can be mapped to a host port using the -p flag. For example, an  httpd
       port 80 can be mapped to the host port 8080 using the following:

       $ podman run -p 8080:80 -d -i -t fedora/httpd

   Mounting External Volumes
       To  mount  a  host  directory  as  a container volume, specify the absolute path to the directory and the
       absolute path for the container directory separated  by  a  colon.  If  the  source  is  a  named  volume
       maintained by Podman, it is recommended to use its name rather than the path to the volume. Otherwise the
       volume is considered an orphan and wiped by the podman volume prune command:

       $ podman run -v /var/db:/data1 -i -t fedora bash

       $ podman run -v data:/data2 -i -t fedora bash

       $ podman run -v /var/cache/dnf:/var/cache/dnf:O -ti fedora dnf -y update

       If  the  container  needs  a  writeable mounted volume by a non root user inside the container, use the U
       option. This option tells Podman to chown the source volume to match the default UID and GID used  within
       the container.

       $ podman run -d -e MYSQL_ROOT_PASSWORD=root --user mysql --userns=keep-id -v ~/data:/var/lib/mysql:Z,U mariadb

       Alternatively  if  the  container needs a writable volume by a non root user inside of the container, the
       --userns=keep-id option allows users to specify the UID and GID of the user executing Podman to  specific
       UIDs  and  GIDs within the container. Since the processes running in the container run as the user's UID,
       they can read/write files owned by the user.

       $ podman run -d -e MYSQL_ROOT_PASSWORD=root --user mysql --userns=keep-id:uid=999,gid=999 -v ~/data:/var/lib/mysql:Z mariadb

       Using --mount flags to mount a host directory as a container folder, specify the  absolute  path  to  the
       directory or the volume name, and the absolute path within the container directory:

       $ podman run --mount type=bind,src=/var/db,target=/data1 busybox sh

       $ podman run --mount type=bind,src=volume-name,target=/data1 busybox sh

       When  using  SELinux,  be aware that the host has no knowledge of container SELinux policy. Therefore, in
       the above example, if SELinux policy is enforced, the /var/db directory is not writable to the container.
       A "Permission Denied" message occurs, and an avc: message is added to the host's syslog.

       To work around this, at time of writing this man page, the following command needs to be run in order for
       the proper SELinux policy type label to be attached to the host directory:

       $ chcon -Rt svirt_sandbox_file_t /var/db

       Now, writing to the /data1 volume in the container is allowed and the changes are reflected on  the  host
       in /var/db.

   Using alternative security labeling
       Override  the  default  labeling  scheme  for  each  container by specifying the --security-opt flag. For
       example, specify the MCS/MLS level, a requirement for MLS systems. Specifying the level in the  following
       command allows the same content to be shared between containers.

       podman run --security-opt label=level:s0:c100,c200 -i -t fedora bash

       An MLS example might be:

       $ podman run --security-opt label=level:TopSecret -i -t rhel7 bash

       To disable the security labeling for this container versus running with the

   --permissive flag, use the following command:
       $ podman run --security-opt label=disable -i -t fedora bash

       Tighten  the  security policy on the processes within a container by specifying an alternate type for the
       container. For example, run a container that is only allowed to listen on Apache ports by  executing  the
       following command:

       $ podman run --security-opt label=type:svirt_apache_t -i -t centos bash

       Note that an SELinux policy defining a svirt_apache_t type must be written.

       To mask additional specific paths in the container, specify the paths separated by a colon using the mask
       option with the --security-opt flag.

       $ podman run --security-opt mask=/foo/bar:/second/path fedora bash

       To  unmask  all  the  paths  that  are masked by default, set the unmask option to ALL. Or to only unmask
       specific paths, specify the paths as shown above with the mask option.

       $ podman run --security-opt unmask=ALL fedora bash

       To unmask all the paths that start with /proc, set the unmask option to /proc/*.

       $ podman run --security-opt unmask=/proc/* fedora bash

       $ podman run --security-opt unmask=/foo/bar:/sys/firmware fedora bash

   Setting device weight via --blkio-weight-device flag.
       $ podman run -it --blkio-weight-device "/dev/sda:200" ubuntu

   Using a podman container with input from a pipe
       $ echo "asdf" | podman run --rm -i --entrypoint /bin/cat someimage
       asdf

   Setting automatic user namespace separated containers
       # podman run --userns=auto:size=65536 ubi8-micro cat /proc/self/uid_map
       0 2147483647      65536
       # podman run --userns=auto:size=65536 ubi8-micro cat /proc/self/uid_map
       0 2147549183      65536

   Setting Namespaced Kernel Parameters (Sysctls)
       The --sysctl sets namespaced kernel parameters (sysctls) in the container. For example,  to  turn  on  IP
       forwarding in the containers network namespace, run this command:

       $ podman run --sysctl net.ipv4.ip_forward=1 someimage

       Note  that not all sysctls are namespaced. Podman does not support changing sysctls inside of a container
       that also modify the host system. As the kernel evolves we expect to see more sysctls become namespaced.

       See the definition of the --sysctl option above for the current list of supported sysctls.

   Set UID/GID mapping in a new user namespace
       Running a container in a new user namespace requires a mapping of the UIDs and GIDs from the host.

       $ podman run --uidmap 0:30000:7000 --gidmap 0:30000:7000 fedora echo hello

   Configuring Storage Options from the command line
       Podman allows for the configuration of storage by changing the values in the  /etc/container/storage.conf
       or by using global options. This shows how to set up and use fuse-overlayfs for a one-time run of busybox
       using global options.

       podman --log-level=debug --storage-driver overlay --storage-opt "overlay.mount_program=/usr/bin/fuse-overlayfs" run busybox /bin/sh

   Configure timezone in a container
       $ podman run --tz=local alpine date
       $ podman run --tz=Asia/Shanghai alpine date
       $ podman run --tz=US/Eastern alpine date

   Adding dependency containers
       The  first container, container1, is not started initially, but must be running before container2 starts.
       The podman run command starts the container automatically before starting container2.

