What is a Custom Task?

[jerop]

Today, a spec is considered a Custom Task when APIVersion and Kind are non-empty.

If a user sets apiVersion to "tekton.dev/v1beta1" and kind to "Task", a CustomRun will be created instead of a TaskRun.

apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: hello-world
spec:
  steps:
    - name: echo
      image: ubuntu
      command:
        - echo
      args:
        - "hello world"
---
apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
  generateName: pr-
spec:
  pipelineSpec:
    tasks:
      - name: greeting
        taskRef:
          apiVersion: tekton.dev/v1beta1
          kind: Task
          name: hello-world
---
apiVersion: tekton.dev/v1
kind: PipelineRun
metadata:
  name: pr-jphlt
spec:
  pipelineSpec:
    tasks:
    - name: greeting
      taskRef:
        apiVersion: tekton.dev/v1beta1
        kind: Task
        name: hello-world
status:
  childReferences:
  - apiVersion: tekton.dev/v1beta1
    kind: CustomRun
    name: pr-jphlt-greeting
    pipelineTaskName: greeting
  conditions:
  - lastTransitionTime: "2023-03-29T15:35:22Z"
    message: 'Tasks Completed: 0 (Failed: 0, Cancelled 0), Incomplete: 1, Skipped: 0'
    reason: Running
    status: Unknown
    type: Succeeded
  pipelineSpec:
    tasks:
    - name: greeting
      taskRef:
        apiVersion: tekton.dev/v1beta1
        kind: Task
        name: hello-world
---
apiVersion: tekton.dev/v1beta1
kind: CustomRun
metadata:
  name: pr-jphlt-greeting
  ownerReferences:
  - apiVersion: tekton.dev/v1beta1
    kind: PipelineRun
    name: pr-jphlt
spec:
  customRef:
    apiVersion: tekton.dev/v1beta1
    kind: Task
    name: hello-world

If a user sets apiVersion to "tekton.dev/v1beta1" and kind to "Pipeline", a CustomRun will be created instead of a PipelineRun. This behavior has been been useful for Pipelines in Pipelines Custom Task.

apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: hello-world
spec:
  steps:
    - name: echo
      image: ubuntu
      command:
        - echo
      args:
        - "hello world"
---
apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
  generateName: pr-
spec:
  pipelineSpec:
    tasks:
      - name: greeting
        taskRef:
          apiVersion: tekton.dev/v1beta1
          kind: Pipeline
          name: hello-world
---
apiVersion: tekton.dev/v1
kind: PipelineRun
metadata:
  name: pr-xfb2f
spec:
  pipelineSpec:
    tasks:
    - name: greeting
      taskRef:
        apiVersion: tekton.dev/v1beta1
        kind: Pipeline
        name: hello-world
status:
  childReferences:
  - apiVersion: tekton.dev/v1beta1
    kind: CustomRun
    name: pr-xfb2f-greeting
    pipelineTaskName: greeting
  conditions:
  - lastTransitionTime: "2023-03-29T15:43:29Z"
    message: 'Tasks Completed: 0 (Failed: 0, Cancelled 0), Incomplete: 1, Skipped: 0'
    reason: Running
    status: Unknown
    type: Succeeded
  pipelineSpec:
    tasks:
    - name: greeting
      taskRef:
        apiVersion: tekton.dev/v1beta1
        kind: Pipeline
        name: hello-world
---
apiVersion: tekton.dev/v1beta1
kind: CustomRun
metadata:
  name: pr-xfb2f-greeting
  ownerReferences:
  - apiVersion: tekton.dev/v1beta1
    kind: PipelineRun
    name: pr-xfb2f
spec:
  customRef:
    apiVersion: tekton.dev/v1beta1
    kind: Pipeline
    name: hello-world

This behavior was initially surprising to me when refactoring isCustomTask in #6447, but it made sense after looking into it more. Was wondering if it may be surprising to users, especially given that @lbernick also raised similar questions during review of #6447. Opened this issue to make this behavior known so that we can discuss whether we're okay with this or we want to make some changes.

cc @tektoncd/core-maintainers

[dibyom]

IMO, it's clever but I found it a bit confusing too

[Yongxuanzhang]

If apiVersion is only used for custom task, why don't we rename it to something like CustomApiVersion to avoid confusion?

[lbernick]

Note from @Yongxuanzhang: When we enabled custom tasks by default, users who were accidentally setting APIVersion for Tasks and ClusterTasks experienced a regression, which is that Custom tasks would be created instead of TaskRuns (#6682). The fix for these users is to remove APIVersion.

I'd like to find some way to make this less confusing; CustomAPIVersion could help with that as Yongxuan suggested, or maybe this could be a reason to explore the discussion in #6186 again?

[tekton-robot]

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[tekton-robot]

Stale issues rot after 30d of inactivity.
Mark the issue as fresh with /remove-lifecycle rotten with a justification.
Rotten issues close after an additional 30d of inactivity.
If this issue is safe to close now please do so with /close with a justification.
If this issue should be exempted, mark the issue as frozen with /lifecycle frozen with a justification.

/lifecycle rotten

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[tekton-robot]

Rotten issues close after 30d of inactivity.
Reopen the issue with /reopen with a justification.
Mark the issue as fresh with /remove-lifecycle rotten with a justification.
If this issue should be exempted, mark the issue as frozen with /lifecycle frozen with a justification.

/close

Send feedback to tektoncd/plumbing.

[tekton-robot]

@tekton-robot: Closing this issue.

In response to this:

Rotten issues close after 30d of inactivity.
Reopen the issue with /reopen with a justification.
Mark the issue as fresh with /remove-lifecycle rotten with a justification.
If this issue should be exempted, mark the issue as frozen with /lifecycle frozen with a justification.

/close

Send feedback to tektoncd/plumbing.

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