contrib/recipes: use clientv3 lease API

contrib/recipes/lease.go

@@ -15,11 +15,9 @@ package recipe
 
 import (
 	"sync"
-	"time"
 
 	"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
 	"github.com/coreos/etcd/clientv3"
-	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
 	"github.com/coreos/etcd/lease"
 )
 
@@ -32,8 +30,9 @@ type clientLeaseMgr struct {
 }
 
 type leaseKeepAlive struct {
-	id    lease.LeaseID
-	donec chan struct{}
+	id     lease.LeaseID
+	cancel context.CancelFunc
+	donec  <-chan struct{}
 }
 
 func SessionLease(client *clientv3.Client) (lease.LeaseID, error) {
@@ -49,13 +48,10 @@ func SessionLeaseTTL(client *clientv3.Client, ttl int64) (lease.LeaseID, error)
 // would fail) or if transferring lease ownership.
 func StopSessionLease(client *clientv3.Client) {
 	clientLeases.mu.Lock()
-	lka, ok := clientLeases.leases[client]
-	if ok {
-		delete(clientLeases.leases, client)
-	}
+	lka := clientLeases.leases[client]
 	clientLeases.mu.Unlock()
 	if lka != nil {
-		lka.donec <- struct{}{}
+		lka.cancel()
 		<-lka.donec
 	}
 }
@@ -67,8 +63,7 @@ func RevokeSessionLease(client *clientv3.Client) (err error) {
 	clientLeases.mu.Unlock()
 	StopSessionLease(client)
 	if lka != nil {
-		req := &pb.LeaseRevokeRequest{ID: int64(lka.id)}
-		_, err = client.Lease.LeaseRevoke(context.TODO(), req)
+		_, err = clientv3.NewLease(client).Revoke(context.TODO(), lka.id)
 	}
 	return err
 }
@@ -80,48 +75,37 @@ func (clm *clientLeaseMgr) sessionLease(client *clientv3.Client, ttl int64) (lea
 		return lka.id, nil
 	}
 
-	resp, err := client.Lease.LeaseCreate(context.TODO(), &pb.LeaseCreateRequest{TTL: ttl})
+	lc := clientv3.NewLease(client)
+	resp, err := lc.Create(context.TODO(), ttl)
 	if err != nil {
 		return lease.NoLease, err
 	}
 	id := lease.LeaseID(resp.ID)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	keepAlive, err := client.Lease.LeaseKeepAlive(ctx)
+	keepAlive, err := lc.KeepAlive(ctx, id)
 	if err != nil || keepAlive == nil {
 		return lease.NoLease, err
 	}
 
-	lka := &leaseKeepAlive{id: id, donec: make(chan struct{})}
+	donec := make(chan struct{})
+	lka := &leaseKeepAlive{
+		id:     id,
+		cancel: cancel,
+		donec:  donec}
 	clm.leases[client] = lka
 
-	// keep the lease alive until client error
+	// keep the lease alive until client error or cancelled context
 	go func() {
 		defer func() {
-			keepAlive.CloseSend()
 			clm.mu.Lock()
 			delete(clm.leases, client)
 			clm.mu.Unlock()
-			cancel()
-			close(lka.donec)
+			lc.Close()
+			close(donec)
 		}()
-
-		ttl := resp.TTL
-		for {
-			lreq := &pb.LeaseKeepAliveRequest{ID: int64(id)}
-			select {
-			case <-lka.donec:
-				return
-			case <-time.After(time.Duration(ttl/2) * time.Second):
-			}
-			if err := keepAlive.Send(lreq); err != nil {
-				break
-			}
-			resp, err := keepAlive.Recv()
-			if err != nil {
-				break
-			}
-			ttl = resp.TTL
+		for range keepAlive {
+			// eat messages until keep alive channel closes
 		}
 	}()