Dependencies for the affinity router and the
affinity routing daemon.
Change-Id: Icda72c3594ef7f8f0bc0c33dc03087a4c25529ca
diff --git a/vendor/github.com/coreos/etcd/proxy/grpcproxy/register.go b/vendor/github.com/coreos/etcd/proxy/grpcproxy/register.go
new file mode 100644
index 0000000..598c71f
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/proxy/grpcproxy/register.go
@@ -0,0 +1,94 @@
+// Copyright 2017 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 (
+ "encoding/json"
+ "os"
+
+ "github.com/coreos/etcd/clientv3"
+ "github.com/coreos/etcd/clientv3/concurrency"
+ "github.com/coreos/etcd/clientv3/naming"
+
+ "golang.org/x/time/rate"
+ gnaming "google.golang.org/grpc/naming"
+)
+
+// allow maximum 1 retry per second
+const registerRetryRate = 1
+
+// Register registers itself as a grpc-proxy server by writing prefixed-key
+// with session of specified TTL (in seconds). The returned channel is closed
+// when the client's context is canceled.
+func Register(c *clientv3.Client, prefix string, addr string, ttl int) <-chan struct{} {
+ rm := rate.NewLimiter(rate.Limit(registerRetryRate), registerRetryRate)
+
+ donec := make(chan struct{})
+ go func() {
+ defer close(donec)
+
+ for rm.Wait(c.Ctx()) == nil {
+ ss, err := registerSession(c, prefix, addr, ttl)
+ if err != nil {
+ plog.Warningf("failed to create a session %v", err)
+ continue
+ }
+ select {
+ case <-c.Ctx().Done():
+ ss.Close()
+ return
+
+ case <-ss.Done():
+ plog.Warning("session expired; possible network partition or server restart")
+ plog.Warning("creating a new session to rejoin")
+ continue
+ }
+ }
+ }()
+
+ return donec
+}
+
+func registerSession(c *clientv3.Client, prefix string, addr string, ttl int) (*concurrency.Session, error) {
+ ss, err := concurrency.NewSession(c, concurrency.WithTTL(ttl))
+ if err != nil {
+ return nil, err
+ }
+
+ gr := &naming.GRPCResolver{Client: c}
+ if err = gr.Update(c.Ctx(), prefix, gnaming.Update{Op: gnaming.Add, Addr: addr, Metadata: getMeta()}, clientv3.WithLease(ss.Lease())); err != nil {
+ return nil, err
+ }
+
+ plog.Infof("registered %q with %d-second lease", addr, ttl)
+ return ss, nil
+}
+
+// meta represents metadata of proxy register.
+type meta struct {
+ Name string `json:"name"`
+}
+
+func getMeta() string {
+ hostname, _ := os.Hostname()
+ bts, _ := json.Marshal(meta{Name: hostname})
+ return string(bts)
+}
+
+func decodeMeta(s string) (meta, error) {
+ m := meta{}
+ err := json.Unmarshal([]byte(s), &m)
+ return m, err
+}