Log: debug user cancellation and log warning for rest

The context errors with Canceled or DeadlineExceeded code are typically for user
cancellation which should be at debug level. For other error codes we should
display a warning.

Fixes etcd-io#9085

etcdserver/api/v3rpc/lease.go

@@ -22,6 +22,9 @@ import (
 	"github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes"
 	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
 	"github.com/coreos/etcd/lease"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 type LeaseServer struct {
@@ -107,7 +110,13 @@ func (ls *LeaseServer) leaseKeepAlive(stream pb.Lease_LeaseKeepAliveServer) erro
 			return nil
 		}
 		if err != nil {
-			plog.Debugf("failed to receive lease keepalive request from gRPC stream (%q)", err.Error())
+			ev, _ := status.FromError(err)
+			code := ev.Code()
+			if code == codes.Canceled || code == codes.DeadlineExceeded {
+				plog.Debugf("failed to receive lease 123 keepalive request from gRPC stream (%q)", err.Error())
+			} else {
+				plog.Warningf("failed to receive lease keepalive request from gRPC stream (%q)", err.Error())
+			}
 			return err
 		}
 

etcdserver/api/v3rpc/watch.go

@@ -26,6 +26,9 @@ import (
 	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
 	"github.com/coreos/etcd/mvcc"
 	"github.com/coreos/etcd/mvcc/mvccpb"
+
+    "google.golang.org/grpc/codes"
+    "google.golang.org/grpc/status"
 )
 
 type watchServer struct {
@@ -140,8 +143,10 @@ func (ws *watchServer) Watch(stream pb.Watch_WatchServer) (err error) {
 	// deadlock when calling sws.close().
 	go func() {
 		if rerr := sws.recvLoop(); rerr != nil {
-			if stream.Context().Err() == context.Canceled {
-				plog.Debugf("failed to receive watch request from gRPC stream 11 (%q)", rerr.Error())
+			ev, _ := status.FromError(rerr)
+			code := ev.Code()
+			if code == codes.Canceled || code == codes.DeadlineExceeded {
+				plog.Debugf("failed to receive watch request from gRPC stream (%q)", rerr.Error())
 			} else {
 				plog.Warningf("failed to receive watch request from gRPC stream (%q)", rerr.Error())
 			}