2016-05-13 06:50:58 +03:00
|
|
|
// Copyright 2016 The etcd Authors
|
2016-02-23 03:39:05 +03:00
|
|
|
//
|
|
|
|
// 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.
|
|
|
|
|
2016-03-20 00:04:45 +03:00
|
|
|
// Package clientv3 implements the official Go etcd client for v3.
|
2016-02-23 03:39:05 +03:00
|
|
|
//
|
|
|
|
// Create client using `clientv3.New`:
|
|
|
|
//
|
2017-11-29 21:53:54 +03:00
|
|
|
// // expect dial time-out on ipv4 blackhole
|
|
|
|
// _, err := clientv3.New(clientv3.Config{
|
|
|
|
// Endpoints: []string{"http://254.0.0.1:12345"},
|
|
|
|
// DialTimeout: 2 * time.Second
|
|
|
|
// })
|
2017-11-30 01:14:15 +03:00
|
|
|
//
|
|
|
|
// // etcd clientv3 >= v3.2.10, grpc/grpc-go >= v1.7.3
|
|
|
|
// if err == context.DeadlineExceeded {
|
|
|
|
// // handle errors
|
|
|
|
// }
|
|
|
|
//
|
|
|
|
// // etcd clientv3 <= v3.2.9, grpc/grpc-go <= v1.2.1
|
2017-11-29 21:53:54 +03:00
|
|
|
// if err == grpc.ErrClientConnTimeout {
|
|
|
|
// // handle errors
|
|
|
|
// }
|
|
|
|
//
|
2016-02-23 03:39:05 +03:00
|
|
|
// cli, err := clientv3.New(clientv3.Config{
|
2016-03-22 00:21:09 +03:00
|
|
|
// Endpoints: []string{"localhost:2379", "localhost:22379", "localhost:32379"},
|
2016-02-23 03:39:05 +03:00
|
|
|
// DialTimeout: 5 * time.Second,
|
|
|
|
// })
|
|
|
|
// if err != nil {
|
|
|
|
// // handle error!
|
|
|
|
// }
|
|
|
|
// defer cli.Close()
|
|
|
|
//
|
|
|
|
// Make sure to close the client after using it. If the client is not closed, the
|
|
|
|
// connection will have leaky goroutines.
|
|
|
|
//
|
2017-09-04 13:09:32 +03:00
|
|
|
// To specify a client request timeout, wrap the context with context.WithTimeout:
|
2016-02-23 03:39:05 +03:00
|
|
|
//
|
|
|
|
// ctx, cancel := context.WithTimeout(context.Background(), timeout)
|
|
|
|
// resp, err := kvc.Put(ctx, "sample_key", "sample_value")
|
|
|
|
// cancel()
|
|
|
|
// if err != nil {
|
|
|
|
// // handle error!
|
|
|
|
// }
|
|
|
|
// // use the response
|
|
|
|
//
|
2016-03-29 19:28:53 +03:00
|
|
|
// The Client has internal state (watchers and leases), so Clients should be reused instead of created as needed.
|
|
|
|
// Clients are safe for concurrent use by multiple goroutines.
|
|
|
|
//
|
2017-11-29 21:53:54 +03:00
|
|
|
// etcd client returns 3 types of errors:
|
2016-03-01 00:54:35 +03:00
|
|
|
//
|
|
|
|
// 1. context error: canceled or deadline exceeded.
|
2017-11-29 21:53:54 +03:00
|
|
|
// 2. gRPC status error: e.g. when clock drifts in server-side before client's context deadline exceeded.
|
|
|
|
// 3. gRPC error: see https://github.com/coreos/etcd/blob/master/etcdserver/api/v3rpc/rpctypes/error.go
|
2016-03-01 00:54:35 +03:00
|
|
|
//
|
|
|
|
// Here is the example code to handle client errors:
|
|
|
|
//
|
|
|
|
// resp, err := kvc.Put(ctx, "", "")
|
|
|
|
// if err != nil {
|
|
|
|
// if err == context.Canceled {
|
|
|
|
// // ctx is canceled by another routine
|
|
|
|
// } else if err == context.DeadlineExceeded {
|
|
|
|
// // ctx is attached with a deadline and it exceeded
|
2017-11-28 01:06:42 +03:00
|
|
|
// } else if ev, ok := status.FromError(err); ok {
|
|
|
|
// code := ev.Code()
|
|
|
|
// if code == codes.DeadlineExceeded {
|
|
|
|
// // server-side context might have timed-out first (due to clock skew)
|
|
|
|
// // while original client-side context is not timed-out yet
|
|
|
|
// }
|
2016-03-01 00:54:35 +03:00
|
|
|
// } else if verr, ok := err.(*v3rpc.ErrEmptyKey); ok {
|
|
|
|
// // process (verr.Errors)
|
|
|
|
// } else {
|
|
|
|
// // bad cluster endpoints, which are not etcd servers
|
|
|
|
// }
|
|
|
|
// }
|
2016-02-23 03:39:05 +03:00
|
|
|
//
|
2017-11-29 21:53:54 +03:00
|
|
|
// go func() { cli.Close() }()
|
|
|
|
// _, err := kvc.Get(ctx, "a")
|
|
|
|
// if err != nil {
|
|
|
|
// if err == context.Canceled {
|
|
|
|
// // grpc balancer calls 'Get' with an inflight client.Close
|
|
|
|
// } else if err == grpc.ErrClientConnClosing {
|
|
|
|
// // grpc balancer calls 'Get' after client.Close.
|
|
|
|
// }
|
|
|
|
// }
|
|
|
|
//
|
2016-02-23 03:39:05 +03:00
|
|
|
package clientv3
|