Generate volume and volume mount names

[imjasonh]

Changes

Before this, if a user wanted to attach a Volume named "workspace"
they'd get a confusing error message (#1402). #1404 improves the error
message, but it would be nice to not have an error at all and just allow
user-defined volumes named "workspace"

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Release Notes

Implicit volume and volumeMount names are generated, allowing user-defined volume(mount)s named "workspace" and "home"

[tekton-robot]

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

File	Old Coverage	New Coverage	Delta
pkg/reconciler/taskrun/resources/pod.go	89.7%	90.0%	0.3

[abayer]

This would be a problem for Jenkins X - we count on the /workspace directory being named that, and users specify paths etc within /workspace in their jenkins-x.ymls. I would prefer that the default remains /workspace, with some way of overriding it to use dynamically-generated mounts.

[imjasonh]

I should clarify, the path /workspace is still provided, exactly as before. The name of that volume is changing from workspace to workspace-blahblah.

https://github.com/tektoncd/pipeline/pull/1405/files#diff-69ad715c7170f20be9430e47cc217bd3R104 still sets MountPath: workspaceDir (which is the const /workspace).

If JX depends on the name of the volume (not the path) being workspace then yeah we should not merge this. But I'd be curious why JX depends on the name of the volume and not just its path.

[abayer]

Aaah, OK. We definitely shouldn't be caring about the volume name, and I'm pretty sure we aren't. =)

[dibyom]

/lgtm

[dlorenc]

/approve

[tekton-robot]

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[vdemeester]

@imjasonh you got linted 😝

I1011 14:35:43.687] pkg/reconciler/taskrun/resources/pod.go:111:82: `makeCredentialInitializer` - `implicitVolumes` is unused (unparam)
I1011 14:35:43.688] func makeCredentialInitializer(credsImage, serviceAccountName, namespace string, implicitVolumes []corev1.Volume, implicitVolumeMounts []corev1.VolumeMount, kubeclient kubernetes.Interface) (*v1alpha1.Step, []corev1.Volume, error) {

[vdemeester]

ping @imjasonh
needs a rebase (and lint fix)

[tekton-robot]

New changes are detected. LGTM label has been removed.

[tekton-robot]

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

File	Old Coverage	New Coverage	Delta
pkg/reconciler/taskrun/resources/pod.go	89.5%	89.8%	0.3

[tekton-robot]

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

File	Old Coverage	New Coverage	Delta
pkg/reconciler/taskrun/resources/pod.go	89.5%	89.8%	0.3

[vdemeester]

@imjasonh still need a rebase 😅

[imjasonh]

Yeah I'm just going to abandon this in the face of #1605

[imjasonh]

I wonder whether a better way to handle this would be to explicitly reserve volume names starting with tekton-internal- or something, and reject user-specified conflicting volumes upfront.

Any objections?