Ubuntu Manpage: podman-pod-create

NAME

       podman-pod-create - Create a new pod

SYNOPSIS

       podman pod create [options] [name]

DESCRIPTION

       Creates an empty pod, or unit of multiple containers, and prepares it to have containers added to it. The
       pod can be created with a specific name. If a name is not given a random name is generated. The pod ID is
       printed  to  STDOUT.  You can then use podman create --pod <pod_id|pod_name> ... to add containers to the
       pod, and podman pod start <pod_id|pod_name> to start the pod.

       The    operator    can    identify    a    pod    in     three     ways:     UUID     long     identifier
       (“f78375b1c487e03c9438c729345e54db9d20cfa2ac1fc3494b6eb60872e74778”)      UUID      short      identifier
       (“f78375b1c487”) Name (“jonah”)

       podman generates a UUID for each pod, and if a name is not assigned to the container with --name  then  a
       random string name is generated for it. This name is useful to identify a pod.

       Note:  resource  limit related flags work by setting the limits explicitly in the pod's cgroup parent for
       all containers joining the pod. A container can override the resource limits when  joining  a  pod.   For
       example,  if  a  pod  was  created  via  podman  pod  create --cpus=5, specifying podman container create
       --pod=<pod_id|pod_name> --cpus=4 causes the container to use the smaller limit.  Also,  containers  which
       specify their own cgroup, such as --cgroupns=host, do NOT get the assigned pod level cgroup resources.

OPTIONS

--add-host=hostname[;hostname[;...]]:ip
Add a custom host-to-IP mapping to the pod's /etc/hosts file.

The option takes one or multiple semicolon-separated hostnames to be mapped to a single IPv4 or IPv6
address, separated by a colon. It can also be used to overwrite the IP addresses of hostnames Podman adds
to /etc/hosts by default (also see the --name and --hostname options). This option can be specified
multiple times to add additional mappings to /etc/hosts. It conflicts with the --no-hosts option and
conflicts with no_hosts=true in containers.conf.

Instead of an IP address, the special flag host-gateway can be given. This resolves to an IP address the
container can use to connect to the host. The IP address chosen depends on your network setup, thus
there's no guarantee that Podman can determine the host-gateway address automatically, which will then
cause Podman to fail with an error message. You can overwrite this IP address using the
host_containers_internal_ip option in containers.conf.

The host-gateway address is also used by Podman to automatically add the host.containers.internal and
host.docker.internal hostnames to /etc/hosts. You can prevent that by either giving the --no-hosts
option, or by setting host_containers_internal_ip="none" in containers.conf. If no host-gateway address
was configured manually and Podman fails to determine the IP address automatically, Podman will silently
skip adding these internal hostnames to /etc/hosts. If Podman is running in a virtual machine using
podman machine (this includes Mac and Windows hosts), Podman will silently skip adding the internal
hostnames to /etc/hosts, unless an IP address was configured manually; the internal hostnames are
resolved by the gvproxy DNS resolver instead.

Podman will use the /etc/hosts file of the host as a basis by default, i.e. any hostname present in this
file will also be present in the /etc/hosts file of the container. A different base file can be
configured using the base_hosts_file config in containers.conf.

The /etc/hosts file is shared between all containers in the pod.

--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.

--cgroup-parent=path
Path to cgroups under which the cgroup for the pod 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.

--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 │
└─────┴───────────┴─────┴──────────────┘

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.

--cpus=amount
Set the total number of CPUs delegated to the pod. Default is 0.000 which indicates that there is no
limit on computation power.

--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.

--device=host-device[:container-device][:permissions]
Add a host device to the pod. 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 pod 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: the pod implements devices by storing the initial configuration passed by the user and recreating
the device on each container added to the pod.

--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-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.

--dns=ipaddr
Set custom DNS servers in the /etc/resolv.conf file that is shared between all containers in the pod. A
special option, "none" is allowed which disables creation of /etc/resolv.conf for the pod.

--dns-option=option
Set custom DNS options in the /etc/resolv.conf file that is shared between all containers in the pod.

--dns-search=domain
Set custom DNS search domains in the /etc/resolv.conf file that is shared between all containers in the
pod.

--exit-policy=continue | stop
Set the exit policy of the pod when the last container exits. Supported policies are:

┌─────────────┬───────────────────────────────────────┐
│ Exit Policy │ Description │
├─────────────┼───────────────────────────────────────┤
│ continue │ The pod continues running, by keeping │
│ │ its infra container alive, when the │
│ │ last container exits. Used by │
│ │ default. │
├─────────────┼───────────────────────────────────────┤
│ stop │ The pod (including its infra │
│ │ container) is stopped when the last │
│ │ container exits. Used in kube play. │
└─────────────┴───────────────────────────────────────┘

--gidmap=pod_gid:host_gid:amount
GID map for the user namespace. Using this flag runs all containers in the pod with user namespace
enabled. It conflicts with the --userns and --subgidname flags.

