ceph-csi/vendor/go.etcd.io/etcd/client/v3/client.go

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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"
"errors"
"fmt"
"strconv"
"strings"
"sync"
"time"
"go.etcd.io/etcd/api/v3/v3rpc/rpctypes"
"go.etcd.io/etcd/client/pkg/v3/logutil"
"go.etcd.io/etcd/client/v3/credentials"
"go.etcd.io/etcd/client/v3/internal/endpoint"
"go.etcd.io/etcd/client/v3/internal/resolver"
"go.uber.org/zap"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
grpccredentials "google.golang.org/grpc/credentials"
"google.golang.org/grpc/keepalive"
"google.golang.org/grpc/status"
)
var (
ErrNoAvailableEndpoints = errors.New("etcdclient: no available endpoints")
ErrOldCluster = errors.New("etcdclient: old cluster version")
)
// Client provides and manages an etcd v3 client session.
type Client struct {
Cluster
KV
Lease
Watcher
Auth
Maintenance
conn *grpc.ClientConn
cfg Config
creds grpccredentials.TransportCredentials
resolver *resolver.EtcdManualResolver
mu *sync.RWMutex
ctx context.Context
cancel context.CancelFunc
// Username is a user name for authentication.
Username string
// Password is a password for authentication.
Password string
authTokenBundle credentials.Bundle
callOpts []grpc.CallOption
lgMu *sync.RWMutex
lg *zap.Logger
}
// New creates a new etcdv3 client from a given configuration.
func New(cfg Config) (*Client, error) {
if len(cfg.Endpoints) == 0 {
return nil, ErrNoAvailableEndpoints
}
return newClient(&cfg)
}
// NewCtxClient creates a client with a context but no underlying grpc
// connection. This is useful for embedded cases that override the
// service interface implementations and do not need connection management.
func NewCtxClient(ctx context.Context, opts ...Option) *Client {
cctx, cancel := context.WithCancel(ctx)
c := &Client{ctx: cctx, cancel: cancel, lgMu: new(sync.RWMutex)}
for _, opt := range opts {
opt(c)
}
if c.lg == nil {
c.lg = zap.NewNop()
}
return c
}
// Option is a function type that can be passed as argument to NewCtxClient to configure client
type Option func(*Client)
// NewFromURL creates a new etcdv3 client from a URL.
func NewFromURL(url string) (*Client, error) {
return New(Config{Endpoints: []string{url}})
}
// NewFromURLs creates a new etcdv3 client from URLs.
func NewFromURLs(urls []string) (*Client, error) {
return New(Config{Endpoints: urls})
}
// WithZapLogger is a NewCtxClient option that overrides the logger
func WithZapLogger(lg *zap.Logger) Option {
return func(c *Client) {
c.lg = lg
}
}
// WithLogger overrides the logger.
//
// Deprecated: Please use WithZapLogger or Logger field in clientv3.Config
//
// Does not changes grpcLogger, that can be explicitly configured
// using grpc_zap.ReplaceGrpcLoggerV2(..) method.
func (c *Client) WithLogger(lg *zap.Logger) *Client {
c.lgMu.Lock()
c.lg = lg
c.lgMu.Unlock()
return c
}
// GetLogger gets the logger.
// NOTE: This method is for internal use of etcd-client library and should not be used as general-purpose logger.
func (c *Client) GetLogger() *zap.Logger {
c.lgMu.RLock()
l := c.lg
c.lgMu.RUnlock()
return l
}
// Close shuts down the client's etcd connections.
func (c *Client) Close() error {
c.cancel()
if c.Watcher != nil {
c.Watcher.Close()
}
if c.Lease != nil {
c.Lease.Close()
}
if c.conn != nil {
return toErr(c.ctx, c.conn.Close())
}
return c.ctx.Err()
}
// Ctx is a context for "out of band" messages (e.g., for sending
// "clean up" message when another context is canceled). It is
// canceled on client Close().
func (c *Client) Ctx() context.Context { return c.ctx }
// Endpoints lists the registered endpoints for the client.
func (c *Client) Endpoints() []string {
// copy the slice; protect original endpoints from being changed
c.mu.RLock()
defer c.mu.RUnlock()
eps := make([]string, len(c.cfg.Endpoints))
copy(eps, c.cfg.Endpoints)
return eps
}
// SetEndpoints updates client's endpoints.
func (c *Client) SetEndpoints(eps ...string) {
c.mu.Lock()
defer c.mu.Unlock()
c.cfg.Endpoints = eps
c.resolver.SetEndpoints(eps)
}
// Sync synchronizes client's endpoints with the known endpoints from the etcd membership.
func (c *Client) Sync(ctx context.Context) error {
mresp, err := c.MemberList(ctx)
if err != nil {
return err
}
var eps []string
for _, m := range mresp.Members {
if len(m.Name) != 0 && !m.IsLearner {
eps = append(eps, m.ClientURLs...)
