feat(pubsub): support payload wrapping for push subs (#8292)

* feat(pubsub): support payload wrapping for push subs

* fix lint issues

* fix lint issues

.github/workflows/vet.sh

@@ -55,6 +55,7 @@ golint ./... 2>&1 | (
     grep -vE " executeStreamingSql(Min|Rnd)Time" |
     grep -vE " executeSql(Min|Rnd)Time" |
     grep -vE "pubsub\/pstest\/fake\.go.+should have comment or be unexported" |
+    grep -vE "pubsub\/subscription\.go.+ type name will be used as pubsub.PubsubWrapper by other packages" |
     grep -v "ClusterId" |
     grep -v "InstanceId" |
     grep -v "firestore.arrayUnion" |

pubsub/pstest/fake.go

@@ -498,6 +498,11 @@ func (s *GServer) CreateSubscription(_ context.Context, ps *pb.Subscription) (*p
 	}
 	if ps.PushConfig == nil {
 		ps.PushConfig = &pb.PushConfig{}
+	} else if ps.PushConfig.Wrapper == nil {
+		// Wrapper should default to PubsubWrapper.
+		ps.PushConfig.Wrapper = &pb.PushConfig_PubsubWrapper_{
+			PubsubWrapper: &pb.PushConfig_PubsubWrapper{},
+		}
 	}
 	// Consider any table set to mean the config is active.
 	// We don't convert nil config to empty like with PushConfig above

pubsub/pstest/fake_test.go

@@ -1543,6 +1543,9 @@ func TestSubscriptionPushPull(t *testing.T) {
 	// Create a push subscription.
 	pc := &pb.PushConfig{
 		PushEndpoint: "some-endpoint",
+		Wrapper: &pb.PushConfig_PubsubWrapper_{
+			PubsubWrapper: &pb.PushConfig_PubsubWrapper{},
+		},
 	}
 	got := mustCreateSubscription(ctx, t, sclient, &pb.Subscription{
 		AckDeadlineSeconds: minAckDeadlineSecs,

pubsub/subscription.go

@@ -148,6 +148,10 @@ type PushConfig struct {
 	// This field is optional and should be set only by users interested in
 	// authenticated push.
 	AuthenticationMethod AuthenticationMethod
+
+	// The format of the delivered message to the push endpoint is defined by
+	// the chosen wrapper. When unset, `PubsubWrapper` is used.
+	Wrapper Wrapper
 }
 
 func (pc *PushConfig) toProto() *pb.PushConfig {
@@ -165,12 +169,19 @@ func (pc *PushConfig) toProto() *pb.PushConfig {
 		default: // TODO: add others here when GAIC adds more definitions.
 		}
 	}
+	if w := pc.Wrapper; w != nil {
+		switch wt := w.(type) {
+		case *PubsubWrapper:
+			pbCfg.Wrapper = wt.toProto()
+		case *NoWrapper:
+			pbCfg.Wrapper = wt.toProto()
+		default:
+		}
+	}
 	return pbCfg
 }
 
-// AuthenticationMethod is used by push points to verify the source of push requests.
-// This interface defines fields that are part of a closed alpha that may not be accessible
-// to all users.
+// AuthenticationMethod is used by push subscriptions to verify the source of push requests.
 type AuthenticationMethod interface {
 	isAuthMethod() bool
 }
@@ -212,6 +223,49 @@ func (oidcToken *OIDCToken) toProto() *pb.PushConfig_OidcToken_ {
 	}
 }
 
+// Wrapper defines the format of message delivered to push endpoints.
+type Wrapper interface {
+	isWrapper() bool
+}
+
+// PubsubWrapper denotes sending the payload to the push endpoint in the form of the JSON
+// representation of a PubsubMessage
+// (https://cloud.google.com/pubsub/docs/reference/rpc/google.pubsub.v1#pubsubmessage).
+type PubsubWrapper struct{}
+
+var _ Wrapper = (*PubsubWrapper)(nil)
+
+func (p *PubsubWrapper) isWrapper() bool { return true }
+
+func (p *PubsubWrapper) toProto() *pb.PushConfig_PubsubWrapper_ {
+	if p == nil {
+		return nil
+	}
+	return &pb.PushConfig_PubsubWrapper_{
+		PubsubWrapper: &pb.PushConfig_PubsubWrapper{},
+	}
+}
+
+// NoWrapper denotes not wrapping the payload sent to the push endpoint.
+type NoWrapper struct {
+	WriteMetadata bool
+}
+
+var _ Wrapper = (*NoWrapper)(nil)
+
+func (n *NoWrapper) isWrapper() bool { return true }
+
+func (n *NoWrapper) toProto() *pb.PushConfig_NoWrapper_ {
+	if n == nil {
+		return nil
+	}
+	return &pb.PushConfig_NoWrapper_{
+		NoWrapper: &pb.PushConfig_NoWrapper{
+			WriteMetadata: n.WriteMetadata,
+		},
+	}
+}
+
 // BigQueryConfigState denotes the possible states for a BigQuery Subscription.
 type BigQueryConfigState int
 
