generator – Uses Jinja2 to construct hosts and groups from patterns

New in version 2.6.

Synopsis

  • Uses a YAML configuration file with a valid YAML or .config extension to define var expressions and group conditionals

  • Create a template pattern that describes each host, and then use independent configuration layers

  • Every element of every layer is combined to create a host for every layer combination

  • Parent groups can be defined with reference to hosts and other groups using the same template variables

Parameters

Parameter Choices/Defaults Configuration Comments
hosts
-
The name key is a template used to generate hostnames based on the layers option. Each variable in the name is expanded to create a cartesian product of all possible layer combinations.
The parents are a list of parent groups that the host belongs to. Each parent item contains a name key, again expanded from the template, and an optional parents key that lists its parents.
Parents can also contain vars, which is a dictionary of vars that is then always set for that variable. This can provide easy access to the group name. E.g set an application variable that is set to the value of the application layer name.
layers
-
A dictionary of layers, with the key being the layer name, used as a variable name in the host name and parents keys. Each layer value is a list of possible values for that layer.
plugin
- / required
    Choices:
  • generator
token that ensures this is a source file for the 'generator' plugin.

Examples

# inventory.config file in YAML format
plugin: generator
strict: False
hosts:
    name: "{{ operation }}-{{ application }}-{{ environment }}-runner"
    parents:
      - name: "{{ operation }}-{{ application }}-{{ environment }}"
        parents:
          - name: "{{ operation }}-{{ application }}"
            parents:
              - name: "{{ operation }}"
              - name: "{{ application }}"
          - name: "{{ application }}-{{ environment }}"
            parents:
              - name: "{{ application }}"
                vars:
                  application: "{{ application }}"
              - name: "{{ environment }}"
                vars:
                  environment: "{{ environment }}"
      - name: runner
layers:
    operation:
        - build
        - launch
    environment:
        - dev
        - test
        - prod
    application:
        - web
        - api

Status

Authors

  • UNKNOWN

Hint

If you notice any issues in this documentation, you can edit this document to improve it.

Hint

Configuration entries for each entry type have a low to high priority order. For example, a variable that is lower in the list will override a variable that is higher up.