admin: implement admin services (#4274)

admin/admin.go

@@ -0,0 +1,57 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * 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
+ *
+ *     http://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 admin provides a convenient method for registering a collection of
+// administration services to a gRPC server. The services registered are:
+//
+// - Channelz: https://github.com/grpc/proposal/blob/master/A14-channelz.md
+// - CSDS: https://github.com/grpc/proposal/blob/master/A40-csds-support.md
+//
+// Experimental
+//
+// Notice: All APIs in this package are experimental and may be removed in a
+// later release.
+package admin
+
+import (
+	"google.golang.org/grpc"
+	channelzservice "google.golang.org/grpc/channelz/service"
+	internaladmin "google.golang.org/grpc/internal/admin"
+)
+
+func init() {
+	// Add a list of default services to admin here. Optional services, like
+	// CSDS, will be added by other packages.
+	internaladmin.AddService(func(registrar grpc.ServiceRegistrar) (func(), error) {
+		channelzservice.RegisterChannelzServiceToServer(registrar)
+		return nil, nil
+	})
+}
+
+// Register registers the set of admin services to the given server.
+//
+// The returned cleanup function should be called to clean up the resources
+// allocated for the service handlers after the server is stopped.
+//
+// Note that if `s` is not a *grpc.Server or a *xds.GRPCServer, CSDS will not be
+// registered because CSDS generated code is old and doesn't support interface
+// `grpc.ServiceRegistrar`.
+// https://github.com/envoyproxy/go-control-plane/issues/403
+func Register(s grpc.ServiceRegistrar) (cleanup func(), _ error) {
+	return internaladmin.Register(s)
+}

admin/admin_test.go

@@ -0,0 +1,34 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * 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
+ *
+ *     http://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 admin_test
+
+import (
+	"testing"
+
+	"google.golang.org/grpc/admin/test"
+	"google.golang.org/grpc/codes"
+)
+
+func TestRegisterNoCSDS(t *testing.T) {
+	test.RunRegisterTests(t, test.ExpectedStatusCodes{
+		ChannelzCode: codes.OK,
+		// CSDS is not registered because xDS isn't imported.
+		CSDSCode: codes.Unimplemented,
+	})
+}

admin/test/admin_test.go

@@ -0,0 +1,38 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * 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
+ *
+ *     http://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.
+ *
+ */
+
+// This file has the same content as admin_test.go, difference is that this is
+// in another package, and it imports "xds", so we can test that csds is
+// registered when xds is imported.
+
+package test_test
+
+import (
+	"testing"
+
+	"google.golang.org/grpc/admin/test"
+	"google.golang.org/grpc/codes"
+	_ "google.golang.org/grpc/xds"
+)
+
+func TestRegisterWithCSDS(t *testing.T) {
+	test.RunRegisterTests(t, test.ExpectedStatusCodes{
+		ChannelzCode: codes.OK,
+		CSDSCode:     codes.OK,
+	})
+}

