Page Comparison

General

• YAML files - All yaml files should use 2 space indents and end with .yml
• Variables - Use jinja variable syntax over deprecated variable syntax. {{ var }} not $var
• Use spaces around jinja variable names. {{ var }} not {{var}}
• Variables that are environment specific and that need to be overridden should be in ALL CAPS.
• Variables that are internal to the role should be lowercase.
• Prefix all variables defined in a role with the name of the role. Example: EDXAPP_FOO
• Keep roles self contained - Roles should avoid including tasks from other roles when possible
• Plays should do nothing more than include a list of roles except where pre_tasks and post_tasks are required (to manage a load balancer for example)
• Plays/Playbooks that apply to the general community should be copied to configuration/playbooks
• Plays/Playbooks that apply only to a specific organization (edx-east, edx-west) should be copied to a sub-directory under configuration/playbooks
• Tests - For automated integration tests use an included play named test.yml is included and run when a run_tests var is set to validate the role installation on a single instance.
• Deploys - For application updates include a deploy.yml with a list of tasks that start with service stop and end with a service start that is run to deploy an application update. Every task in deploy.yml should be tagged with deploy
• Nothing outside of tasks in deploy.yml should affect the application state
• All tasks in deploy.yml should be able to run as a user with limited sudo rule and not require root access.
• Handlers - Every role should have one or more handlers for restarting the service(s), for tasks that run in main.yml that require service restarts they/it will be notified.
• Separators - Use underscores (e.g. my_role) not dashes (my-role).
• Paths - When defining paths, do not include trailing slashes (e.g. my_path: /foo not my_path: /foo/. When concatenating paths, follow the same convention (e.g. {{ my_path }}/bar not {{ my_path }}bar)

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