Add Support for Commenting on PR with Affected Stacks

[osterman]

Describe the Feature

Atmos should support native GitHub integration to comment on a PR (or issue) with a markdown formatted comment of the affected stacks.

It should support creating or updating an existing comment based on a regex pattern (so it's stateless).

The markdown template should be a property of the atmos.yaml so it can be customized.

It should probably be a feature flag of atmos describe affected, so the affected stacks do not need to be recomputed. In other words, we still need the JSON output to work with other github actions.

Expected Behavior

atmos describe affected --output json --github-issue-id 123

The above command would output the affected stacks as JSON and comment on the GitHub Issue #123 with a markdown formatted comment. The repo and github org would default to what is in the .github/config file of the current working repository.

Use Case

• GitOps with GitHub Actions or general CI/CD would be easier to implement since comments would be posted
• Spacelift Rego policies can parse GitHub comments and only plan affected stacks

[mcalhoun]

Erik Osterman (Cloud Posse) (@osterman) Why add this as a feature to atmos? We're already outputting yaml/json and there is tons of prior art (github actions) that can post a comment...seems like unnecessary code for us to maintain unless I'm missing an important nuance.

[osterman]

This is not planned. It's job of the CI/CD implementation to make whatever comments are needed.