Add metadata and configuration templates for publishing to BCR

[hharrisd]

References to other Issues or PRs

This PR is part of the work to publish grpc-gateway in BCR, described in this issue.

Have you read the Contributing Guidelines?

Yes

Brief description of what is fixed or changed

This PR seeks to add the required files for the publish-to-bcr plugin, which will publish the gRPC Gateway project as a module in the Bazel Central Registry.

The plugin aims to eliminate a manual publishing process for the module and initiate the process when a release is created.

The configuration consists of three files placed in the .bcr directory:

• .bcr/metadata.template.json: that describes the repository and maintainers' information.
• .bcr/presubmit.yml: describes the targets that will be built and tested on specific platforms and bazel versions to test the module.
• .bcr/source.template.json: that will automatically substitute values for the repository, owner, and tag based on the repository and release data.

The final result of this process is the creation of a PR in the BCR repository to publish the released version.

Other comments

Once this configuration is added to the repo, the publish-to-bcr should be configured as described here.

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CC: @AlejoAsd for awareness.

[johanbrandhorst]

Cool! Do we have a fork of the registry set up already or do you need me to fork it in the grpc-ecosystem org?

[johanbrandhorst]

How do we keep this list updated? We use dependabot and renovate to update our Bazel version generally (see #5277).

[iampat]

@hharrisd @johanbrandhorst
Thanks for working on this PR. I am very excited to have in the BCR. Please let me know if I can help to have grpc-gateway in BCR sooner. Thanks.

[johanbrandhorst]

I don't know what the status of this PR is, I asked Beto a question in my last comment, maybe he missed it?

[iampat]

If you and @hharrisd are ok, I can try answering your question on the PR.

[johanbrandhorst]

Sure, go for it.

[hharrisd]

Hi @johanbrandhorst, @iampat.

This PR is pending the test of the customManagers configuration in renovate.json.
One minor change is to add Johan's suggested OS to the platform list.

@iampat, if you can help us with that, you are welcome to do so.

One last comment: a few weeks ago, the functionality to publish to the module using GitHub Actions was added to Publish to BCR. We can still utilize either the plugin approach or the GH Action method.

[johanbrandhorst]

I think I'd be more comfortable using a Github Action than the Github App, as it will be more familiar and integrated with our existing CI system. Could you (@hharrisd) rewrite this to use the Action? If you are unable to help at this point, @iampat please create a new PR with the necessary changes.

[johanbrandhorst]

What's left to do here? It looks like it doesn't have the github action added yet?

[hharrisd]

What's left to do here? It looks like it doesn't have the github action added yet?

Hi @johanbrandhorst, I'm working on adapting the GitHub action. I expect to add this tomorrow.