Provide option to configure format of branch name

[greysteil]

From @edkellena on January 9, 2018 15:40

Hey,
It would be super awesome if we could specify some format for the branch name created.

Use-case:
Our CI system sees a PR raised and will run through a build process that generates a Docker image and tags it with the branch name. Unfortunately Docker tags have more limited scope than Git branches...
A tag name must be valid ASCII and may contain lowercase and uppercase letters, digits, underscores, periods and dashes. A tag name may not start with a period or a dash and may contain a maximum of 128 characters.

The / in the Dependabot branches is causing that tagging to fail. We can work around this with some awk/shell wizardry I guess, but would be nice not to have to do this.

Copied from original issue: dependabot/feedback#72

[greysteil]

Thanks for the feedback @edkellena.

It's a totally legit request, but I'm not keen on changing things on Dependabot's side for a couple of reasons:

• branch name generation is already quite complicated and I don't want to add more considerations to it
• there's no obvious place to put the setting in the frontend at the moment

Do you have control over the build process on your side? I'm hoping it would be straightforward for you to sanitize the branch name when generating a tag.

[greysteil]

From @edkellena on January 9, 2018 22:12

Fair enough 👍 I did wonder whether it would be a fruitless ask! Would be happy to attempt a PR for the generation, but without the UI setting available, that would be a bit pointless.

I do have some very hacky workaround at the moment, which I'll try to unhack soon. Cheers though!

[greysteil]

Always worth asking! Thanks for understanding 🙂 .

[SanjiKir]

Is it still a problem to implement? We have exactly the same issue

[BobbyMcWho]

You could always monkey-patch it, now whether or not you should...

module Dependabot
  class PullRequestCreator
    class BranchNamer
      def new_branch_name
        super.gsub(TO_REMOVE, TO_REPLACE)
      end
    end
  end
end

[ritaly]

if you use dependabot v2 just add to your dependabot.yml

pull-request-branch-name:
      separator: "-"

https://docs.github.com/en/github/administering-a-repository/configuration-options-for-dependency-updates#pull-request-branch-nameseparator

[pavellishin]

I'd like to bump this request - our CI system also requires that branch names only be so long.

What we don't require is that our branch names be semantically accurate - something like dependabot_20210625.1544 would work just as well as a descriptive name, given that the pull request title and description, as well as the contents, are enough to go on.

I do understand that the logic in branch_namer is moderately complex, and it would be hard to set up some sort of way to provide a format string, but maybe a flag to toggle the type of branch name format? Or even an option to leave off certain parts (e.g., package manager) and/or truncate the whole thing (from the start or the end) to a given length?

Right now, a lot of our dependabot PRs are unusable without a dev having to manually create a new branch and PR.

[oliviasv]

Is there an option to change the branch name? I think it is too long, and maybe it would be better and cleaner for the branch to include only dependabot/updated-dependencies.

[jayoutdoorsy]

Why was this closed? The following dependabot branch breaks docker tags dependabot/npm_and_yarn/shelljs-0.8.5. I feel like the obvious fix would be to switch the branch naming convention to dependabot/npm_and_yarn/${lib_name}-${uuid.slice(0, 8)}. We will be forced to do this in our own code. There's already an option in the yaml file for pull_request_branch_name but the only sub-option is separator

I don't see why the version-number needs to be in the branch name. What's the purpose of that? In any case, it makes sense to make it an option to provide a custom branch name.

[luiscantero]

+1 for this request. Our dependabot build fail because we use ACR.
ACR requirements: Repository names can only include lowercase alphanumeric characters, periods, dashes, underscores, and forward slashes. Reference

Sample error from the pipeline:

Message: Image name 'dependabot/nuget/Moq-4.1/something/something:2.2.0-linux-amd64' is invalid. 
The acceptable patterns are 'repository' or 'repository:tag'.
The repository and tag names follow the standardized docker repository and tag naming conventions.
Tag templates are supported within '{{' and '}}'.