In tekton, how to set task resources in a pipeline definition?

I have a pipeline that references a task:

---
apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: foo
spec:
  tasks:
    - name: my-bar-task
      taskRef:
        name: bar-task
        bundle: ...

That task has resources:

---
apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: bar-task
spec:
  steps:
    - name: step-one
      resources:
        requests:
          memory: "1Gi"
          cpu: "1"
        limits:
          memory: "2Gi"
          cpu: "1"

I would like to be able to override the resources in the pipeline definition. Something like this:

---
apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: foo
spec:
  tasks:
    - name: my-bar-task
      taskRef:
        name: bar-task
        bundle: ...
        resources:
          requests:
            memory: "4Gi"
            cpu: "1"
          limits:
            memory: "5Gi"
            cpu: "1"

But when I tried that, the override was ignored. Is what I am trying possible? I know the resources can be overridden from a pipeline run but I am particularly wondering about doing that in a pipeline.

Solution

At the pipeline level: NO.

However this is possible, at the PipelineRun/TaskRun level.

ALTHOUGH, this is an alpha feature (not yet globally available / "stable"). Over time, it may graduate as a stable feature -- keeping in mind there could be breaking changes in that process. Afterwards, should be enabled by default.

Nowadays, you need to enable the corresponding alpha feature first (TEP-0094: specifying resource requirements at runtime)

Depending on where/how you installed Tekton, you should have some configmap, somewhere, like the following:

$ kubectl get cm -n tekton-pipelines -o yaml feature-flags
apiVersion: v1
data:
  ...
  enable-api-fields: alpha
  ...
kind: ConfigMap
metadata:
  name: feature-flags
  namespace: tekton-pipelines

Setting enable-api-fields: alpha should enable that feature in your installation.

Having done so, you would be able to override those values, in your PipelineRun. Eg:

apiVersion: tekton.dev/v1beta1
kind: PipelineRun
spec:
  taskRunSpecs:
  - pipelineTaskName: build
    stepOverrides:
    - name: build
      resources:
        limits:
          cpu: 200m
          memory: 768Mi
        requests:
          cpu: 100m
          memory: 512Mi
  pipelineRef:
    name: docker-build