Matrix support is broken, matrix is always invalid 😅

[vdemeester]

Expected Behavior

Given the following Pipeline (simple adaptation from the documentation), the Pipeline gets created.

apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: neo
spec:
  params:
  - name: persons
    type: array
    default:
    - Neo
    - Trinity
    - Morpheus
    - Tank
    - Switch
  - name: actions
    type: array
    default:
    - hello
    - bye
  tasks:
  - name: hello-people
    matrix:
    - name: person
      value: $(params.persons)
    - name: action
      value: $(params.actions)
    taskSpec:
      params:
      - name: person
        type: string
      - name: action
        type: string
      steps:
      - image: docker.io/library/bash:latest
        script: |
          echo $(params.action) $(params.person)

Actual Behavior

It fails with the following message:

Error from server (BadRequest): error when creating "matrix.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[0].matrix[action], spec.tasks[0].matrix[person]

Those parameters are of type array though.

Steps to Reproduce the Problem

1. Create the given Pipeline
2. What the error

Additional Info

• Kubernetes version:

  Output of kubectl version:

  Server Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.1", GitCommit:"5e58841cce77d4bc13713ad2b91fa0d961e69192", GitTreeState:"clean", BuildDate:"2021-05-21T23:01:33Z", GoVersion:"go1.16.4", Compiler:"gc", Platform:"linux/amd64"}
  

• Tekton Pipeline version:

  Output of tkn version or kubectl get pods -n tekton-pipelines -l app=tekton-pipelines-controller -o=jsonpath='{.items[0].metadata.labels.version}'

  devel (today's main branch)
  

[vdemeester]

ok actually, Matrix support is not fully implemented yet. The documentation state it's alpha and not fully functional, which is true. I think, in the future, we should try to add the documentatiton (at least in docs/, it could live elsewhere before…) and in the API at the last pull-requests submitted.

And maybe hide things behind buildflag or something when not ready. As of today, it's slightly confusing as we may think the feature is there (because the api changes are there in the API) when it's just not working at all 👼🏼 .

[vdemeester]

I am going to close this as almost all seems to be implemented, and tracked here