       $ podman create --name container1 -t -i fedora bash
       $ podman run --name container2 --requires container1 -t -i fedora bash

       Multiple containers can be required.

       $ podman create --name container1 -t -i fedora bash
       $ podman create --name container2 -t -i fedora bash
       $ podman run --name container3 --requires container1,container2 -t -i fedora bash

   Configure keep supplemental groups for access to volume
       $ podman run -v /var/lib/design:/var/lib/design --group-add keep-groups ubi8

   Configure execution domain for containers using personality flag
       $ podman run --name container1 --personality=LINUX32 fedora bash

   Run a container with external rootfs mounted as an overlay
       $ podman run --name container1 --rootfs /path/to/rootfs:O bash

   Handling Timezones in java applications in a container.
       In order to use a timezone other than UTC when running a Java application  within  a  container,  the  TZ
       environment  variable  must be set within the container. Java applications ignores the value set with the
       --tz option.

       # Example run
       podman run -ti --rm  -e TZ=EST mytzimage
       lrwxrwxrwx. 1 root root 29 Nov  3 08:51 /etc/localtime -> ../usr/share/zoneinfo/Etc/UTC
       Now with default timezone:
       Fri Nov 19 18:10:55 EST 2021
       Java default sees the following timezone:
       2021-11-19T18:10:55.651130-05:00
       Forcing UTC:
       Fri Nov 19 23:10:55 UTC 2021

   Run a container connected to two networks (called net1 and net2) with a static ip
       $ podman run --network net1:ip=10.89.1.5 --network net2:ip=10.89.10.10 alpine ip addr

   Rootless Containers
       Podman runs as a non-root user on most systems. This feature  requires  that  a  new  enough  version  of
       shadow-utils  be  installed.  The  shadow-utils  package  must  include the newuidmap(1) and newgidmap(1)
       executables.

       In order for users to run rootless, there must  be  an  entry  for  their  username  in  /etc/subuid  and
       /etc/subgid which lists the UIDs for their user namespace.

       Rootless  Podman  works  better  if the fuse-overlayfs and slirp4netns packages are installed.  The fuse-
       overlayfs package provides a userspace overlay storage driver,  otherwise  users  need  to  use  the  vfs
       storage driver, which can be disk space expensive and less performant than other drivers.

       To  enable  VPN  on the container, slirp4netns or pasta needs to be specified; without either, containers
       need to be run with the --network=host flag.

ENVIRONMENT

       Environment variables within containers can be set using multiple different  options,  in  the  following
       order of precedence (later entries override earlier entries):

              • Container image: Any environment variables specified in the container image.

              • --http-proxy:  By  default,  several  environment variables are passed in from the host, such as
                http_proxy and no_proxy. See --http-proxy for details.

              • --env-host: Host environment of the process executing Podman is added.

              • --env-file: Any environment variables specified via env-files. If multiple files are  specified,
                then they override each other in order of entry.

              • --env: Any environment variables specified overrides previous settings.

       Run containers and set the environment ending with a *.  The trailing * glob functionality is only active
       when no value is specified:

       $ export ENV1=a
       $ podman run --env 'ENV*' alpine env | grep ENV
       ENV1=a
       $ podman run --env 'ENV*=b' alpine env | grep ENV
       ENV*=b

CONMON

       When  Podman  starts  a  container  it  actually executes the conmon program, which then executes the OCI
       Runtime.  Conmon is the container monitor.  It is a small program whose  job  is  to  watch  the  primary
       process  of  the container, and if the container dies, save the exit code.  It also holds open the tty of
       the container, so that it can be attached to later. This is what allows Podman to run  in  detached  mode
       (backgrounded), so Podman can exit but conmon continues to run.  Each container has their own instance of
       conmon.  Conmon  waits  for  the  container to exit, gathers and saves the exit code, and then launches a
       Podman process to complete the container cleanup, by shutting down the network and  storage.    For  more
       information about conmon, see the conmon(8) man page.

FILES

       /etc/subuid

       /etc/subgid

       NOTE:  Use  the  environment  variable  TMPDIR  to  change  the  temporary storage location of downloaded
       container images. Podman defaults to use /var/tmp.

HISTORY

       September 2018, updated by Kunal Kushwaha <kushwaha_kunal_v7@lab.ntt.co.jp>

       October 2017, converted from Docker documentation to Podman by Dan Walsh for Podman <dwalsh@redhat.com>

       November 2015, updated by Sally O'Malley <somalley@redhat.com>

       June 2014, updated by Sven Dowideit <SvenDowideit@home.org.au>

       April 2014, Originally compiled by William Henry <whenry@redhat.com> based on docker.com source  material
       and internal work.

FOOTNOTES

       1:  The  Podman  project  is  committed to inclusivity, a core value of open source. The master and slave
       mount propagation terminology used here is problematic and divisive, and needs to  be  changed.  However,
       these  terms  are  currently  used  within the Linux kernel and must be used as-is at this time. When the
       kernel maintainers rectify this usage, Podman will follow suit immediately.

                                                                                                   podman-run(1)

NAME

SYNOPSIS

DESCRIPTION

IMAGE

OPTIONS

Exit Status

EXAMPLES

ENVIRONMENT

CONMON

FILES

SEE ALSO

HISTORY

FOOTNOTES