Move several packages into internal

[lbernick]

Changes

This commit moves several packages in pkg/ into pkg/internal. This reduces the Pipelines API surface by ensuring these packages can't be imported and relied on by clients, as we only intend for pkg/apis and pkg/client to be imported outside of Pipelines. Other packages that contain exported functions used outside of pkg/ will be refactored in a later commit.

/kind cleanup

Submitter Checklist

As the author of this PR, please check off the items in this checklist:

• n/a Has Docs included if any changes are user facing
• n/a Has Tests included if any functionality added or changed
• Follows the commit message standard
• Meets the Tekton contributor standards (including
  functionality, content, code)
• Has a kind label. You can add one by adding a comment on this PR that contains /kind <type>. Valid types are bug, cleanup, design, documentation, feature, flake, misc, question, tep
• Release notes block below has been updated with any user facing changes (API changes, bug fixes, changes requiring upgrade notices or deprecation warnings)
• Release notes contains the string "action required" if the change requires additional action from users switching to the new release

Release Notes

Several packages have been moved into pkg/internal and can no longer be imported.

[lbernick]

part 1 of #5679

/assign @dibyom @vdemeester @wlynch

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/internal/artifacts/artifacts_storage.go	Do not exist	82.2%
pkg/internal/container/container_replacements.go	Do not exist	100.0%
pkg/internal/container/sidecar_replacements.go	Do not exist	100.0%
pkg/internal/container/step_replacements.go	Do not exist	70.0%
pkg/internal/list/diff.go	Do not exist	100.0%
pkg/internal/matrix/matrix.go	Do not exist	100.0%
pkg/internal/matrix/matrix_types.go	Do not exist	100.0%
pkg/internal/names/generate.go	Do not exist	100.0%
pkg/internal/pod/creds_init.go	Do not exist	93.9%
pkg/internal/pod/entrypoint.go	Do not exist	89.5%
pkg/internal/pod/entrypoint_lookup.go	Do not exist	86.4%
pkg/internal/pod/entrypoint_lookup_impl.go	Do not exist	75.0%
pkg/internal/pod/pod.go	Do not exist	89.5%
pkg/internal/pod/script.go	Do not exist	100.0%
pkg/internal/pod/status.go	Do not exist	90.9%
pkg/internal/pod/workingdir_init.go	Do not exist	92.9%
pkg/internal/status/status.go	Do not exist	89.2%
pkg/internal/substitution/substitution.go	Do not exist	63.0%
pkg/internal/workspace/apply.go	Do not exist	99.2%
pkg/internal/workspace/validate.go	Do not exist	100.0%

[tekton-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/internal/artifacts/artifacts_storage.go	Do not exist	81.9%
pkg/internal/container/container_replacements.go	Do not exist	100.0%
pkg/internal/container/sidecar_replacements.go	Do not exist	100.0%
pkg/internal/container/step_replacements.go	Do not exist	70.0%
pkg/internal/list/diff.go	Do not exist	100.0%
pkg/internal/matrix/matrix.go	Do not exist	100.0%
pkg/internal/matrix/matrix_types.go	Do not exist	100.0%
pkg/internal/pod/creds_init.go	Do not exist	93.9%
pkg/internal/pod/entrypoint.go	Do not exist	89.5%
pkg/internal/pod/entrypoint_lookup.go	Do not exist	86.4%
pkg/internal/pod/entrypoint_lookup_impl.go	Do not exist	75.0%
pkg/internal/pod/pod.go	Do not exist	89.5%
pkg/internal/pod/script.go	Do not exist	100.0%
pkg/internal/pod/status.go	Do not exist	90.9%
pkg/internal/pod/workingdir_init.go	Do not exist	92.9%
pkg/internal/status/status.go	Do not exist	89.2%
pkg/internal/substitution/substitution.go	Do not exist	63.0%
pkg/internal/workspace/apply.go	Do not exist	99.2%
pkg/internal/workspace/validate.go	Do not exist	100.0%

