Azure DevOps - Atlantis autoplan is triggered again when pull request is approved

[amasover]

Whenever there's a new approval on a pull request in ADO, Atlantis autoplan will be triggered, even though there's no new commit:

2020/03/13 18:45:16+0000 [INFO] server: POST /events – from 127.0.0.1:44580
2020/03/13 18:45:16+0000 [INFO] server: POST /events – respond HTTP 200
2020/03/13 18:46:13+0000 [INFO] server: POST /events – from 127.0.0.1:44580
2020/03/13 18:46:13+0000 [INFO] server: Identified event as type "updated"
2020/03/13 18:46:13+0000 [INFO] server: Executing autoplan
2020/03/13 18:46:13+0000 [INFO] server: POST /events – respond HTTP 200
2020/03/13 18:46:14+0000 [INFO] my/repo#145: Successfully parsed atlantis.yaml file
2020/03/13 18:46:14+0000 [INFO] my/repo#145: 1 projects are to be planned based on their when_modified config

This seems unexpected behavior to me. Sometimes the new plan happens when we already have a valid plan, or when somebody approves a PR after the apply has already happened (but before it is merged). If the behavior is intended, then we should maybe have an option to configure it.

It seems I can disable this behavior by setting the webhook to filter change as only "Source Branch Updated". But if I do that, then I think wouldn't be able to turn on "require approvals" in Atlantis?

BTW it looks like there was some somewhat related discussion already on @mcdafydd 's original PR to add Azure DevOps support.

[mcdafydd]

Thanks, @amasover! I have seen this behavior and will dig into it soon.

[mcdafydd]

I'll have a bit of time to work on this today.