Refactor input resource volume handling to remove a type switch state…

…ment.

This change refactors the way input resources attach volumes to their steps.
Previously, there was a special-cased switch statement for Storage type resources.
This made the logic for resources hard to follow, and spread across the codebase. This
change refactors that by moving it up into the general Resource interface.

This is another follow-on to #1135

pkg/apis/pipeline/v1alpha1/build_gcs_resource.go

@@ -177,3 +177,7 @@ func getArtifactType(val string) (GCSArtifactType, error) {
 func (s *BuildGCSResource) GetUploadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
 	return getStorageUploadVolumeSpec(s, spec)
 }
+
+func (s *BuildGCSResource) GetDownloadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
+	return getStorageUploadVolumeSpec(s, spec)
+}

pkg/apis/pipeline/v1alpha1/cluster_resource.go

@@ -177,3 +177,7 @@ func (s *ClusterResource) GetDownloadContainerSpec() ([]corev1.Container, error)
 func (s *ClusterResource) GetUploadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
 	return nil, nil
 }
+
+func (s *ClusterResource) GetDownloadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
+	return nil, nil
+}

pkg/apis/pipeline/v1alpha1/gcs_resource.go

@@ -154,3 +154,7 @@ func (s *GCSResource) GetDownloadContainerSpec() ([]corev1.Container, error) {
 func (s *GCSResource) GetUploadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
 	return getStorageUploadVolumeSpec(s, spec)
 }
+
+func (s *GCSResource) GetDownloadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
+	return getStorageUploadVolumeSpec(s, spec)
+}

pkg/apis/pipeline/v1alpha1/git_resource.go

@@ -124,3 +124,7 @@ func (s *GitResource) GetUploadContainerSpec() ([]corev1.Container, error) {
 func (s *GitResource) GetUploadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
 	return nil, nil
 }
+
+func (s *GitResource) GetDownloadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
+	return nil, nil
+}

pkg/apis/pipeline/v1alpha1/image_resource.go

@@ -105,3 +105,7 @@ func (s ImageResource) String() string {
 func (s *ImageResource) GetUploadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
 	return nil, nil
 }
+
+func (s *ImageResource) GetDownloadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
+	return nil, nil
+}

pkg/apis/pipeline/v1alpha1/pull_request_resource.go

@@ -142,3 +142,7 @@ func (s *PullRequestResource) SetDestinationDirectory(dir string) {
 func (s *PullRequestResource) GetUploadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
 	return nil, nil
 }
+
+func (s *PullRequestResource) GetDownloadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error) {
+	return nil, nil
+}

pkg/apis/pipeline/v1alpha1/resource_types.go

@@ -56,6 +56,7 @@ type PipelineResourceInterface interface {
 	GetDownloadContainerSpec() ([]corev1.Container, error)
 	GetUploadContainerSpec() ([]corev1.Container, error)
 	GetUploadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error)
+	GetDownloadVolumeSpec(spec *TaskSpec) ([]corev1.Volume, error)
 	SetDestinationDirectory(string)
 }
 

pkg/reconciler/v1alpha1/taskrun/resources/input_resources.go

@@ -17,7 +17,6 @@ limitations under the License.
 package resources
 
 import (
-	"fmt"
 	"path/filepath"
 
 	"github.com/tektoncd/pipeline/pkg/apis/pipeline"
@@ -113,25 +112,13 @@ func AddInputResource(
 			taskSpec.Steps = append(copyStepsFromPrevTasks, taskSpec.Steps...)
 			taskSpec.Volumes = append(taskSpec.Volumes, as.GetSecretsVolumes()...)
 		} else {
-			switch resource.GetType() {
-			case v1alpha1.PipelineResourceTypeStorage:
-				{
-					storageResource, ok := resource.(v1alpha1.PipelineStorageResourceInterface)
-					if !ok {
-						return nil, xerrors.Errorf("task %q invalid gcs Pipeline Resource: %q", taskName, boundResource.ResourceRef.Name)
-					}
-					resourceContainers, resourceVolumes, err = addStorageFetchStep(taskSpec, storageResource)
-					if err != nil {
-						return nil, xerrors.Errorf("task %q invalid gcs Pipeline Resource download steps: %q: %w", taskName, boundResource.ResourceRef.Name, err)
-					}
-				}
-			default:
-				{
-					resourceContainers, err = resource.GetDownloadContainerSpec()
-					if err != nil {
-						return nil, xerrors.Errorf("task %q invalid resource download spec: %q; error %w", taskName, boundResource.ResourceRef.Name, err)
-					}
-				}
+			resourceContainers, err = resource.GetDownloadContainerSpec()
+			if err != nil {
+				return nil, xerrors.Errorf("task %q invalid resource download spec: %q; error %w", taskName, boundResource.ResourceRef.Name, err)
+			}
+			resourceVolumes, err = resource.GetDownloadVolumeSpec(taskSpec)
+			if err != nil {
+				return nil, xerrors.Errorf("task %q invalid resource download spec: %q; error %w", taskName, boundResource.ResourceRef.Name, err)
 			}
 
 			allResourceContainers = append(allResourceContainers, resourceContainers...)
@@ -146,38 +133,6 @@ func AddInputResource(
 	return taskSpec, nil
 }
 
-func addStorageFetchStep(taskSpec *v1alpha1.TaskSpec, storageResource v1alpha1.PipelineStorageResourceInterface) ([]corev1.Container, []corev1.Volume, error) {
-	gcsContainers, err := storageResource.GetDownloadContainerSpec()
-	if err != nil {
-		return nil, nil, err
-	}
-
-	var storageVol []corev1.Volume
-	mountedSecrets := map[string]string{}
-	for _, volume := range taskSpec.Volumes {
-		mountedSecrets[volume.Name] = ""
-	}
-
-	for _, secretParam := range storageResource.GetSecretParams() {
-		volName := fmt.Sprintf("volume-%s-%s", storageResource.GetName(), secretParam.SecretName)
-
-		gcsSecretVolume := corev1.Volume{
-			Name: volName,
-			VolumeSource: corev1.VolumeSource{
-				Secret: &corev1.SecretVolumeSource{
-					SecretName: secretParam.SecretName,
-				},
-			},
-		}
-
-		if _, ok := mountedSecrets[volName]; !ok {
-			storageVol = append(storageVol, gcsSecretVolume)
-			mountedSecrets[volName] = ""
-		}
-	}
-	return gcsContainers, storageVol, nil
-}
-
 func getResource(r *v1alpha1.TaskResourceBinding, getter GetResource) (*v1alpha1.PipelineResource, error) {
 	// Check both resource ref or resource Spec are not present. Taskrun webhook should catch this in validation error.
 	if r.ResourceRef.Name != "" && r.ResourceSpec != nil {