}
}
c.SetEndpoints(eps...)
return nil
}
func (c *Client) autoSync() {
if c.cfg.AutoSyncInterval == time.Duration(0) {
return
}
for {
select {
case <-c.ctx.Done():
return
case <-time.After(c.cfg.AutoSyncInterval):
ctx, cancel := context.WithTimeout(c.ctx, 5*time.Second)
err := c.Sync(ctx)
cancel()
if err != nil && err != c.ctx.Err() {
c.lg.Info("Auto sync endpoints failed.", zap.Error(err))
}
}
}
}
// dialSetupOpts gives the dial opts prior to any authentication.
func (c *Client) dialSetupOpts(creds grpccredentials.TransportCredentials, dopts ...grpc.DialOption) (opts []grpc.DialOption, err error) {
if c.cfg.DialKeepAliveTime > 0 {
params := keepalive.ClientParameters{
Time: c.cfg.DialKeepAliveTime,
Timeout: c.cfg.DialKeepAliveTimeout,
PermitWithoutStream: c.cfg.PermitWithoutStream,
}
opts = append(opts, grpc.WithKeepaliveParams(params))
}
opts = append(opts, dopts...)
if creds != nil {
opts = append(opts, grpc.WithTransportCredentials(creds))
} else {
opts = append(opts, grpc.WithInsecure())
}
// Interceptor retry and backoff.
// TODO: Replace all of clientv3/retry.go with RetryPolicy:
// https://github.com/grpc/grpc-proto/blob/cdd9ed5c3d3f87aef62f373b93361cf7bddc620d/grpc/service_config/service_config.proto#L130
rrBackoff := withBackoff(c.roundRobinQuorumBackoff(defaultBackoffWaitBetween, defaultBackoffJitterFraction))
opts = append(opts,
// Disable stream retry by default since go-grpc-middleware/retry does not support client streams.
// Streams that are safe to retry are enabled individually.
grpc.WithStreamInterceptor(c.streamClientInterceptor(withMax(0), rrBackoff)),
grpc.WithUnaryInterceptor(c.unaryClientInterceptor(withMax(defaultUnaryMaxRetries), rrBackoff)),
)
return opts, nil
}
// Dial connects to a single endpoint using the client's config.
func (c *Client) Dial(ep string) (*grpc.ClientConn, error) {
creds := c.credentialsForEndpoint(ep)
// Using ad-hoc created resolver, to guarantee only explicitly given
// endpoint is used.
return c.dial(creds, grpc.WithResolvers(resolver.New(ep)))
}
func (c *Client) getToken(ctx context.Context) error {
var err error // return last error in a case of fail
if c.Username == "" || c.Password == "" {
return nil
}
resp, err := c.Auth.Authenticate(ctx, c.Username, c.Password)
if err != nil {
if err == rpctypes.ErrAuthNotEnabled {
return nil
}
return err
}
c.authTokenBundle.UpdateAuthToken(resp.Token)
return nil
}
// dialWithBalancer dials the client's current load balanced resolver group. The scheme of the host
// of the provided endpoint determines the scheme used for all endpoints of the client connection.
func (c *Client) dialWithBalancer(dopts ...grpc.DialOption) (*grpc.ClientConn, error) {
creds := c.credentialsForEndpoint(c.Endpoints()[0])
opts := append(dopts, grpc.WithResolvers(c.resolver))
return c.dial(creds, opts...)
}
// dial configures and dials any grpc balancer target.
func (c *Client) dial(creds grpccredentials.TransportCredentials, dopts ...grpc.DialOption) (*grpc.ClientConn, error) {
opts, err := c.dialSetupOpts(creds, dopts...)
if err != nil {
return nil, fmt.Errorf("failed to configure dialer: %v", err)
}
if c.authTokenBundle != nil {
opts = append(opts, grpc.WithPerRPCCredentials(c.authTokenBundle.PerRPCCredentials()))
}
opts = append(opts, c.cfg.DialOptions...)
dctx := c.ctx
if c.cfg.DialTimeout > 0 {
var cancel context.CancelFunc
dctx, cancel = context.WithTimeout(c.ctx, c.cfg.DialTimeout)
defer cancel() // TODO: Is this right for cases where grpc.WithBlock() is not set on the dial options?
