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
       templates 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
       order is relevant.

       ionit comes with an early boot one shot service that is executed  before  the  networking  service  which
       allows  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 <benjamin.drung@cloud.ionos.com>