ansible-style-guide

Objective

This style guide is designed to ensure consistent style and practices across M-Lab's Ansible playbooks and associated Ansible files.

Style Guide Additions / Changes

To propose an addition or change to the style guide:

1. File a new issue
2. Give the other M-Lab Ansible developers a few days to reach agreement.
3. Make a pull request to implement the agreed upon change.

Style Guide Style

This style guide is modeled after Google Style guides, for example:

• Google Python Style Guide
• Google JavaScript Style Guide

In particular, style decisions should include both a clear explanation of the style choice and the rationale for the decision.

Relationship to Ansible Playbook Best Practices

This style guide is an extension of the Ansible Playbook Best Practices. If contradictions arise between the two documents, the Playbook Best Practices take priority and this style guide should be modified to eliminate the contradiction.

Ansible Language Rules

One parameter per line

Decision

Use line breaks and indentation to separate parameters to Ansible modules, for example:

# Correct
- name: create foo temp directory
  file: path=/tmp/foo
        state=directory
        owner=bar
        group=fooers

# WRONG
- name: create foo temp directory
  file: path=/tmp/foo
        state=directory owner=bar group=fooers # WRONG: multiple params on line

Pros

• One parameter per line is a simple rule to follow globally

Cons

• Takes up more vertical space in the file
• Not as easy to express tight grouping among related parameters (e.g. owner, group, mode for several modules)