feat: Add MKC Code Examples (#5359)

* feat: provide code examples for managedkafka
connect clusters and connectors

* Managed Kafka Connect Go Code Samples
* Adds fake client for testing Connect clusters

* Updated headers.

* Reset buffer for sub-tests.

* Align code samples with TF / Python / Java samples.

* Add comment about accessible subnets and DNS domains.

* Fix memory defaults for connect cluster example.

* Fix name of MM2 Source sample.

* Fix sample parameter for Cloud Storage Sink connector.

* Fix linting errors.

* Fix test error.

* Fix CreateBigQuerySinkConnector parameters.

---------

Co-authored-by: Katie McLaughlin <katie@glasnt.com>

Author: salmany

internal/managedkafka/fake/fake.go

@@ -30,9 +30,11 @@ import (
 )
 
 const (
-	clusterID       = "fake-cluster"
-	topicID         = "fake-topic"
-	consumerGroupID = "fake-consumergroup"
+	clusterID        = "fake-cluster"
+	topicID          = "fake-topic"
+	consumerGroupID  = "fake-consumergroup"
+	connectClusterID = "fake-connect-cluster"
+	connectorID      = "fake-connector"
 )
 
 // The reason why we have a fake server is because testing end-to-end will exceed the deadline of 10 minutes.
@@ -41,14 +43,20 @@ type fakeManagedKafkaServer struct {
 	managedkafkapb.UnimplementedManagedKafkaServer
 }
 
+type fakeManagedKafkaConnectServer struct {
+	managedkafkapb.UnimplementedManagedKafkaConnectServer
+}
+
 func Options(t *testing.T) []option.ClientOption {
 	server := &fakeManagedKafkaServer{}
+	connectServer := &fakeManagedKafkaConnectServer{}
 	listener, err := net.Listen("tcp", "localhost:0")
 	if err != nil {
 		t.Fatal(err)
 	}
 	gsrv := grpc.NewServer()
 	managedkafkapb.RegisterManagedKafkaServer(gsrv, server)
+	managedkafkapb.RegisterManagedKafkaConnectServer(gsrv, connectServer)
 	fakeServerAddr := listener.Addr().String()
 	go func() {
 		if err := gsrv.Serve(listener); err != nil {
@@ -165,3 +173,104 @@ func (f *fakeManagedKafkaServer) UpdateConsumerGroup(ctx context.Context, req *m
 		Name: consumerGroupID,
 	}, nil
 }
+
+// Connect server methods
+func (f *fakeManagedKafkaConnectServer) CreateConnectCluster(ctx context.Context, req *managedkafkapb.CreateConnectClusterRequest) (*longrunningpb.Operation, error) {
+	anypb := &anypb.Any{}
+	err := anypb.MarshalFrom(req.ConnectCluster)
+	if err != nil {
+		return nil, fmt.Errorf("anypb.MarshalFrom got err: %w", err)
+	}
+	return &longrunningpb.Operation{
+		Done: true,
+		Result: &longrunningpb.Operation_Response{
+			Response: anypb,
+		},
+	}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) DeleteConnectCluster(ctx context.Context, req *managedkafkapb.DeleteConnectClusterRequest) (*longrunningpb.Operation, error) {
+	return &longrunningpb.Operation{
+		Done: true,
+		Result: &longrunningpb.Operation_Response{
+			Response: &anypb.Any{},
+		},
+	}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) GetConnectCluster(ctx context.Context, req *managedkafkapb.GetConnectClusterRequest) (*managedkafkapb.ConnectCluster, error) {
+	return &managedkafkapb.ConnectCluster{
+		Name: connectClusterID,
+	}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) ListConnectClusters(ctx context.Context, req *managedkafkapb.ListConnectClustersRequest) (*managedkafkapb.ListConnectClustersResponse, error) {
+	return &managedkafkapb.ListConnectClustersResponse{
+		ConnectClusters: []*managedkafkapb.ConnectCluster{{
+			Name: connectClusterID,
+		}},
+	}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) UpdateConnectCluster(ctx context.Context, req *managedkafkapb.UpdateConnectClusterRequest) (*longrunningpb.Operation, error) {
+	anypb := &anypb.Any{}
+	err := anypb.MarshalFrom(req.ConnectCluster)
+	if err != nil {
+		return nil, fmt.Errorf("anypb.MarshalFrom got err: %w", err)
+	}
+	return &longrunningpb.Operation{
+		Done: true,
+		Result: &longrunningpb.Operation_Response{
+			Response: anypb,
+		},
+	}, nil
+}
+
+// Connector methods
+func (f *fakeManagedKafkaConnectServer) CreateConnector(ctx context.Context, req *managedkafkapb.CreateConnectorRequest) (*managedkafkapb.Connector, error) {
+	return req.Connector, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) GetConnector(ctx context.Context, req *managedkafkapb.GetConnectorRequest) (*managedkafkapb.Connector, error) {
+	return &managedkafkapb.Connector{
+		Name: connectorID,
+		Configs: map[string]string{
+			"connector.class": "test.connector",
+		},
+	}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) ListConnectors(ctx context.Context, req *managedkafkapb.ListConnectorsRequest) (*managedkafkapb.ListConnectorsResponse, error) {
+	return &managedkafkapb.ListConnectorsResponse{
+		Connectors: []*managedkafkapb.Connector{{
+			Name: connectorID,
+			Configs: map[string]string{
+				"connector.class": "test.connector",
+			},
+		}},
+	}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) UpdateConnector(ctx context.Context, req *managedkafkapb.UpdateConnectorRequest) (*managedkafkapb.Connector, error) {
+	return req.Connector, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) DeleteConnector(ctx context.Context, req *managedkafkapb.DeleteConnectorRequest) (*emptypb.Empty, error) {
+	return &emptypb.Empty{}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) PauseConnector(ctx context.Context, req *managedkafkapb.PauseConnectorRequest) (*managedkafkapb.PauseConnectorResponse, error) {
+	return &managedkafkapb.PauseConnectorResponse{}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) ResumeConnector(ctx context.Context, req *managedkafkapb.ResumeConnectorRequest) (*managedkafkapb.ResumeConnectorResponse, error) {
+	return &managedkafkapb.ResumeConnectorResponse{}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) StopConnector(ctx context.Context, req *managedkafkapb.StopConnectorRequest) (*managedkafkapb.StopConnectorResponse, error) {
+	return &managedkafkapb.StopConnectorResponse{}, nil
+}
+
+func (f *fakeManagedKafkaConnectServer) RestartConnector(ctx context.Context, req *managedkafkapb.RestartConnectorRequest) (*managedkafkapb.RestartConnectorResponse, error) {
+	return &managedkafkapb.RestartConnectorResponse{}, nil
+}

