Stack PR workflow

Plural Stacks can trigger dry runs on PRs, giving users clear information about what infrastructure will change as a result. This will do two things:

• run a dry run that terminates at the equivalent of terraform plan for the relevant stack type
• post informative messages back to the PR to surface relevant details in Git.

To trigger a PR run, you'll need to follow a few conventions:

• the branch can have any name matching plrl/stacks/<stack-name>/.*
• You include text like Plural Stack: <stack-name> in the title or description of the PR

This will tie the PR to the stack and initiate the dry-run process.

Dependencies

There are a few dependencies to getting these working:

• You need to configure an SCM connection to whatever source control provider you're using. We currently support GitHub and GitLab, and are happy to support others on request.
• You need to configure a webhook against that SCM as well.

Both can be done in the UI.

Finally, you need to configure your stacks to use a given SCM connection, which can be done globally with: