etcd-io__etcd/etcdserver/api/v3rpc/interceptor.go

// Copyright 2016 CoreOS, Inc.
//
// 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 v3rpc

import (
	"strings"
	"time"

	"github.com/coreos/etcd/etcdserver"
	"github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes"
	"github.com/coreos/etcd/pkg/types"
	"github.com/coreos/etcd/raft"

	"golang.org/x/net/context"
	"google.golang.org/grpc"
	"google.golang.org/grpc/metadata"
)

func newUnaryInterceptor(s *etcdserver.EtcdServer) grpc.UnaryServerInterceptor {
	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
		md, ok := metadata.FromContext(ctx)
		if ok {
			if ks := md[rpctypes.MetadataRequireLeaderKey]; len(ks) > 0 && ks[0] == rpctypes.MetadataHasLeader {
				if s.Leader() == types.ID(raft.None) {
					return nil, rpctypes.ErrGRPCNoLeader
				}
			}
		}
		return metricsUnaryInterceptor(ctx, req, info, handler)
	}
}

func metricsUnaryInterceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
	service, method := splitMethodName(info.FullMethod)
	receivedCounter.WithLabelValues(service, method).Inc()

	start := time.Now()
	resp, err = handler(ctx, req)
	if err != nil {
		failedCounter.WithLabelValues(service, method, grpc.Code(err).String()).Inc()
	}
	handlingDuration.WithLabelValues(service, method).Observe(time.Since(start).Seconds())

	return resp, err
}

func metricsStreamInterceptor(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
	service, method := splitMethodName(info.FullMethod)
	receivedCounter.WithLabelValues(service, method).Inc()

	err := handler(srv, ss)
	if err != nil {
		failedCounter.WithLabelValues(service, method, grpc.Code(err).String()).Inc()
	}

	return err
}

func splitMethodName(fullMethodName string) (string, string) {
	fullMethodName = strings.TrimPrefix(fullMethodName, "/") // remove leading slash
	if i := strings.Index(fullMethodName, "/"); i >= 0 {
		return fullMethodName[:i], fullMethodName[i+1:]
	}
	return "unknown", "unknown"
}