managedkafka/connect/clusters/connect_clusters_test.go

@@ -0,0 +1,100 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package clusters
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/GoogleCloudPlatform/golang-samples/internal/managedkafka/fake"
+	"github.com/GoogleCloudPlatform/golang-samples/internal/testutil"
+)
+
+const (
+	connectClusterPrefix = "connect-cluster"
+	region               = "us-central1"
+)
+
+func TestConnectClusters(t *testing.T) {
+	tc := testutil.SystemTest(t)
+	buf := new(bytes.Buffer)
+	connectClusterID := fmt.Sprintf("%s-%d", connectClusterPrefix, time.Now().UnixNano())
+	kafkaClusterID := fmt.Sprintf("kafka-cluster-%d", time.Now().UnixNano())
+	options := fake.Options(t)
+
+	// First create a Kafka cluster that the Connect cluster will reference
+	kafkaClusterPath := fmt.Sprintf("projects/%s/locations/%s/clusters/%s", tc.ProjectID, region, kafkaClusterID)
+
+	t.Run("CreateConnectCluster", func(t *testing.T) {
+		buf.Reset()
+		if err := createConnectCluster(buf, tc.ProjectID, region, connectClusterID, kafkaClusterPath, options...); err != nil {
+			t.Fatalf("failed to create a connect cluster: %v", err)
+		}
+		got := buf.String()
+		want := "Created connect cluster"
+		if !strings.Contains(got, want) {
+			t.Fatalf("createConnectCluster() mismatch got: %s\nwant: %s", got, want)
+		}
+	})
+	t.Run("GetConnectCluster", func(t *testing.T) {
+		buf.Reset()
+		if err := getConnectCluster(buf, tc.ProjectID, region, connectClusterID, options...); err != nil {
+			t.Fatalf("failed to get connect cluster: %v", err)
+		}
+		got := buf.String()
+		want := "Got connect cluster"
+		if !strings.Contains(got, want) {
+			t.Fatalf("getConnectCluster() mismatch got: %s\nwant: %s", got, want)
+		}
+	})
+	t.Run("UpdateConnectCluster", func(t *testing.T) {
+		buf.Reset()
+		memoryBytes := int64(25769803776) // 24 GiB in bytes
+		labels := map[string]string{"environment": "test"}
+		if err := updateConnectCluster(buf, tc.ProjectID, region, connectClusterID, memoryBytes, labels, options...); err != nil {
+			t.Fatalf("failed to update connect cluster: %v", err)
+		}
+		got := buf.String()
+		want := "Updated connect cluster"
+		if !strings.Contains(got, want) {
+			t.Fatalf("updateConnectCluster() mismatch got: %s\nwant: %s", got, want)
+		}
+	})
+	t.Run("ListConnectClusters", func(t *testing.T) {
+		buf.Reset()
+		if err := listConnectClusters(buf, tc.ProjectID, region, options...); err != nil {
+			t.Fatalf("failed to list connect clusters: %v", err)
+		}
+		got := buf.String()
+		want := "Got connect cluster"
+		if !strings.Contains(got, want) {
+			t.Fatalf("listConnectClusters() mismatch got: %s\nwant: %s", got, want)
+		}
+	})
+	t.Run("DeleteConnectCluster", func(t *testing.T) {
+		buf.Reset()
+		if err := deleteConnectCluster(buf, tc.ProjectID, region, connectClusterID, options...); err != nil {
+			t.Fatalf("failed to delete connect cluster: %v", err)
+		}
+		got := buf.String()
+		want := "Deleted connect cluster"
+		if !strings.Contains(got, want) {
+			t.Fatalf("deleteConnectCluster() mismatch got: %s\nwant: %s", got, want)
+		}
+	})
+}

