Prepare copy-workflow for setting up unified CI for JS repos

[galargh]

Description

Both dispath.yml and copy-workflow.yml have accumulated a fair share of go specific setup. In this PR I'm trying to generalise both of these workflows to enable setting up unified CI for JS repos.

Moving config JSONs to configs directory

With JS adoption we're expecting more JSON config files to be needed. I propose to store all the config JSON files in a designated configs directory so that they're easy to find. This also allows us to use matching patterns like configs/*.json in various places.

Specifying what files should be copied for particular configuration

I have decided to create defaults object with files array field inside each config JSON file. The files array defines what files should be copied for that particular workflow by default.

In dispatch workflow, each object from repositories array is mapped to the output of merging the defaults object with the repository object. Thanks to this, it is also possible to override the list of files to be copied on a per repository basis (or other fields that defaults might define):

{
  "defaults": { "files": ["a", "b", "c"] },
  "repositories": [
    { "target": "1", "description": "copy files a, b and c to repository 1" },
    { "target": "2", "files": ["a", "b"], "description": "copy only files a and b to repository 2" }
  ]
}

Having the list of files to be copied in the same file as the list of repositories makes it easier for repo owners to reason about the outcome of adding a repository to the repositories list.

Handling language specific setup in copy-workflow

I have moved go specific setup to copy-workflow-go action. The action is performed iff the target object passed to the copy-workflow has deploy_go field set to true. I have used this pattern to provide specific setup for targets that request deploy_versioning too.

It will also be applicable when we want to introduce more languages, like JS for example. We could just introduce new flags like deploy_monorepo_js, deploy_isomorphic_js, etc.

Testing

• successfully ran dispatch.yml workflow on testing branch: https://github.com/protocol/.github/actions/runs/1553727642
• successfully ran copy-workflow.yml workflow on testing branch: https://github.com/protocol/.github/actions/runs/1553730245
• got sync: update CI config files .github-test-target#33 automerged
• changed the order of repositories in configs/go.json and failed to commit those changes because pre-commit hook prevented it
• PR checks

[galargh]

Since this PR doesn't modify any workflows in the target repositories I propose merging it into the master branch.

Testing after the rebase

• dispatch workflow from testing branch: https://github.com/protocol/.github/actions/runs/1582674326
• deploy workflow from testing branch: https://github.com/protocol/.github/actions/runs/1582676014
• sync PR in .github-test-target: sync: update CI config files .github-test-target#34

[marten-seemann]

Nice one. This is a lot better than working with fake bools (strings).

[marten-seemann]

LGTM!