Securing the master branch

[TomasTorsvik]

Hi @matsbn @annefou @JorgSchwinger ,
I think it would be a good idea to discuss (and implement) some security features for the master branch in the BLOM repository. I don't have access to these options myself in the central repository, I guess only @matsbn has as repository owner, but I see the available options in my own fork.

Security settings for branches are found by going to Settings -> Branches, and set "Branch name pattern" to "master".

Here is my suggestion for security settings:

• Require pull request reviews before merging --> ON
  • Require approving reviews: 1
  • Dismiss stale pull request approvals when new commits are pushed --> ON
    • I think this means that a new approved review must be made if there is a change in the pull request after the first approved review.
  • Require review from Code Owners: ??
    • At the moment I think @matsbn is the only "code owner", so this would imply that Mats should approve everything. Maybe this makes sense if there are more code owners.
• Require status checks to pass before merging --> OFF (for now)
  • We don't have any status checks for the repo. This is perhaps something we should look into?
• Require signed commits --> ??
  • I see that some of my commits (e.g. from my local PC to my fork) come up as "unsigned", while the things I commit directly to gitHub are marked "verified". I'm not sure if this is needed.
• Require linear history --> OFF
  • I think this is too restrictive.
• Include administrators --> ON?
  • This means that the security settings also applies to commits by administrators. I think this should be the normal procedure. If this is too restrictive at some time, it can perhaps be turned off temporarily.

Rules applied to everyone including administrators

• Allow force pushes --> OFF
• Allow deletions --> OFF
  • I think these things should only be allowed if something gets messed up very badly, and then it should only be turned on temporarily while the repo is fixed, probably in combination with temporary interaction limits.