Support Array and Strings for Matrix param validation

[nschad]

Hey,

Currently validation for the matrix alpha feature is partly done in this code:

func validateParametersInTaskMatrix(matrix *Matrix) (errs *apis.FieldError) {
	if matrix != nil {
		for _, param := range matrix.Params {
			if param.Value.Type != ParamTypeArray {
				errs = errs.Also(apis.ErrInvalidValue("parameters of type array only are allowed in matrix", "").ViaFieldKey("matrix", param.Name))
			}
		}
	}
	return errs
}

Unfortunately this doesn't yet support passing in Tekton Arrays as kubernetes type String as described here in TEP-0090

For example the following is not currently supported

tasks:
...
- name: task-5
  taskRef:
    name: task-5
  matrix:
  - name: values
    value: (tasks.task-4.results.foo) # array

Err:

for: "pipeline/pipeline-test.yaml": error when patching "pipeline/pipeline-test.yaml": admission webhook "validation.webhook.pipeline.tekton.dev" denied the request: validation failed: invalid value: parameters of type array only are allowed in matrix: spec.tasks[1].matrix[k8s-versions], spec.tasks[1].matrix[machine-versions]

Is that something that is being worked on?

[pritidesai]

What is the expectation here when array is empty? An empty array could mean 0 iterations (may be skip the entire task?) but what happens when matrix has multiple params specified and one of them is an empty array. This has to be considered while implementing this feature request.

[abayer]

I can tell you exactly what happens, thanks to #6056 (comment) - if one of the matrix params is an empty slice, everything breaks. =)

[pritidesai]

Yup, I thought so 🤣 while watching PR #6056, that's why raising this concern here 😄. Along with the way how we address such empty slice, its important to understand whether it's even possible for us to support it from the pipeline perspective.

[EmmaMunley]

/assign

[EmmaMunley]

This issue has been closed by this PR: #6516

[EmmaMunley]

/close

[tekton-robot]

@EmmaMunley: You can't close an active issue/PR unless you authored it or you are a collaborator.

In response to this:

/close

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[jerop]

Thank you @EmmaMunley!

[jerop]

Opened #6602 tracking support of array results