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
cmd/entrypoint/runner.go	84.4%	82.8%	-1.6
pkg/internal/artifacts/artifacts_storage.go	Do not exist	81.9%
pkg/internal/container/container_replacements.go	Do not exist	100.0%
pkg/internal/container/sidecar_replacements.go	Do not exist	100.0%
pkg/internal/container/step_replacements.go	Do not exist	70.0%
pkg/internal/list/diff.go	Do not exist	100.0%
pkg/internal/matrix/matrix.go	Do not exist	100.0%
pkg/internal/matrix/matrix_types.go	Do not exist	100.0%
pkg/internal/pod/creds_init.go	Do not exist	93.9%
pkg/internal/pod/entrypoint.go	Do not exist	89.5%
pkg/internal/pod/entrypoint_lookup.go	Do not exist	86.4%
pkg/internal/pod/entrypoint_lookup_impl.go	Do not exist	75.0%
pkg/internal/pod/pod.go	Do not exist	89.5%
pkg/internal/pod/script.go	Do not exist	100.0%
pkg/internal/pod/status.go	Do not exist	90.9%
pkg/internal/pod/workingdir_init.go	Do not exist	92.9%
pkg/internal/status/status.go	Do not exist	89.2%
pkg/internal/substitution/substitution.go	Do not exist	63.0%
pkg/internal/workspace/apply.go	Do not exist	99.2%
pkg/internal/workspace/validate.go	Do not exist	100.0%

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/internal/artifacts/artifacts_storage.go	Do not exist	81.9%
pkg/internal/container/container_replacements.go	Do not exist	100.0%
pkg/internal/container/sidecar_replacements.go	Do not exist	100.0%
pkg/internal/container/step_replacements.go	Do not exist	70.0%
pkg/internal/list/diff.go	Do not exist	100.0%
pkg/internal/matrix/matrix.go	Do not exist	100.0%
pkg/internal/matrix/matrix_types.go	Do not exist	100.0%
pkg/internal/pod/creds_init.go	Do not exist	93.9%
pkg/internal/pod/entrypoint.go	Do not exist	89.5%
pkg/internal/pod/entrypoint_lookup.go	Do not exist	86.4%
pkg/internal/pod/entrypoint_lookup_impl.go	Do not exist	75.0%
pkg/internal/pod/pod.go	Do not exist	89.5%
pkg/internal/pod/script.go	Do not exist	100.0%
pkg/internal/pod/status.go	Do not exist	90.9%
pkg/internal/pod/workingdir_init.go	Do not exist	92.9%
pkg/internal/status/status.go	Do not exist	89.2%
pkg/internal/substitution/substitution.go	Do not exist	63.0%
pkg/internal/workspace/apply.go	Do not exist	99.2%
pkg/internal/workspace/validate.go	Do not exist	100.0%

[vdemeester]

Note that today, other tektoncd component might depend on those, for example the cli, or the operator, or triggers or even chains. I think for each package we want to move we need to see if it make sense or not to be "public" (and exported) or not.

For example, github.com/tektoncd/pipeline/pkg/pod is used by results (tektoncd org) in experimental (notifiers and task-loops) and in buildkit-tekton (external, in my own repositories). In results the code that uses it looks like :

        case pod.ReasonCouldntGetTask, pod.ReasonFailedResolution, pod.ReasonFailedValidation, pod.ReasonExceededResourceQuota, pod.ReasonExceededNodeResources, pod.ReasonCreateContainerConfigError, pod.ReasonPodCreationFailed:
                return rpb.RecordSummary_FAILURE
        case pod.ReasonPending:
                return rpb.RecordSummary_UNKNOWN

Those "reason" do make sense to be public, maybe in another package or not, but they are definitely useful.
In buildkit-tekton, the code is more "involved", for example pod.IsContainerStep(c.Name), but it's still valuable to export this kind of functions. buildkit-tekton also uses github.com/tektoncd/pipeline/pkg/substitution (at least the exported ones) because it is useful to re-use (to be able to perform substitution à-la-tekton) and that package is also probably used in some custom task or resolvers I wrote.
github.com/tektoncd/pipeline/pkg/workspace is used in pipeline-in-pod for example. github.com/tektoncd/pipeline/pkg/list is used in triggers, in catlin, in results, in operator, in chains, in buildkit-tekton and in some resolvers I wrote as well.

[lbernick]

Thanks for pointing this out! This change was probably a bit too hasty. Is there a good way to find out which functions are in use by other projects? (I know we can look at package importers on pkg.go.dev, but doesn't tell us which functions/consts are in use.) Maybe a good place to start would be moving the reasons out of the pod package and into apis, and make the rest of the pod package internal? Going to close this out for now.

[vdemeester]

Is there a good way to find out which functions are in use by other projects? (I know we can look at package importers on pkg.go.dev, but doesn't tell us which functions/consts are in use.)

Not that I know of. Looking into package importers on pkg.go.dev helps us a bit at least.

Maybe a good place to start would be moving the reasons out of the pod package and into apis, and make the rest of the pod package internal?

I think it's gonna be both. There is probably a lot of things that needs to move in pkg/apis, and some in very specific, non internal package. I think we need to investigate and look into this as time goes.