server: Move server files to 'server' directory.

26  git mv mvcc wal auth etcdserver etcdmain proxy embed/ lease/ server
   36  git mv go.mod go.sum server

server/proxy/grpcproxy/cluster.go

@@ -0,0 +1,205 @@
+// Copyright 2016 The etcd 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 grpcproxy
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"sync"
+
+	pb "go.etcd.io/etcd/api/v3/etcdserverpb"
+	"go.etcd.io/etcd/api/v3/v3rpc/rpctypes"
+	"go.etcd.io/etcd/client/v3"
+	"go.etcd.io/etcd/client/v3/naming"
+
+	"go.uber.org/zap"
+	"golang.org/x/time/rate"
+	gnaming "google.golang.org/grpc/naming"
+)
+
+// allow maximum 1 retry per second
+const resolveRetryRate = 1
+
+type clusterProxy struct {
+	lg   *zap.Logger
+	clus clientv3.Cluster
+	ctx  context.Context
+	gr   *naming.GRPCResolver
+
+	// advertise client URL
+	advaddr string
+	prefix  string
+
+	umu  sync.RWMutex
+	umap map[string]gnaming.Update
+}
+
+// NewClusterProxy takes optional prefix to fetch grpc-proxy member endpoints.
+// The returned channel is closed when there is grpc-proxy endpoint registered
+// and the client's context is canceled so the 'register' loop returns.
+func NewClusterProxy(lg *zap.Logger, c *clientv3.Client, advaddr string, prefix string) (pb.ClusterServer, <-chan struct{}) {
+	if lg == nil {
+		lg = zap.NewNop()
+	}
+	cp := &clusterProxy{
+		lg:   lg,
+		clus: c.Cluster,
+		ctx:  c.Ctx(),
+		gr:   &naming.GRPCResolver{Client: c},
+
+		advaddr: advaddr,
+		prefix:  prefix,
+		umap:    make(map[string]gnaming.Update),
+	}
+
+	donec := make(chan struct{})
+	if advaddr != "" && prefix != "" {
+		go func() {
+			defer close(donec)
+			cp.resolve(prefix)
+		}()
+		return cp, donec
+	}
+
+	close(donec)
+	return cp, donec
+}
+
+func (cp *clusterProxy) resolve(prefix string) {
+	rm := rate.NewLimiter(rate.Limit(resolveRetryRate), resolveRetryRate)
+	for rm.Wait(cp.ctx) == nil {
+		wa, err := cp.gr.Resolve(prefix)
+		if err != nil {
+			cp.lg.Warn("failed to resolve prefix", zap.String("prefix", prefix), zap.Error(err))
+			continue
+		}
+		cp.monitor(wa)
+	}
+}
+
+func (cp *clusterProxy) monitor(wa gnaming.Watcher) {
+	for cp.ctx.Err() == nil {
+		ups, err := wa.Next()
+		if err != nil {
+			cp.lg.Warn("clusterProxy watcher error", zap.Error(err))
+			if rpctypes.ErrorDesc(err) == naming.ErrWatcherClosed.Error() {
+				return
+			}
+		}
+
+		cp.umu.Lock()
+		for i := range ups {
+			switch ups[i].Op {
+			case gnaming.Add:
+				cp.umap[ups[i].Addr] = *ups[i]
+			case gnaming.Delete:
+				delete(cp.umap, ups[i].Addr)
+			}
+		}
+		cp.umu.Unlock()
+	}
+}
+
+func (cp *clusterProxy) MemberAdd(ctx context.Context, r *pb.MemberAddRequest) (*pb.MemberAddResponse, error) {
+	if r.IsLearner {
+		return cp.memberAddAsLearner(ctx, r.PeerURLs)
+	}
+	return cp.memberAdd(ctx, r.PeerURLs)
+}
+
+func (cp *clusterProxy) memberAdd(ctx context.Context, peerURLs []string) (*pb.MemberAddResponse, error) {
+	mresp, err := cp.clus.MemberAdd(ctx, peerURLs)
+	if err != nil {
+		return nil, err
+	}
+	resp := (pb.MemberAddResponse)(*mresp)
+	return &resp, err
+}
+
+func (cp *clusterProxy) memberAddAsLearner(ctx context.Context, peerURLs []string) (*pb.MemberAddResponse, error) {
+	mresp, err := cp.clus.MemberAddAsLearner(ctx, peerURLs)
+	if err != nil {
+		return nil, err
+	}
+	resp := (pb.MemberAddResponse)(*mresp)
+	return &resp, err
+}
+
+func (cp *clusterProxy) MemberRemove(ctx context.Context, r *pb.MemberRemoveRequest) (*pb.MemberRemoveResponse, error) {
+	mresp, err := cp.clus.MemberRemove(ctx, r.ID)
+	if err != nil {
+		return nil, err
+	}
+	resp := (pb.MemberRemoveResponse)(*mresp)
+	return &resp, err
+}
+
+func (cp *clusterProxy) MemberUpdate(ctx context.Context, r *pb.MemberUpdateRequest) (*pb.MemberUpdateResponse, error) {
+	mresp, err := cp.clus.MemberUpdate(ctx, r.ID, r.PeerURLs)
+	if err != nil {
+		return nil, err
+	}
+	resp := (pb.MemberUpdateResponse)(*mresp)
+	return &resp, err
+}
+
+func (cp *clusterProxy) membersFromUpdates() ([]*pb.Member, error) {
+	cp.umu.RLock()
+	defer cp.umu.RUnlock()
+	mbs := make([]*pb.Member, 0, len(cp.umap))
+	for addr, upt := range cp.umap {
+		m, err := decodeMeta(fmt.Sprint(upt.Metadata))
+		if err != nil {
+			return nil, err
+		}
+		mbs = append(mbs, &pb.Member{Name: m.Name, ClientURLs: []string{addr}})
+	}
+	return mbs, nil
+}
+
+// MemberList wraps member list API with following rules:
+// - If 'advaddr' is not empty and 'prefix' is not empty, return registered member lists via resolver
+// - If 'advaddr' is not empty and 'prefix' is not empty and registered grpc-proxy members haven't been fetched, return the 'advaddr'
+// - If 'advaddr' is not empty and 'prefix' is empty, return 'advaddr' without forcing it to 'register'
+// - If 'advaddr' is empty, forward to member list API
+func (cp *clusterProxy) MemberList(ctx context.Context, r *pb.MemberListRequest) (*pb.MemberListResponse, error) {
+	if cp.advaddr != "" {
+		if cp.prefix != "" {
+			mbs, err := cp.membersFromUpdates()
+			if err != nil {
+				return nil, err
+			}
+			if len(mbs) > 0 {
+				return &pb.MemberListResponse{Members: mbs}, nil
+			}
+		}
+		// prefix is empty or no grpc-proxy members haven't been registered
+		hostname, _ := os.Hostname()
+		return &pb.MemberListResponse{Members: []*pb.Member{{Name: hostname, ClientURLs: []string{cp.advaddr}}}}, nil
+	}
+	mresp, err := cp.clus.MemberList(ctx)
+	if err != nil {
+		return nil, err
+	}
+	resp := (pb.MemberListResponse)(*mresp)
+	return &resp, err
+}
+
+func (cp *clusterProxy) MemberPromote(ctx context.Context, r *pb.MemberPromoteRequest) (*pb.MemberPromoteResponse, error) {
+	// TODO: implement
+	return nil, errors.New("not implemented")
+}