NAME

       ionit - Render configuration files from Jinja templates

SYNOPSIS

       ionit [OPTIONS]

DESCRIPTION

       ionit  is a simple and small configuration templating tool.  It collects a context and renders Jinja tem‐
       plates in a given directory.  The context can be either static JSON  or  YAML  files  or  dynamic  Python
       files.  Python files can also define functions passed through to the rendering.

       The  context filenames needs to end with .json for JSON, .py for Python, and .yaml for YAML.  The context
       files are read in alphabetical order.  If the same key is defined by multiple  context  files,  the  file
       that is read later takes precedence.  It is recommended to prefix the files with a number in case the or‐
       der is relevant.

       ionit  comes with an early boot one shot service that is executed before the networking service which al‐
       lows one to generate configurations files for the networking and other services before they are  started.
       In this regard, ionit can act as tiny stepbrother of cloud-init.

OPTIONS

       -c /path/to/config, –config /path/to/config
              Configuration directory containing context for rendering (default: /etc/ionit)

       -t /path/to/templates, –templates /path/to/templates
              Directory to search for Jinja templates (default: /etc)

       -e TEMPLATE_EXTENSION, –template-extension TEMPLATE_EXTENSION
              Extension to look for in template directory (default: jinja)

       –debug Print debug output

       -q, –quiet
              Decrease output verbosity to warnings and errors.

PYTHON MODULES

       Python  modules  can define a collect_context function.  This function is called by ionit and the current
       context is passed as parameter.  The current context can be used to derive more context information,  but
       this  variable  should not be modified.  collect_context must return a dictionary (can be empty) or raise
       an exception, which will be caught by ionit.

       Python modules can also define functions which can be called from the Jinja template on  rendering.   Use
       the ionit_plugin.function decorator to mark the functions to export.

       Note  that the functions names should not collide with other keys from the context.  If one Python module
       defines a function and a value in the context with the same name, the value  in  the  context  will  take
       precedence.

       An example Python module might look like:

              import ionit_plugin

              @ionit_plugin.function
              def double(value):
                  return 2 * value

              @ionit_plugin.function
              def example_function():
                  return "Lorem ipsum"

              def collect_context(current_context):
                  return {"key": "value"}

AUTHOR

       Benjamin Drung <bdrung@posteo.de>

ionit                                              2018-08-13                                           IONIT(1)