Reduce image size

[nitrocode]

Community Note

• Please vote on this issue by adding a 👍 reaction to the original issue to help the community and maintainers prioritize this request. Searching for pre-existing feature requests helps us consolidate datapoints for identical requirements into a single place, thank you!
• Please do not leave "+1" or other comments that do not add relevant new information or questions, they generate extra noise for issue followers and do not help prioritize the request.
• If you are interested in working on this issue or have submitted a pull request, please leave a comment.

---

• I'd be willing to implement this feature (contributing guide)

Describe the user story

The image size is around 700MB which is pretty high for an alpine image. @jamengual and I dove in a vouple weeks ago to find that each terraform version installed is about 80MB. We currently download versions as old as 0.11.x all the way to 1.3.x.

Describe the solution you'd like

At the very least, remove the versions older than terraform 1.x

Describe the drawbacks of your solution

Existing users using atlantis with ancient versions will have to wait a small amount of time for newer versions of atlantis to download their needed terraform versions.

Describe alternatives you've considered

None