Test GCS Tasks

Tasks in the catalog don't currently have a uniform approach
to testing. It would be good if the catalog provided some
kind of blessed path and supporting infrastructure so that
Tasks can be exercised as part of PRs.

This commit includes a test for the GCS tasks that utilizes
triggers to kick off a pipelinerun. There are still some decisions
to be made around how service account generation might work,
how the needed infra gets spun up, and how the triggers get
_triggered_ in the first place, but this demonstrates the
general idea.

coauthored with @sbwsg

gcs/sample/gcs-sample.yaml

@@ -0,0 +1,124 @@
+apiVersion: triggers.tekton.dev/v1alpha1
+kind: TriggerTemplate
+metadata:
+  name: gcs-triggertemplate
+spec:
+  params:
+    - name: pvc-name
+    - name: project-name
+    - name: secret-name
+  resourcetemplates:
+    - apiVersion: tekton.dev/v1beta1
+      kind: PipelineRun
+      metadata:
+        name: gcs-pr-$(uid)
+      spec:
+        workspaces:
+        - name: data
+          persistentVolumeClaim:
+            claimName: $(params.pvc-name)
+        - name: credentials
+          secret:
+            secretName: $(params.secret-name)
+        pipelineSpec:
+          workspaces:
+          - name: data
+          - name: credentials
+          tasks:
+          - name: gcs-create-bucket
+            taskRef:
+              name: gcs-create-bucket
+            workspaces:
+            - name: credentials
+              workspace: credentials
+            params:
+            - name: bucketName
+              value: gs://tekton-test-bucket-$(uid)
+            - name: project
+              value: $(params.project-name)
+          - name: create-data
+            runAfter: [gcs-create-bucket]
+            taskSpec:
+              workspaces:
+              - name: data
+              steps:
+              - name: write-data
+                image: ubuntu
+                script: |
+                  #!/usr/bin/env bash
+                  set -xe
+                  mkdir -p $(workspaces.data.path)/$(uid)/test_data/
+                  echo "Test data $(uid)" > $(workspaces.data.path)/$(uid)/test_data/test.txt
+            workspaces:
+            - name: data
+              workspace: data
+          - name: gcs-upload
+            taskRef:
+              name: gcs-upload
+            runAfter: [create-data]
+            workspaces:
+            - name: credentials
+              workspace: credentials
+            - name: source
+              workspace: data
+            params:
+            - name: path
+              value: $(uid)
+            - name: location
+              value: gs://tekton-test-bucket-$(uid)
+            - name: serviceAccountPath
+              value: service_account.json
+          - name: gcs-download
+            taskRef:
+              name: gcs-download
+            runAfter: [gcs-upload]
+            workspaces:
+            - name: credentials
+              workspace: credentials
+            - name: output
+              workspace: data
+            params:
+            - name: path
+              value: download-$(uid)
+            - name: location
+              value: gs://tekton-test-bucket-$(uid)
+            - name: typeDir
+              value: "true"
+            - name: serviceAccountPath
+              value: service_account.json
+          - name: verify-data
+            runAfter: [gcs-download]
+            workspaces:
+            - name: data
+              workspace: data
+            taskSpec:
+              workspaces:
+              - name: data
+              steps:
+              - image: ubuntu
+                script: |
+                  #!/usr/bin/env bash
+                  set -xe
+                  cat $(workspaces.data.path)/download-$(uid)/test_data/test.txt | grep "Test data $(uid)"
+          - name: delete-bucket
+            taskRef:
+              name: gcs-delete-bucket
+            runAfter: [gcs-download]
+            workspaces:
+            - name: credentials
+              workspace: credentials
+            params:
+            - name: bucketName
+              value: gs://tekton-test-bucket-$(uid)
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: gcs-test-storage
+spec:
+  resources:
+    requests:
+      storage: 16Mi
+  volumeMode: Filesystem
+  accessModes:
+    - ReadWriteOnce