Match the input values for artifact type to ones required by

gcr.io/cloud-builders/gcs-uploader:latest image.

Also add documentation on gcr.io/cloud-builders/gcs-uploader:latest
supports only Manifest.

examples/run/gcs-resource-spec-taskrun.yaml

@@ -24,6 +24,6 @@ spec:
           - name: location
             value: gs://build-crd-tests/rules_docker-master.zip
           - name: artifactType
-            value: archive
+            value: Archive
           - name: type
             value: build-gcs

pkg/apis/pipeline/v1alpha1/build_gcs_resource.go

@@ -36,11 +36,11 @@ type GCSArtifactType string
 
 const (
 	// GCSArchive indicates that resource should be fetched from a typical archive file.
-	GCSArchive GCSArtifactType = "archive"
+	GCSArchive GCSArtifactType = "Archive"
 
 	// GCSManifest indicates that resource should be fetched using a
 	// manifest-based protocol which enables incremental source upload.
-	GCSManifest GCSArtifactType = "manifest"
+	GCSManifest GCSArtifactType = "Manifest"
 
 	// EmptyArtifactType indicates, no artifact type is specified.
 	EmptyArtifactType = ""
@@ -167,6 +167,7 @@ func getArtifactType(val string) (GCSArtifactType, error) {
 	valid := []string{string(GCSArchive), string(GCSManifest)}
 	switch aType {
 	case GCSArchive:
+		return aType, nil
 	case GCSManifest:
 		return aType, nil
 	case EmptyArtifactType:

pkg/apis/pipeline/v1alpha1/build_gcs_resource_test.go

@@ -170,15 +170,15 @@ func Test_Valid_NewBuildGCSResource(t *testing.T) {
 				Value: "build-gcs",
 			}, {
 				Name:  "ArtifactType",
-				Value: "manifest",
+				Value: "Manifest",
 			}},
 		},
 	}
 	expectedGCSResource := &BuildGCSResource{
 		Name:         "build-gcs-resource",
 		Location:     "gs://fake-bucket",
 		Type:         PipelineResourceTypeStorage,
-		ArtifactType: "manifest",
+		ArtifactType: "Manifest",
 	}
 
 	r, err := NewBuildGCSResource(pr)
@@ -218,21 +218,21 @@ func Test_BuildGCSGetDownloadContainerSpec(t *testing.T) {
 			Name:           "gcs-valid",
 			Location:       "gs://some-bucket",
 			DestinationDir: "/workspace",
-			ArtifactType:   "archive",
+			ArtifactType:   "Archive",
 		},
 		wantContainers: []corev1.Container{
 			CreateDirContainer("gcs-valid", "/workspace"), {
 				Name:  "storage-fetch-gcs-valid",
 				Image: "gcr.io/cloud-builders/gcs-fetcher:latest",
-				Args: []string{"--type", "archive", "--location", "gs://some-bucket",
+				Args: []string{"--type", "Archive", "--location", "gs://some-bucket",
 					"--dest_dir", "/workspace"},
 			}},
 	}, {
 		name: "invalid no destination directory set",
 		resource: &BuildGCSResource{
 			Name:         "gcs-invalid",
 			Location:     "gs://some-bucket",
-			ArtifactType: "archive",
+			ArtifactType: "Archive",
 		},
 		wantErr: true,
 	}}
@@ -261,7 +261,7 @@ func Test_BuildGCSGetUploadContainerSpec(t *testing.T) {
 			Name:           "gcs-valid",
 			Location:       "gs://some-bucket/manifest.json",
 			DestinationDir: "/workspace",
-			ArtifactType:   "manifest",
+			ArtifactType:   "Manifest",
 		},
 		wantContainers: []corev1.Container{{
 			Name:  "storage-upload-gcs-valid",
@@ -272,7 +272,7 @@ func Test_BuildGCSGetUploadContainerSpec(t *testing.T) {
 		name: "invalid upload to protected buckets with single file",
 		resource: &BuildGCSResource{
 			Name:           "gcs-valid",
-			ArtifactType:   "archive",
+			ArtifactType:   "Archive",
 			Location:       "gs://some-bucket",
 			DestinationDir: "/workspace/results.tar",
 		},