✨ add grpc option for cloudevents client.

cloudevents/generic/options/grpc/agentoptions.go

@@ -0,0 +1,76 @@
+package grpc
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	cloudevents "github.com/cloudevents/sdk-go/v2"
+	cecontext "github.com/cloudevents/sdk-go/v2/context"
+
+	"open-cluster-management.io/api/cloudevents/generic/options"
+	"open-cluster-management.io/api/cloudevents/generic/options/grpc/protocol"
+	"open-cluster-management.io/api/cloudevents/generic/types"
+)
+
+type grpcAgentOptions struct {
+	GRPCOptions
+	errorChan   chan error // grpc client connection doesn't have error channel, it will handle reconnecting automatically
+	clusterName string
+}
+
+func NewAgentOptions(grpcOptions *GRPCOptions, clusterName, agentID string) *options.CloudEventsAgentOptions {
+	return &options.CloudEventsAgentOptions{
+		CloudEventsOptions: &grpcAgentOptions{
+			GRPCOptions: *grpcOptions,
+			errorChan:   make(chan error),
+			clusterName: clusterName,
+		},
+		AgentID:     agentID,
+		ClusterName: clusterName,
+	}
+}
+
+func (o *grpcAgentOptions) WithContext(ctx context.Context, evtCtx cloudevents.EventContext) (context.Context, error) {
+	eventType, err := types.ParseCloudEventsType(evtCtx.GetType())
+	if err != nil {
+		return nil, fmt.Errorf("unsupported event type %s, %v", eventType, err)
+	}
+
+	if eventType.Action == types.ResyncRequestAction {
+		// agent publishes event to spec resync topic to request to get resources spec from all sources
+		topic := strings.Replace(SpecResyncTopic, "+", o.clusterName, -1)
+		return cecontext.WithTopic(ctx, topic), nil
+	}
+
+	// agent publishes event to status topic to send the resource status from a specified cluster
+	originalSource, err := evtCtx.GetExtension(types.ExtensionOriginalSource)
+	if err != nil {
+		return nil, err
+	}
+
+	statusTopic := strings.Replace(StatusTopic, "+", fmt.Sprintf("%s", originalSource), 1)
+	statusTopic = strings.Replace(statusTopic, "+", o.clusterName, -1)
+	return cecontext.WithTopic(ctx, statusTopic), nil
+}
+
+func (o *grpcAgentOptions) Client(ctx context.Context) (cloudevents.Client, error) {
+	receiver, err := o.GetCloudEventsClient(
+		ctx,
+		protocol.WithPublishOption(&protocol.PublishOption{}),
+		protocol.WithSubscribeOption(&protocol.SubscribeOption{
+			Topics: []string{
+				replaceNth(SpecTopic, "+", o.clusterName, 2), // receiving the resources spec from sources with spec topic
+				StatusResyncTopic, // receiving the resources status resync request from sources with status resync topic
+			},
+		}),
+	)
+	if err != nil {
+		return nil, err
+	}
+	return receiver, nil
+}
+
+func (o *grpcAgentOptions) ErrorChan() <-chan error {
+	return o.errorChan
+}