admin/test/utils.go

@@ -0,0 +1,113 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * 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
+ *
+ *     http://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 test contains test only functions for package admin. It's used by
+// admin/admin_test.go and admin/test/admin_test.go.
+package test
+
+import (
+	"context"
+	"net"
+	"testing"
+	"time"
+
+	v3statuspb "github.com/envoyproxy/go-control-plane/envoy/service/status/v3"
+	"github.com/google/uuid"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/admin"
+	channelzpb "google.golang.org/grpc/channelz/grpc_channelz_v1"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/internal/xds"
+	"google.golang.org/grpc/status"
+)
+
+const (
+	defaultTestTimeout = 10 * time.Second
+)
+
+// ExpectedStatusCodes contains the expected status code for each RPC (can be
+// OK).
+type ExpectedStatusCodes struct {
+	ChannelzCode codes.Code
+	CSDSCode     codes.Code
+}
+
+// RunRegisterTests makes a client, runs the RPCs, and compares the status
+// codes.
+func RunRegisterTests(t *testing.T, ec ExpectedStatusCodes) {
+	nodeID := uuid.New().String()
+	bootstrapCleanup, err := xds.SetupBootstrapFile(xds.BootstrapOptions{
+		Version:   xds.TransportV3,
+		NodeID:    nodeID,
+		ServerURI: "no.need.for.a.server",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer bootstrapCleanup()
+
+	lis, err := net.Listen("tcp", "localhost:0")
+	if err != nil {
+		t.Fatalf("cannot create listener: %v", err)
+	}
+
+	server := grpc.NewServer()
+	defer server.Stop()
+	cleanup, err := admin.Register(server)
+	if err != nil {
+		t.Fatalf("failed to register admin: %v", err)
+	}
+	defer cleanup()
+	go func() {
+		server.Serve(lis)
+	}()
+
+	conn, err := grpc.Dial(lis.Addr().String(), grpc.WithInsecure())
+	if err != nil {
+		t.Fatalf("cannot connect to server: %v", err)
+	}
+
+	t.Run("channelz", func(t *testing.T) {
+		if err := RunChannelz(conn); status.Code(err) != ec.ChannelzCode {
+			t.Fatalf("%s RPC failed with error %v, want code %v", "channelz", err, ec.ChannelzCode)
+		}
+	})
+	t.Run("csds", func(t *testing.T) {
+		if err := RunCSDS(conn); status.Code(err) != ec.CSDSCode {
+			t.Fatalf("%s RPC failed with error %v, want code %v", "CSDS", err, ec.CSDSCode)
+		}
+	})
+}
+
+// RunChannelz makes a channelz RPC.
+func RunChannelz(conn *grpc.ClientConn) error {
+	c := channelzpb.NewChannelzClient(conn)
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	_, err := c.GetTopChannels(ctx, &channelzpb.GetTopChannelsRequest{}, grpc.WaitForReady(true))
+	return err
+}
+
+// RunCSDS makes a CSDS RPC.
+func RunCSDS(conn *grpc.ClientConn) error {
+	c := v3statuspb.NewClientStatusDiscoveryServiceClient(conn)
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	_, err := c.FetchClientStatus(ctx, &v3statuspb.ClientStatusRequest{}, grpc.WaitForReady(true))
+	return err
+}

channelz/service/service.go

@@ -43,7 +43,7 @@ func init() {
 var logger = grpclog.Component("channelz")
 
 // RegisterChannelzServiceToServer registers the channelz service to the given server.
-func RegisterChannelzServiceToServer(s *grpc.Server) {
+func RegisterChannelzServiceToServer(s grpc.ServiceRegistrar) {
 	channelzgrpc.RegisterChannelzServer(s, newCZServer())
 }
 

internal/admin/admin.go

@@ -0,0 +1,60 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * 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
+ *
+ *     http://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 admin contains internal implementation for admin service.
+package admin
+
+import "google.golang.org/grpc"
+
+// services is a map from name to service register functions.
+var services []func(grpc.ServiceRegistrar) (func(), error)
+
+// AddService adds a service to the list of admin services.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe.
+//
+// If multiple services with the same service name are added (e.g. two services
+// for `grpc.channelz.v1.Channelz`), the server will panic on `Register()`.
+func AddService(f func(grpc.ServiceRegistrar) (func(), error)) {
+	services = append(services, f)
+}
+
+// Register registers the set of admin services to the given server.
+func Register(s grpc.ServiceRegistrar) (cleanup func(), _ error) {
+	var cleanups []func()
+	for _, f := range services {
+		cleanup, err := f(s)
+		if err != nil {
+			callFuncs(cleanups)
+			return nil, err
+		}
+		if cleanup != nil {
+			cleanups = append(cleanups, cleanup)
+		}
+	}
+	return func() {
+		callFuncs(cleanups)
+	}, nil
+}
+
+func callFuncs(fs []func()) {
+	for _, f := range fs {
+		f()
+	}
+}