--gpus=ENTRY
GPU devices to add to the container ('all' to pass all GPUs) Currently only Nvidia devices are supported.

--help, -h
Print usage statement.

--hostname=name
Set the pod's hostname inside all containers.

The given hostname is also added to the /etc/hosts file using the container's primary IP address (also
see the --add-host option).

--hosts-file=path | none | image
Base file to create the /etc/hosts file inside the container. This must either be an absolute path to a
file on the host system, or one of the following special flags:
"" Follow the base_hosts_file configuration in containers.conf (the default)
none Do not use a base file (i.e. start with an empty file)
image Use the container image's /etc/hosts file as base file

--infra
Create an infra container and associate it with the pod. An infra container is a lightweight container
used to coordinate the shared kernel namespace of a pod. Default: true.

--infra-command=command
The command that is run to start the infra container. Default: "/pause".

--infra-conmon-pidfile=file
Write the pid of the infra container's conmon process to a file. As conmon runs in a separate process
than Podman, this is necessary when using systemd to manage Podman containers and pods.

--infra-image=image
The custom image that is used for the infra container. Unless specified, Podman builds a custom local
image which does not require pulling down an image.

--infra-name=name
The name that is used for the pod's infra container.

--ip=ipv4
Specify a static IPv4 address for the pod, for example 10.88.64.128. This option can only be used if the
pod is joined to only a single network - i.e., --network=network-name is used at most once - and if the
pod 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 pod, 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 pod, for example fd46:db93:aa76:ac37::10. This option can only be
used if the pod is joined to only a single network - i.e., --network=network-name is used at most once -
and if the pod 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 pod, set multiple networks using the --network option with
a static IPv6 address specified for each using the ip6 mode for that option.

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

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

--mac-address=address
Pod network interface MAC address (e.g. 92:d0:c6:0a:29:33) This option can only be used if the pod is
joined to only a single network - i.e., --network=network-name is used at most once - and if the pod 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 pod, 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-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.

--name, -n=name
Assign a name to the pod.

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

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.

• ip6=IPv6: Specify a static IPv6 address for this container.

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

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

• host_interface_name=name: Specify a name for the created network interface outside the
container.

Any other options will be passed through to netavark without validation. This can be useful to
pass arguments to netavark plugins.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. 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 comma-separated networks 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. 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 the default for rootless containers and 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

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

--network-alias=alias
Add a network-scoped alias for the pod, 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 pod only has access to aliases on the first network that it joins. This limitation does not exist
with netavark/aardvark-dns.

--no-hostname
Do not create the /etc/hostname file in the containers.

By default, Podman manages the /etc/hostname file, adding the container's own hostname. When the --no-
hostname option is set, the image's /etc/hostname will be preserved unmodified if it exists.

--no-hosts
Do not modify the /etc/hosts file in the pod.

Podman assumes control over the pod's /etc/hosts file by default and adds entries for the container's
name (see --name option) and hostname (see --hostname option), the internal host.containers.internal and
host.docker.internal hosts, as well as any hostname added using the --add-host option. Refer to the
--add-host option for details. Passing --no-hosts disables this, so that the image's /etc/hosts file is
kept unmodified. The same can be achieved globally by setting no_hosts=true in containers.conf.

This option conflicts with --add-host.

--pid=pid
Set the PID mode for the pod. The default is to create a private PID namespace for the pod. Requires the
PID namespace to be shared via --share.

host: use the host’s PID namespace for the pod
ns: join the specified PID namespace
private: create a new namespace for the pod (default)

--pod-id-file=path
Write the pod ID to the file.

--publish, -p=[[ip:][hostPort]:]containerPort[/protocol]
Publish a container's port, or range of ports, within this pod 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: You must not publish ports of containers in the pod individually, but only by the pod itself.

Note: This cannot be modified once the pod is created.

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

--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).

Default restart policy for all the containers in a pod.

--security-opt=option
Security Options

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

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

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

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

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

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

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

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

Note: Labeling can be disabled for all pods/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 containers within the pod.

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

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

• 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.

--share=namespace
A comma-separated list of kernel namespaces to share. If none or "" is specified, no namespaces are
shared, and the infra container is not created unless explicitly specified via --infra=true. The
namespaces to choose from are cgroup, ipc, net, pid, uts. If the option is prefixed with a "+", the
namespace is appended to the default list. Otherwise, it replaces the default list. Defaults match
Kubernetes default (ipc, net, uts)

--share-parent
This boolean determines whether or not all containers entering the pod use the pod as their cgroup
parent. The default value of this option is true. Use the --share option to share the cgroup namespace
rather than a cgroup parent in a pod.

