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@ionos.com>