Templates: Ansible vs progfiguration#

Ansible templates are based on jinja2. They provide a lot of power out of the box.

Progfiguration does not ship with such a powerful template engine, just string.Template from the Python standard library. (We do provide progfiguration.temple.Temple which uses {$} for variable substitution rather than the default $, which is a nicer fit for shell scripts. Using it is completely optional.)

string.Template templates used by progfiguration#

  • Require no third-party dependencies.

  • Cannot contain logic like if or for statements, or include other templates.

  • Require all variables to be passed in explicitly. It is always clear what variables are used by a template, and what their source is. (This is an intentional design decision; see Variables: Ansible vs progfiguration.)

The vanilla string.Template class is available in the standard library. We also provide a tiny subclass progfiguration.temple.Temple, which uses {$} for variable substitution rather than the default $, which is a nicer fit for shell scripts.

jinja2 templates used by Ansible#

  • Require a third-party dependency.

  • Can contain logic like if or for statements, and include other templates.

  • Can access variables from the environment, or from a file, or from a dictionary. It is easier to set variables, but also easier to accidentally use the wrong value.

Templates were one of the reasons I wanted to write progfiguration. When working with large Ansible repositories, I found it difficult to understand what variables were used by a template, and where they came from.