Note: This option conflicts with the --share=cgroup option since that option sets the pod as the cgroup
parent but enters the container into the same cgroupNS as the infra container.

--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 pod. 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.

--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 for all containers in the pod.

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 the ipc namespace is not shared within the pod, the above sysctls are not allowed.

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

Note: if the network namespace is not shared within the pod, the above sysctls are not allowed.

--uidmap=container_uid:from_uid:amount
Run all containers in the pod in a new user namespace using the supplied 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.

--userns=mode
Set the user namespace mode for all the containers in a pod. It defaults to the PODMAN_USERNS environment
variable. An empty value ("") means user namespaces are disabled.

Rootless user --userns=Key mappings:

┌─────────┬───────────┬──────────────────────────────┐
│ Key │ Host User │ Container User │
├─────────┼───────────┼──────────────────────────────┤
│ "" │ $UID │ 0 (Default User account │
│ │ │ mapped to root user in │
│ │ │ 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.) │
├─────────┼───────────┼──────────────────────────────┤
│ auto │ $UID │ nil (Host User UID is not │
│ │ │ mapped into container.) │
├─────────┼───────────┼──────────────────────────────┤
│ nomap │ $UID │ nil (Host User UID is not │
│ │ │ mapped into container.) │
└─────────┴───────────┴──────────────────────────────┘

Valid mode values are:

• auto[:OPTIONS,...]: automatically create a namespace. It is possible to specify these options to
auto:

• 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 the size for the user
namespace.

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

• host: 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 (default).

• keep-id: creates a user namespace where the current rootless user's UID:GID are mapped to the
same values in the container. This option is not allowed for containers created by the root
user.

• 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.

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

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

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

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

--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 pod 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 one or more of:

• rw|ro

• z|Z

• [O]

• [U]

• [no]copy

• [no]dev

• [no]exec

• [no]suid

• [r]bind

• [r]shared|[r]slave|[r]private[r]unbindable [1] ⟨#Footnote1⟩

• 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 pod.

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 pod 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 pod,
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 pod.

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 pod.
Without a label, the security system might prevent the processes running inside the pod from using the
content. By default, Podman does not change the labels set by the OS.

To change a label in the pod 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 pods 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 pod can use a private volume. Note: all containers
within a pod share the same SELinux label. This means all containers within said pod can read/write
volumes shared into the container created with the :Z on any of one the containers. 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 pod. 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 pod. For
example if a user wanted to volume mount their entire home directory into a pod, they need to disable
SELinux separation.

$ podman pod create --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 pod 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 pod 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 pod 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 pod infra 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 pod or infra container to work.

Do not modify the source directory mounted into the pod 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 pod are not visible
on the host and vice versa. One can change this behavior by specifying a volume mount propagation
property. When a volume is shared, mounts done under that volume inside the pod are visible on host and
vice versa. Making a volume slave[1] ⟨#Footnote1⟩ enables only one-way mount propagation: mounts done on
the host under that volume are visible inside the container but not the other way around.

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 pod, use the rbind option. By default the
bind option is used, and submounts of the source directory is not mounted into the pod.

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 pod.

Mounting the volume with the nodev option means that no devices on the volume can be used by processes
within the pod. 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 pod
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
#.

--volumes-from=CONTAINER[:OPTIONS]
Mount volumes from the specified container(s). Used to share volumes between containers and pods. 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 pod. 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.

Labeling systems like SELinux require that proper labels are placed on volume content mounted into a pod.
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 pod 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 pod, then
the volume hides that data on the target.

EXAMPLES

       Create a named pod.

       $ podman pod create --name test

       Create a named pod.

       $ podman pod create mypod

       Create a pod without an infra container.

       $ podman pod create --infra=false

       Create a named pod with infra container command to run.

       $ podman pod create --infra-command /top toppod

       Create a pod with published ports on the host.

       $ podman pod create --publish 8443:443

       Create a pod with the specified network configuration.

       $ podman pod create --network slirp4netns:outbound_addr=127.0.0.1,allow_host_loopback=true

       Create a pod with the specified network.

       $ podman pod create --network pasta

       Create a pod on two networks.

       $ podman pod create --network net1:ip=10.89.1.5 --network net2:ip=10.89.10.10

HISTORY

       July 2018, Originally compiled by Peter Hunt pehunt@redhat.com ⟨mailto:pehunt@redhat.com⟩

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-pod-create(1)

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

EXAMPLES

SEE ALSO

HISTORY

FOOTNOTES