cloudevents/generic/options/grpc/agentoptions_test.go

@@ -0,0 +1,123 @@
+package grpc
+
+import (
+	"context"
+	"testing"
+
+	cloudevents "github.com/cloudevents/sdk-go/v2"
+	cloudeventscontext "github.com/cloudevents/sdk-go/v2/context"
+
+	"open-cluster-management.io/api/cloudevents/generic/types"
+)
+
+var mockEventDataType = types.CloudEventsDataType{
+	Group:    "resources.test",
+	Version:  "v1",
+	Resource: "mockresources",
+}
+
+func TestAgentContext(t *testing.T) {
+	cases := []struct {
+		name          string
+		event         cloudevents.Event
+		expectedTopic string
+		assertError   func(error)
+	}{
+		{
+			name: "unsupported event",
+			event: func() cloudevents.Event {
+				evt := cloudevents.NewEvent()
+				evt.SetType("unsupported")
+				return evt
+			}(),
+			assertError: func(err error) {
+				if err == nil {
+					t.Errorf("expected error, but failed")
+				}
+			},
+		},
+		{
+			name: "resync specs",
+			event: func() cloudevents.Event {
+				eventType := types.CloudEventsType{
+					CloudEventsDataType: mockEventDataType,
+					SubResource:         types.SubResourceSpec,
+					Action:              types.ResyncRequestAction,
+				}
+
+				evt := cloudevents.NewEvent()
+				evt.SetType(eventType.String())
+				evt.SetExtension("clustername", "cluster1")
+				return evt
+			}(),
+			expectedTopic: "sources/clusters/cluster1/specresync",
+			assertError: func(err error) {
+				if err != nil {
+					t.Errorf("unexpected error %v", err)
+				}
+			},
+		},
+		{
+			name: "send status no original source",
+			event: func() cloudevents.Event {
+				eventType := types.CloudEventsType{
+					CloudEventsDataType: mockEventDataType,
+					SubResource:         types.SubResourceStatus,
+					Action:              "test",
+				}
+
+				evt := cloudevents.NewEvent()
+				evt.SetSource("hub1")
+				evt.SetType(eventType.String())
+				return evt
+			}(),
+			assertError: func(err error) {
+				if err == nil {
+					t.Errorf("expected error, but failed")
+				}
+			},
+		},
+		{
+			name: "send status",
+			event: func() cloudevents.Event {
+				eventType := types.CloudEventsType{
+					CloudEventsDataType: mockEventDataType,
+					SubResource:         types.SubResourceStatus,
+					Action:              "test",
+				}
+
+				evt := cloudevents.NewEvent()
+				evt.SetSource("agent")
+				evt.SetType(eventType.String())
+				evt.SetExtension("originalsource", "hub1")
+				return evt
+			}(),
+			expectedTopic: "sources/hub1/clusters/cluster1/status",
+			assertError: func(err error) {
+				if err != nil {
+					t.Errorf("unexpected error %v", err)
+				}
+			},
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			agentOptions := &grpcAgentOptions{clusterName: "cluster1"}
+			ctx, err := agentOptions.WithContext(context.TODO(), c.event.Context)
+			c.assertError(err)
+
+			topic := func(ctx context.Context) string {
+				if ctx == nil {
+					return ""
+				}
+
+				return cloudeventscontext.TopicFrom(ctx)
+			}(ctx)
+
+			if topic != c.expectedTopic {
+				t.Errorf("expected %s, but got %s", c.expectedTopic, topic)
+			}
+		})
+	}
+}

