Proposal: post GitHub plan comments with output as a gist

[dmathieu]

Hi,

Some of our changes generate quite large plan output (due to other issues with one of our Terraform providers), generating a lot of GitHub comments (up to 50), making the Pull Requests impossible to read.
Ideally, the plan output should be set as an attachment on the comment so it's not limited on size. But the GitHub API doesn't allow setting attachments programmatically.

So here is my proposal: instead of adding the output as text in the comment, create a secret gist for that output, and provide a link to it.
If this change is deemed reasonable, I'm happy to implement it. I'm also happy to hear any alternative.

[nitrocode]

@dmathieu Interesting idea. I think implementing the checks api on the bot would have more return since each plan would be its own clickable section.

#936

What do you think?

[nitrocode]

Closing this in favor of #936