Enhance user-facing Condition/ContainerTerminated Reasons with backwards compatibility

[JeromeJu]

We have had use cases as specified in #7223 and #7396 that downstream users and Tekton providers would want to have more granular error reasons. As discussed at the API WG and #7390, the existing CRDs {Step, TaskRun, PipelineRun} rely on knative.dev/pkg/apis#Condition for conveying user-facing reasons.

However these Condition reasons are being relied on for our Pipeline For example, dashboard will rely on the error reason to determine the step status.

Blocked issues:
Surfacing of actual Termination Reason in Step Status
Surface TaskRun failure reason when Step or Pod fails
Make user-facing condition messages more granular as canonical error codes

Current workaround:
Option 1: Add a new provisional field in the CRDs for {Step, TaskRun, PipelineRun} Condition/ContainerTerminatedState status
Option 2: Add it to the condition/containerTerminated message

Future work plan:
With a major version bump, i.e. in v2alpha1, we would be able to change the Condition/ContainerTerminated Reason

co-authored with: @renzodavid9

[JeromeJu]

/assign @renzodavid9

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[renzodavid9]

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[renzodavid9]

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[JeromeJu]

Through offline discussion with @renzodavid9 , we've examined that it might not be a feasible way to create a new field in the pod container status to update the container termination reason since these are all knative rather than Tekton conditions.

	Pros	Cons	Example
Add a new field	More straightforward when for the transition to replace the condition Reasons during the next major version bump		#7545
Add to the condition status message	Easier to maintain	Users might not be aware of the change

[JeromeJu]

One other question is that are making changes to PipelineRunStatus Condition Reason and PipelineRunStatus Condition Reason also considered as breaking changes?

It looks like that Dashboard relies on the ConditionStatus on this to determine the completion of a PipelineRun (similarly for TaskRuns). Does this imply that the changes made to PipelineRunStatus/TaskRunStatus Reasons will not be breaking changes for Dashboard and others that consumes such status?

cc @AlanGreene @vdemeester @tektoncd/core-collaborators 🙏

[AlanGreene]

The Dashboard also uses the reason values in a number of places, so changes to these would be considered a breaking change. See response to similar question on another issue proposing changes to the reason values for steps: #7390 (comment)

Changes for PipelineRun and TaskRun would have similar issues.

Here are just a few examples of the Dashboard's current use of the reason field for PipelineRun and TaskRun:

• https://github.com/tektoncd/dashboard/blob/bd39f464faa0a44a0379afbfdf1a54371d132782/src/containers/TaskRun/TaskRun.jsx#L317
• https://github.com/tektoncd/dashboard/blob/bd39f464faa0a44a0379afbfdf1a54371d132782/packages/components/src/components/RunHeader/RunHeader.scss#L92
• https://github.com/tektoncd/dashboard/blob/bd39f464faa0a44a0379afbfdf1a54371d132782/packages/components/src/components/TaskTree/TaskTree.jsx#L66
• https://github.com/tektoncd/dashboard/blob/bd39f464faa0a44a0379afbfdf1a54371d132782/packages/components/src/components/StatusIcon/StatusIcon.jsx#L65

[JeromeJu]

The Dashboard also uses the reason values in a number of places, so changes to these would be considered a breaking change. Changes for PipelineRun and TaskRun would have similar issues.

Thanks @AlanGreene for confirming the understanding on this 🙏
Would there also be a preference on the 2 options, adding a new field in PipelineRun/TaskRun status for enhancing via a new Reason field or adding the granular reasons into the Condition Status message?

[AlanGreene]

It depends on whether this information is only intended for user consumption or if it's also intended to be used by clients / automation.

If it's intended for clients I don't think the message is a good option. Today I believe most clients treat it as an opaque string and avoid parsing it. If we change this we would need to define a clear API contract for its structure, content, etc. and guard against unexpected changes.

[renzodavid9]

Following on #7539 (comment), and according with offline conversation with @JeromeJu , to avoid extending the ContainerStateTerminated from the k8s lib, we can instead modify the StepStatus from Tekton to add the new field. It will look something like this:

apiVersion: tekton.dev/v1
kind: TaskRun
metadata:
  name: task1
...
status:
  steps:
  - container: step-first
    imageID: docker-pullable://busybox@sha256:ba76950ac9eaa407512c9d859cea48114eeff8a6f12ebaa5d32ce79d4a017dd8
    name: first
    terminationReason: AnyReason # <- This will be the new field
    terminated:
      containerID: docker://aaa111222
      exitCode: 1
      finishedAt: "2024-01-08T16:27:38Z"
      reason: Error
      startedAt: "2024-01-08T16:27:38Z"

[JeromeJu]

Following on #7539 (comment), and according with offline conversation with @JeromeJu , to avoid extending the ContainerStateTerminated from the k8s lib, we can instead modify the StepStatus from Tekton to add the new field. It will look something like this:

apiVersion: tekton.dev/v1
kind: TaskRun
metadata:
  name: task1
...
status:
  steps:
  - container: step-first
    imageID: docker-pullable://busybox@sha256:ba76950ac9eaa407512c9d859cea48114eeff8a6f12ebaa5d32ce79d4a017dd8
    name: first
    terminationReason: AnyReason # <- This will be the new field
    terminated:
      containerID: docker://aaa111222
      exitCode: 1
      finishedAt: "2024-01-08T16:27:38Z"
      reason: Error
      startedAt: "2024-01-08T16:27:38Z"

Thansk @renzodavid9 for the discussion and this!
This looks like the way to go as consensus reached during the API WG 🙏

The next AI for us might be to create a PR RFC(requesting for feedback). i.e.

• RFC: Add FailureReason field for PipelineRun and TaskRun Status #7545

And we could together have some documentations in the deprecations md and elsewhere to claim our migration plan when moving to v2alpha1.