1 // Copyright 2017 The etcd Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // Package naming provides: 16 // - subpackage endpoints: an abstraction layer to store and read endpoints 17 // information from etcd. 18 // - subpackage resolver: an etcd-backed gRPC resolver for discovering gRPC 19 // services based on the endpoints configuration 20 // 21 // To use, first import the packages: 22 // 23 // import ( 24 // "go.etcd.io/etcd/client/v3" 25 // "go.etcd.io/etcd/client/v3/naming/endpoints" 26 // "go.etcd.io/etcd/client/v3/naming/resolver" 27 // "google.golang.org/grpc" 28 // ) 29 // 30 // First, register new endpoint addresses for a service: 31 // 32 // func etcdAdd(c *clientv3.Client, service, addr string) error { 33 // em := endpoints.NewManager(c, service) 34 // return em.AddEndpoint(c.Ctx(), service+"/"+addr, endpoints.Endpoint{Addr:addr}); 35 // } 36 // 37 // Dial an RPC service using the etcd gRPC resolver and a gRPC Balancer: 38 // 39 // func etcdDial(c *clientv3.Client, service string) (*grpc.ClientConn, error) { 40 // etcdResolver, err := resolver.NewBuilder(c); 41 // if err { return nil, err } 42 // return grpc.Dial("etcd:///" + service, grpc.WithResolvers(etcdResolver)) 43 // } 44 // 45 // Optionally, force delete an endpoint: 46 // 47 // func etcdDelete(c *clientv3, service, addr string) error { 48 // em := endpoints.NewManager(c, service) 49 // return em.DeleteEndpoint(c.Ctx(), service+"/"+addr) 50 // } 51 // 52 // Or register an expiring endpoint with a lease: 53 // 54 // func etcdAdd(c *clientv3.Client, lid clientv3.LeaseID, service, addr string) error { 55 // em := endpoints.NewManager(c, service) 56 // return em.AddEndpoint(c.Ctx(), service+"/"+addr, endpoints.Endpoint{Addr:addr}, clientv3.WithLease(lid)); 57 // } 58 package naming 59