When using ${variable} in containerTemplate, it is not working

[piyush-garg]

Expected Behavior

Templating in containerTemplate should work.

Actual Behavior

Templating in containerTemplate is not working.

Steps to Reproduce the Problem

1. Create a Cluster resource.

apiVersion: tekton.dev/v1alpha1
kind: PipelineResource
metadata:
  name: cluster-details
spec:
  type: cluster
  params:
  - name: url
    value: " "
  - name: name
    value: " "
  - name: username
    value: " "
  - name: token
    value: " "
  - name: cadata
    value: " "

2. Create a task using cluster resource.

apiVersion: tekton.dev/v1alpha1
kind: Task
metadata:
  name: task-openshift-command-clusterresource
spec:
  containerTemplate:
    env:
      - name: "KUBECONFIG"
        value: "/workspace/${inputs.resources.clusterdetails.name}/kubeconfig"
  inputs:
    resources:
      - name: clusterdetails
        type: cluster
  steps:
    - name: foo
      image: ubuntu
      command:
        - /bin/bash
      args: ["-c", "env"]

3. Create task run for the task

apiVersion: tekton.dev/v1alpha1
kind: TaskRun
metadata:
  name: task-run-openshift-command-clusterresource
spec:
  taskRef:
    name: task-openshift-command-clusterresource
  inputs:
    resources:
      - name: clusterdetails
        resourceRef:
          name: cluster-details

4. Check the logs of the step, it will show something like

oc logs task-run-openshift-command-clusterresource-pod-4645e9 -c build-step-foo
KUBECONFIG=/workspace/${inputs.resources.clusterdetails.name}/kubeconfig

Additional Info

Tekton version v0.3.1

[abayer]

Interesting - this is actually an enhancement, not a bug, fwiw, since variable templating has to be explicitly enabled for a field. This raises a question though - variable templating can only be done on explicitly specified string fields, which in the case of steps (i.e., Containers, so the logic we could trivially reuse for containerTemplate) currently means Name, Image, Args, Env values, Command, and Name, MountPath, and SubPath for VolumeMounts. Do we want to try to do a more general approach that, say, traversed the Container for all string fields and all fields that are structs with their string fields, etc? cc @bobcatfish @vdemeester for your thoughts.

[bobcatfish]

Do we want to try to do a more general approach that, say, traversed the Container for all string fields and all fields that are structs with their string fields, etc?

Yeah, I'm into that! I think it's confusing to only be doing it for a few fields.

[abayer]

That's definitely doable, for sure.

[bobcatfish]

Note #982 is expanding the scope of values that can be templated, but not as broadly as we're suggesting here!

[vdemeester]

#1006 is in, this should be fixed 👼
/close

[tekton-robot]

@vdemeester: Closing this issue.

In response to this:

#1006 is in, this should be fixed 👼
/close

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