cloudevents/generic/options/grpc/options.go

@@ -0,0 +1,166 @@
+package grpc
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"os"
+	"strings"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/credentials/insecure"
+	"gopkg.in/yaml.v2"
+
+	cloudevents "github.com/cloudevents/sdk-go/v2"
+
+	"open-cluster-management.io/api/cloudevents/generic/options/grpc/protocol"
+)
+
+const (
+	// SpecTopic is a pubsub topic for resource spec.
+	SpecTopic = "sources/+/clusters/+/spec"
+
+	// StatusTopic is a pubsub topic for resource status.
+	StatusTopic = "sources/+/clusters/+/status"
+
+	// SpecResyncTopic is a pubsub topic for resource spec resync.
+	SpecResyncTopic = "sources/clusters/+/specresync"
+
+	// StatusResyncTopic is a pubsub topic for resource status resync.
+	StatusResyncTopic = "sources/+/clusters/statusresync"
+)
+
+// GRPCOptions holds the options that are used to build gRPC client.
+type GRPCOptions struct {
+	URL            string
+	CAFile         string
+	ClientCertFile string
+	ClientKeyFile  string
+}
+
+// GRPCConfig holds the information needed to build connect to gRPC server as a given user.
+type GRPCConfig struct {
+	// URL is the address of the gRPC server (host:port).
+	URL string `json:"url" yaml:"url"`
+	// CAFile is the file path to a cert file for the gRPC server certificate authority.
+	CAFile string `json:"caFile,omitempty" yaml:"caFile,omitempty"`
+	// ClientCertFile is the file path to a client cert file for TLS.
+	ClientCertFile string `json:"clientCertFile,omitempty" yaml:"clientCertFile,omitempty"`
+	// ClientKeyFile is the file path to a client key file for TLS.
+	ClientKeyFile string `json:"clientKeyFile,omitempty" yaml:"clientKeyFile,omitempty"`
+}
+
+// BuildGRPCOptionsFromFlags builds configs from a config filepath.
+func BuildGRPCOptionsFromFlags(configPath string) (*GRPCOptions, error) {
+	configData, err := os.ReadFile(configPath)
+	if err != nil {
+		return nil, err
+	}
+
+	config := &GRPCConfig{}
+	if err := yaml.Unmarshal(configData, config); err != nil {
+		return nil, err
+	}
+
+	if config.URL == "" {
+		return nil, fmt.Errorf("url is required")
+	}
+
+	if (config.ClientCertFile == "" && config.ClientKeyFile != "") ||
+		(config.ClientCertFile != "" && config.ClientKeyFile == "") {
+		return nil, fmt.Errorf("either both or none of clientCertFile and clientKeyFile must be set")
+	}
+	if config.ClientCertFile != "" && config.ClientKeyFile != "" && config.CAFile == "" {
+		return nil, fmt.Errorf("setting clientCertFile and clientKeyFile requires caFile")
+	}
+
+	return &GRPCOptions{
+		URL:            config.URL,
+		CAFile:         config.CAFile,
+		ClientCertFile: config.ClientCertFile,
+		ClientKeyFile:  config.ClientKeyFile,
+	}, nil
+}
+
+func NewGRPCOptions() *GRPCOptions {
+	return &GRPCOptions{}
+}
+
+func (o *GRPCOptions) GetGRPCClientConn() (*grpc.ClientConn, error) {
+	if len(o.CAFile) != 0 {
+		certPool, err := x509.SystemCertPool()
+		if err != nil {
+			return nil, err
+		}
+
+		caPEM, err := os.ReadFile(o.CAFile)
+		if err != nil {
+			return nil, err
+		}
+
+		if ok := certPool.AppendCertsFromPEM(caPEM); !ok {
+			return nil, fmt.Errorf("invalid CA %s", o.CAFile)
+		}
+
+		clientCerts, err := tls.LoadX509KeyPair(o.ClientCertFile, o.ClientKeyFile)
+		if err != nil {
+			return nil, err
+		}
+
+		tlsConfig := &tls.Config{
+			Certificates: []tls.Certificate{clientCerts},
+			RootCAs:      certPool,
+			MinVersion:   tls.VersionTLS13,
+			MaxVersion:   tls.VersionTLS13,
+		}
+
+		conn, err := grpc.Dial(o.URL, grpc.WithTransportCredentials(credentials.NewTLS(tlsConfig)))
+		if err != nil {
+			return nil, fmt.Errorf("failed to connect to grpc server %s, %v", o.URL, err)
+		}
+
+		return conn, nil
+	}
+
+	conn, err := grpc.Dial(o.URL, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to grpc server %s, %v", o.URL, err)
+	}
+
+	return conn, nil
+}
+
+func (o *GRPCOptions) GetCloudEventsClient(ctx context.Context, clientOpts ...protocol.Option) (cloudevents.Client, error) {
+	conn, err := o.GetGRPCClientConn()
+	if err != nil {
+		return nil, err
+	}
+
+	opts := []protocol.Option{}
+	opts = append(opts, clientOpts...)
+	p, err := protocol.NewProtocol(conn, opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return cloudevents.NewClient(p)
+}
+
+// Replace the nth occurrence of old in str by new.
+func replaceNth(str, old, new string, n int) string {
+	i := 0
+	for m := 1; m <= n; m++ {
+		x := strings.Index(str[i:], old)
+		if x < 0 {
+			break
+		}
+		i += x
+		if m == n {
+			return str[:i] + new + str[i+len(old):]
+		}
+		i += len(old)
+	}
+	return str
+}