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// Copyright 2016 The etcd Authors
//
// 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 clientv3
import (
"context"
"fmt"
"io"
pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
"google.golang.org/grpc"
)
type (
DefragmentResponse pb.DefragmentResponse
AlarmResponse pb.AlarmResponse
AlarmMember pb.AlarmMember
StatusResponse pb.StatusResponse
HashKVResponse pb.HashKVResponse
MoveLeaderResponse pb.MoveLeaderResponse
)
type Maintenance interface {
// AlarmList gets all active alarms.
AlarmList(ctx context.Context) (*AlarmResponse, error)
// AlarmDisarm disarms a given alarm.
AlarmDisarm(ctx context.Context, m *AlarmMember) (*AlarmResponse, error)
// Defragment releases wasted space from internal fragmentation on a given etcd member.
// Defragment is only needed when deleting a large number of keys and want to reclaim
// the resources.
// Defragment is an expensive operation. User should avoid defragmenting multiple members
// at the same time.
// To defragment multiple members in the cluster, user need to call defragment multiple
// times with different endpoints.
Defragment(ctx context.Context, endpoint string) (*DefragmentResponse, error)
// Status gets the status of the endpoint.
Status(ctx context.Context, endpoint string) (*StatusResponse, error)
// HashKV returns a hash of the KV state at the time of the RPC.
// If revision is zero, the hash is computed on all keys. If the revision
// is non-zero, the hash is computed on all keys at or below the given revision.
HashKV(ctx context.Context, endpoint string, rev int64) (*HashKVResponse, error)
// Snapshot provides a reader for a point-in-time snapshot of etcd.
// If the context "ctx" is canceled or timed out, reading from returned
// "io.ReadCloser" would error out (e.g. context.Canceled, context.DeadlineExceeded).
Snapshot(ctx context.Context) (io.ReadCloser, error)
// MoveLeader requests current leader to transfer its leadership to the transferee.
// Request must be made to the leader.
MoveLeader(ctx context.Context, transfereeID uint64) (*MoveLeaderResponse, error)
}
type maintenance struct {
dial func(endpoint string) (pb.MaintenanceClient, func(), error)
remote pb.MaintenanceClient
callOpts []grpc.CallOption
}
func NewMaintenance(c *Client) Maintenance {
api := &maintenance{
dial: func(endpoint string) (pb.MaintenanceClient, func(), error) {
conn, err := c.Dial(endpoint)
if err != nil {
return nil, nil, fmt.Errorf("failed to dial endpoint %s with maintenance client: %v", endpoint, err)
}
cancel := func() { conn.Close() }
return RetryMaintenanceClient(c, conn), cancel, nil
},
remote: RetryMaintenanceClient(c, c.conn),
}
if c != nil {
api.callOpts = c.callOpts
}
return api
}
func NewMaintenanceFromMaintenanceClient(remote pb.MaintenanceClient, c *Client) Maintenance {
api := &maintenance{
dial: func(string) (pb.MaintenanceClient, func(), error) {
return remote, func() {}, nil
},
remote: remote,
}
if c != nil {
api.callOpts = c.callOpts
}
return api
}
func (m *maintenance) AlarmList(ctx context.Context) (*AlarmResponse, error) {
req := &pb.AlarmRequest{
Action: pb.AlarmRequest_GET,
MemberID: 0, // all
Alarm: pb.AlarmType_NONE, // all
}
resp, err := m.remote.Alarm(ctx, req, m.callOpts...)
if err == nil {
return (*AlarmResponse)(resp), nil
}
return nil, toErr(ctx, err)
}
func (m *maintenance) AlarmDisarm(ctx context.Context, am *AlarmMember) (*AlarmResponse, error) {
req := &pb.AlarmRequest{
Action: pb.AlarmRequest_DEACTIVATE,
MemberID: am.MemberID,
Alarm: am.Alarm,
}
if req.MemberID == 0 && req.Alarm == pb.AlarmType_NONE {
ar, err := m.AlarmList(ctx)
if err != nil {
return nil, toErr(ctx, err)
}
ret := AlarmResponse{}
for _, am := range ar.Alarms {
dresp, derr := m.AlarmDisarm(ctx, (*AlarmMember)(am))
if derr != nil {
return nil, toErr(ctx, derr)
}
ret.Alarms = append(ret.Alarms, dresp.Alarms...)
}
return &ret, nil
}
resp, err := m.remote.Alarm(ctx, req, m.callOpts...)
if err == nil {
return (*AlarmResponse)(resp), nil
}
return nil, toErr(ctx, err)
}
func (m *maintenance) Defragment(ctx context.Context, endpoint string) (*DefragmentResponse, error) {
remote, cancel, err := m.dial(endpoint)
if err != nil {
return nil, toErr(ctx, err)
}
defer cancel()
resp, err := remote.Defragment(ctx, &pb.DefragmentRequest{}, m.callOpts...)
if err != nil {
return nil, toErr(ctx, err)
}
return (*DefragmentResponse)(resp), nil
}
func (m *maintenance) Status(ctx context.Context, endpoint string) (*StatusResponse, error) {
remote, cancel, err := m.dial(endpoint)
if err != nil {
return nil, toErr(ctx, err)
}
defer cancel()
resp, err := remote.Status(ctx, &pb.StatusRequest{}, m.callOpts...)
if err != nil {
return nil, toErr(ctx, err)
}
return (*StatusResponse)(resp), nil
}
func (m *maintenance) HashKV(ctx context.Context, endpoint string, rev int64) (*HashKVResponse, error) {
remote, cancel, err := m.dial(endpoint)
if err != nil {
return nil, toErr(ctx, err)
}
defer cancel()
resp, err := remote.HashKV(ctx, &pb.HashKVRequest{Revision: rev}, m.callOpts...)
if err != nil {
return nil, toErr(ctx, err)
}
return (*HashKVResponse)(resp), nil
}
func (m *maintenance) Snapshot(ctx context.Context) (io.ReadCloser, error) {
ss, err := m.remote.Snapshot(ctx, &pb.SnapshotRequest{}, append(m.callOpts, withMax(defaultStreamMaxRetries))...)
if err != nil {
return nil, toErr(ctx, err)
}
plog.Info("opened snapshot stream; downloading")
pr, pw := io.Pipe()
go func() {
for {
resp, err := ss.Recv()
if err != nil {
switch err {
case io.EOF:
plog.Info("completed snapshot read; closing")
default:
plog.Warningf("failed to receive from snapshot stream; closing (%v)", err)
}
pw.CloseWithError(err)
return
}
// can "resp == nil && err == nil"
// before we receive snapshot SHA digest?
// No, server sends EOF with an empty response
// after it sends SHA digest at the end
if _, werr := pw.Write(resp.Blob); werr != nil {
pw.CloseWithError(werr)
return
}
}
}()
return &snapshotReadCloser{ctx: ctx, ReadCloser: pr}, nil
}
type snapshotReadCloser struct {
ctx context.Context
io.ReadCloser
}
func (rc *snapshotReadCloser) Read(p []byte) (n int, err error) {
n, err = rc.ReadCloser.Read(p)
return n, toErr(rc.ctx, err)
}
func (m *maintenance) MoveLeader(ctx context.Context, transfereeID uint64) (*MoveLeaderResponse, error) {
resp, err := m.remote.MoveLeader(ctx, &pb.MoveLeaderRequest{TargetID: transfereeID}, m.callOpts...)
return (*MoveLeaderResponse)(resp), toErr(ctx, err)
}