A closer look at the configuration created in the previous chapter reveals some parametrization: The file my-project-develop.yml contains a line that dynamically derives the name of an artifact from the project name (sample_output: {{ edi_configuration_name }}.result). Jinja2 will replace the expression {{ edi_configuration_name }} with the name of the configuration.

The following command can be used to display the dictionary that is available for Jinja2 operations when loading the configuration my-project-develop.yml:

edi image create --dictionary my-project-develop.yml

Since the dictionary is context sensitive to the sub-command you have to specify the full command with the additional option --dictionary to display the appropriate dictionary. The option --dictionary is available for all commands that deal with configuration.

my-project-develop.yml contains an even more complicated parametrization in the lxc_profiles section:

{% if edi_lxd_version is defined and (edi_lxd_version.split('.')[0] | int >= 3 or edi_lxd_version.split('.')[1] | int >= 9) %}
    path: lxc_profiles/general/default_root_device/default_root_device.yml
{% endif %}

This conditional code will make sure that an additional LXD profile gets generated and applied for recent LXD versions.

Plugins can even further benefit from Jinja2 since there are additional dictionary entries available. The option --plugins will output the details:

edi image create --plugins my-project-develop.yml

If supported for the plugin, edi will preview the plugin rendered by Jinja2 when using the above command. Given the plugin is an Ansible playbook, the whole plugin dictionary will be made available to the playbook by means of the Ansible command line option --extra-vars.