@@ -648,6 +702,16 @@ func protoToPushConfig(pbPc *pb.PushConfig) *PushConfig {
 			}
 		}
 	}
+	if w := pbPc.Wrapper; w != nil {
+		switch wt := w.(type) {
+		case *pb.PushConfig_PubsubWrapper_:
+			pc.Wrapper = &PubsubWrapper{}
+		case *pb.PushConfig_NoWrapper_:
+			pc.Wrapper = &NoWrapper{
+				WriteMetadata: wt.NoWrapper.WriteMetadata,
+			}
+		}
+	}
 	return pc
 }
 

pubsub/subscription_test.go

@@ -154,7 +154,7 @@ func TestListTopicSubscriptions(t *testing.T) {
 
 const defaultRetentionDuration = 168 * time.Hour
 
-func TestUpdateSubscription(t *testing.T) {
+func TestSubscriptionConfig(t *testing.T) {
 	ctx := context.Background()
 	client, srv := newFake(t)
 	defer client.Close()
@@ -191,13 +191,14 @@ func TestUpdateSubscription(t *testing.T) {
 				ServiceAccountEmail: "foo@example.com",
 				Audience:            "client-12345",
 			},
+			Wrapper: &PubsubWrapper{},
 		},
 		EnableExactlyOnceDelivery: false,
 		State:                     SubscriptionStateActive,
 	}
 	opt := cmpopts.IgnoreUnexported(SubscriptionConfig{})
-	if !testutil.Equal(cfg, want, opt) {
-		t.Fatalf("\ngot  %+v\nwant %+v", cfg, want)
+	if diff := testutil.Diff(cfg, want, opt); diff != "" {
+		t.Fatalf("compare subscription config mismatch, -got, +want\n%s", diff)
 	}
 
 	got, err := sub.Update(ctx, SubscriptionConfigToUpdate{
@@ -206,10 +207,13 @@ func TestUpdateSubscription(t *testing.T) {
 		Labels:              map[string]string{"label": "value"},
 		ExpirationPolicy:    72 * time.Hour,
 		PushConfig: &PushConfig{
-			Endpoint: "https://example.com/push",
+			Endpoint: "https://example2.com/push",
 			AuthenticationMethod: &OIDCToken{
-				ServiceAccountEmail: "foo@example.com",
-				Audience:            "client-12345",
+				ServiceAccountEmail: "bar@example.com",
+				Audience:            "client-98765",
+			},
+			Wrapper: &NoWrapper{
+				WriteMetadata: true,
 			},
 		},
 		EnableExactlyOnceDelivery: true,
@@ -225,17 +229,20 @@ func TestUpdateSubscription(t *testing.T) {
 		Labels:              map[string]string{"label": "value"},
 		ExpirationPolicy:    72 * time.Hour,
 		PushConfig: PushConfig{
-			Endpoint: "https://example.com/push",
+			Endpoint: "https://example2.com/push",
 			AuthenticationMethod: &OIDCToken{
-				ServiceAccountEmail: "foo@example.com",
-				Audience:            "client-12345",
+				ServiceAccountEmail: "bar@example.com",
+				Audience:            "client-98765",
+			},
+			Wrapper: &NoWrapper{
+				WriteMetadata: true,
 			},
 		},
 		EnableExactlyOnceDelivery: true,
 		State:                     SubscriptionStateActive,
 	}
-	if !testutil.Equal(got, want, opt) {
-		t.Fatalf("\ngot  %+v\nwant %+v", got, want)
+	if diff := testutil.Diff(got, want, opt); diff != "" {
+		t.Fatalf("compare subscription config mismatch, -got, +want\n%s", diff)
 	}
 
 	got, err = sub.Update(ctx, SubscriptionConfigToUpdate{
@@ -247,8 +254,8 @@ func TestUpdateSubscription(t *testing.T) {
 	}
 	want.RetentionDuration = 2 * time.Hour
 	want.Labels = nil
-	if !testutil.Equal(got, want, opt) {
-		t.Fatalf("\ngot %+v\nwant %+v", got, want)
+	if diff := testutil.Diff(got, want, opt); diff != "" {
+		t.Fatalf("compare subscription config mismatch, -got, +want\n%s", diff)
 	}
 
 	_, err = sub.Update(ctx, SubscriptionConfigToUpdate{})
@@ -264,8 +271,8 @@ func TestUpdateSubscription(t *testing.T) {
 		t.Fatal(err)
 	}
 	want.ExpirationPolicy = time.Duration(0)
-	if !testutil.Equal(got, want, opt) {
-		t.Fatalf("\ngot %+v\nwant %+v", got, want)
+	if diff := testutil.Diff(got, want, opt); diff != "" {
+		t.Fatalf("compare subscription config mismatch, -got, +want\n%s", diff)
 	}
 }