Better support for go submodules

[8tomat8]

Context:
We have a repository which has a structure similar to

- root module
-- pkgA submodule
-- pkgB submodule
-- etc...

root module has no go files.
Each pkg{A,B,...} module has code+tests and separate go.mod+go.sum+vendor files.

Issue:
On every PR we are running

jobs:
  test:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v1
    - uses: actions/setup-go@v1
      with:
        go-version: '1.15.x'
    - name: Run tests
      # Go into each folder in the repo and run tests 10 times with the race detector
      run: for d in ./*/ ; do (cd "$d" && go test -race -count 10 ./...); done

  golangci:
    name: lint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Install golangci-lint
        uses: golangci/golangci-lint-action@v0.2.0
        with:
          version: v1.26
          args: --modules-download-mode vendor --config ./.golangci.yml ./...

But it fails with ERRO Running error: context loading failed: no go files to analyze

Question:
Is there a way to use this action to run linter in all the folders but without creating separate jobs with a matrix?

[SVilgelm]

The workaround is creating a step for every project and using the working-directory parameter:

  golangci:
    name: lint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Check golangci-lint for pkgA
        uses: golangci/golangci-lint-action@v2.2.0
        with:
          version: v1.29
          working-directory: pkgA
          args: --modules-download-mode vendor --config ./.golangci.yml ./...
      - name: Check golangci-lint for pkgB
        uses: golangci/golangci-lint-action@v2.2.0
        with:
          version: v1.29
          working-directory: pkgB
          args: --modules-download-mode vendor --config ./.golangci.yml ./...

[8tomat8]

This is exactly what we are trying to avoid :)
The issue here that every step has to be manually added and devs will definitely forget to update it 🤷

[mrigankakb]

I am facing the same issue with my monorepo. Seems this is not an issue with the action implementation, but default behaviour of golangci-lint cmd. However, it will be really helpful to have this capability for this to be used seamlessly in a monorepo.

[torkelrogstad]

Here's a rather nice approach for doing this using the matrix property in your actions config: golangci/golangci-lint#828 (comment)

[ldez]

I added examples for Go workspace and the GitHub Action: https://github.com/golangci/golangci-lint-action?tab=readme-ov-file#how-to-use

[DavidS-ovm]

The matrix approach is very wasteful (assuming most cost is in setup and caches are up-to-date) and provides really poor UX in github actions:

It would be really great to have this integrated into the action proper and have linting run for each module in parallel. That way it would also make sense to chuck a bit more CPUs at the problem where also setup steps might benefit e.g. by using private runners with more cores.