"From" does not work

[vincent-pli]

Expected Behavior

This my pipeline:

apiVersion: tekton.dev/v1alpha1
kind: Pipeline
metadata:
  name: tutorial-pipeline
spec:
  resources:
    - name: source-repo
      type: git
    - name: docker-image
      type: image
  tasks:
    - name: build-model-image
      taskRef:
        name: build-docker-image-from-git-source
      params:
        - name: pathToDockerFile
          value: /workspace/docker-source/mnist/Dockerfile.model
        - name: pathToContext
          value: /workspace/docker-source/mnist/ #configure: may change according to your source
      resources:
        inputs:
          - name: docker-source
            resource: source-repo
        outputs:
          - name: docker-image
            resource: docker-image
    - name: train
      taskRef:
        name: train-model
      resources:
        inputs:
          - name: train-image
            from:
              - build-model-image

I guess it's right, just follow the guide, I expect the task will run as build-model-image -> train

Actual Behavior

I get error:
pipelineTask tried to use input resource not present in declared resources

Additional Info

I try to figure out what happened, then find the code in pkg/reconciler/v1alpha1/pipelinerun/resources/pipelinerunresolution.go

func getPipelineRunTaskResources(pt v1alpha1.PipelineTask, providedResources map[string]v1alpha1.PipelineResourceRef) ([]v1alpha1.TaskResourceBinding, []v1alpha1.TaskResourceBinding, error) {
	inputs, outputs := []v1alpha1.TaskResourceBinding{}, []v1alpha1.TaskResourceBinding{}
	if pt.Resources != nil {
		for _, taskInput := range pt.Resources.Inputs {
			// if len(taskInput.From) > 0 {
			// 	continue
			// }
			resource, ok := providedResources[taskInput.Resource]
			if !ok {
				return inputs, outputs, fmt.Errorf("pipelineTask tried to use input resource %s not present in declared resources", taskInput.Resource)
			}
			inputs = append(inputs, v1alpha1.TaskResourceBinding{
				Name:        taskInput.Name,
				ResourceRef: resource,
			})
		}
		for _, taskOutput := range pt.Resources.Outputs {
			resource, ok := providedResources[taskOutput.Resource]
			if !ok {
				return outputs, outputs, fmt.Errorf("pipelineTask tried to use output resource %s not present in declared resources", taskOutput.Resource)
			}
			outputs = append(outputs, v1alpha1.TaskResourceBinding{
				Name:        taskOutput.Name,
				ResourceRef: resource,
			})
		}
	}
	return inputs, outputs, nil
}

I don't know, the logic is not right, then I try to add additional code(the comment ones) and I get a memory error in
pkg/reconciler/v1alpha1/pipelinerun/resources/pipelinerunresolution.ValidateFrom

at the end, I pass the issue by add additional item in inputs section of the second task:
from:

      resources:
        inputs:
          - name: train-image
            from:
              - build-model-image

to:

      resources:
        inputs:
          - name: train-image
            resource: docker-image
            from:
              - build-model-image

So is this issue just a document error?

[vincent-pli]

@vdemeester
Could you take a look this?

[piyush-garg]

@vincent-pli Seems like a document issue. AFAIK, we need to provide resource filed which will be the resource name from the previous task, so your changed input resources for the second task looks fine to me. Can you please point me where the yaml's are.

More @vdemeester can give us info about this. Thanks

[vincent-pli]

Thanks @piyush-garg , I just follow document about pipelines:
https://github.com/tektoncd/pipeline/blob/master/docs/pipelines.md

[piyush-garg]

Ok, Thanks @vincent-pli will fix that.

For your reference, here is an example with the details I provided https://github.com/tektoncd/pipeline/blob/master/docs/tutorial.md#pipeline

@vdemeester Any thoughts.