managedkafka/connect/clusters/create_connect_cluster.go

@@ -0,0 +1,84 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package clusters
+
+// [START managedkafka_create_connect_cluster]
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"cloud.google.com/go/managedkafka/apiv1/managedkafkapb"
+	"google.golang.org/api/option"
+
+	managedkafka "cloud.google.com/go/managedkafka/apiv1"
+)
+
+func createConnectCluster(w io.Writer, projectID, region, clusterID, kafkaCluster string, opts ...option.ClientOption) error {
+	// projectID := "my-project-id"
+	// region := "us-central1"
+	// clusterID := "my-connect-cluster"
+	// kafkaCluster := "projects/my-project-id/locations/us-central1/clusters/my-kafka-cluster"
+	ctx := context.Background()
+	client, err := managedkafka.NewManagedKafkaConnectClient(ctx, opts...)
+	if err != nil {
+		return fmt.Errorf("managedkafka.NewManagedKafkaConnectClient got err: %w", err)
+	}
+	defer client.Close()
+
+	locationPath := fmt.Sprintf("projects/%s/locations/%s", projectID, region)
+	clusterPath := fmt.Sprintf("%s/connectClusters/%s", locationPath, clusterID)
+
+	// Capacity configuration with 12 vCPU and 12 GiB RAM
+	capacityConfig := &managedkafkapb.CapacityConfig{
+		VcpuCount:   12,
+		MemoryBytes: 12884901888, // 12 GiB in bytes
+	}
+
+	// Optionally, you can also specify accessible subnets and resolvable DNS
+	// domains as part of your network configuration. For example:
+	// networkConfigs := []*managedkafkapb.ConnectNetworkConfig{
+	// 	{
+	// 		PrimarySubnet:      primarySubnet,
+	// 		AdditionalSubnets:  []string{"subnet-1", "subnet-2"},
+	// 		DnsDomainNames:     []string{"domain-1", "domain-2"},
+	// 	},
+	// }
+
+	connectCluster := &managedkafkapb.ConnectCluster{
+		Name:           clusterPath,
+		KafkaCluster:   kafkaCluster,
+		CapacityConfig: capacityConfig,
+	}
+
+	req := &managedkafkapb.CreateConnectClusterRequest{
+		Parent:           locationPath,
+		ConnectClusterId: clusterID,
+		ConnectCluster:   connectCluster,
+	}
+	op, err := client.CreateConnectCluster(ctx, req)
+	if err != nil {
+		return fmt.Errorf("client.CreateConnectCluster got err: %w", err)
+	}
+	// The duration of this operation can vary considerably, typically taking 5-15 minutes.
+	resp, err := op.Wait(ctx)
+	if err != nil {
+		return fmt.Errorf("op.Wait got err: %w", err)
+	}
+	fmt.Fprintf(w, "Created connect cluster: %s\n", resp.Name)
+	return nil
+}
+
+// [END managedkafka_create_connect_cluster]

managedkafka/connect/clusters/delete_connect_cluster.go

@@ -0,0 +1,56 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package clusters
+
+// [START managedkafka_delete_connect_cluster]
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"cloud.google.com/go/managedkafka/apiv1/managedkafkapb"
+	"google.golang.org/api/option"
+
+	managedkafka "cloud.google.com/go/managedkafka/apiv1"
+)
+
+func deleteConnectCluster(w io.Writer, projectID, region, clusterID string, opts ...option.ClientOption) error {
+	// projectID := "my-project-id"
+	// region := "us-central1"
+	// clusterID := "my-connect-cluster"
+	ctx := context.Background()
+	client, err := managedkafka.NewManagedKafkaConnectClient(ctx, opts...)
+	if err != nil {
+		return fmt.Errorf("managedkafka.NewManagedKafkaConnectClient got err: %w", err)
+	}
+	defer client.Close()
+
+	clusterPath := fmt.Sprintf("projects/%s/locations/%s/connectClusters/%s", projectID, region, clusterID)
+	req := &managedkafkapb.DeleteConnectClusterRequest{
+		Name: clusterPath,
+	}
+	op, err := client.DeleteConnectCluster(ctx, req)
+	if err != nil {
+		return fmt.Errorf("client.DeleteConnectCluster got err: %w", err)
+	}
+	err = op.Wait(ctx)
+	if err != nil {
+		return fmt.Errorf("op.Wait got err: %w", err)
+	}
+	fmt.Fprint(w, "Deleted connect cluster\n")
+	return nil
+}
+
+// [END managedkafka_delete_connect_cluster]