}
target := fmt.Sprintf("%s://%p/%s", resolver.Schema, c, authority(c.Endpoints()[0]))
conn, err := grpc.DialContext(dctx, target, opts...)
if err != nil {
return nil, err
}
return conn, nil
}
func authority(endpoint string) string {
spl := strings.SplitN(endpoint, "://", 2)
if len(spl) < 2 {
if strings.HasPrefix(endpoint, "unix:") {
return endpoint[len("unix:"):]
}
if strings.HasPrefix(endpoint, "unixs:") {
return endpoint[len("unixs:"):]
}
return endpoint
}
return spl[1]
}
func (c *Client) credentialsForEndpoint(ep string) grpccredentials.TransportCredentials {
r := endpoint.RequiresCredentials(ep)
switch r {
case endpoint.CREDS_DROP:
return nil
case endpoint.CREDS_OPTIONAL:
return c.creds
case endpoint.CREDS_REQUIRE:
if c.creds != nil {
return c.creds
}
return credentials.NewBundle(credentials.Config{}).TransportCredentials()
default:
panic(fmt.Errorf("unsupported CredsRequirement: %v", r))
}
}
func newClient(cfg *Config) (*Client, error) {
if cfg == nil {
cfg = &Config{}
}
var creds grpccredentials.TransportCredentials
if cfg.TLS != nil {
creds = credentials.NewBundle(credentials.Config{TLSConfig: cfg.TLS}).TransportCredentials()
}
// use a temporary skeleton client to bootstrap first connection
baseCtx := context.TODO()
if cfg.Context != nil {
baseCtx = cfg.Context
}
ctx, cancel := context.WithCancel(baseCtx)
client := &Client{
conn: nil,
cfg: *cfg,
creds: creds,
ctx: ctx,
cancel: cancel,
mu: new(sync.RWMutex),
callOpts: defaultCallOpts,
lgMu: new(sync.RWMutex),
}
var err error
if cfg.Logger != nil {
client.lg = cfg.Logger
} else if cfg.LogConfig != nil {
client.lg, err = cfg.LogConfig.Build()
} else {
client.lg, err = logutil.CreateDefaultZapLogger(etcdClientDebugLevel())
if client.lg != nil {
client.lg = client.lg.Named("etcd-client")
}
}
if err != nil {
return nil, err
}
if cfg.Username != "" && cfg.Password != "" {
client.Username = cfg.Username
client.Password = cfg.Password
client.authTokenBundle = credentials.NewBundle(credentials.Config{})
}
if cfg.MaxCallSendMsgSize > 0 || cfg.MaxCallRecvMsgSize > 0 {
if cfg.MaxCallRecvMsgSize > 0 && cfg.MaxCallSendMsgSize > cfg.MaxCallRecvMsgSize {
return nil, fmt.Errorf("gRPC message recv limit (%d bytes) must be greater than send limit (%d bytes)", cfg.MaxCallRecvMsgSize, cfg.MaxCallSendMsgSize)
}
callOpts := []grpc.CallOption{
defaultWaitForReady,
defaultMaxCallSendMsgSize,
defaultMaxCallRecvMsgSize,
}
if cfg.MaxCallSendMsgSize > 0 {
callOpts[1] = grpc.MaxCallSendMsgSize(cfg.MaxCallSendMsgSize)
}
if cfg.MaxCallRecvMsgSize > 0 {
callOpts[2] = grpc.MaxCallRecvMsgSize(cfg.MaxCallRecvMsgSize)
}
client.callOpts = callOpts
}
client.resolver = resolver.New(cfg.Endpoints...)
if len(cfg.Endpoints) < 1 {
client.cancel()
return nil, fmt.Errorf("at least one Endpoint is required in client config")
}
// Use a provided endpoint target so that for https:// without any tls config given, then
// grpc will assume the certificate server name is the endpoint host.
conn, err := client.dialWithBalancer()
if err != nil {
client.cancel()
client.resolver.Close()
// TODO: Error like `fmt.Errorf(dialing [%s] failed: %v, strings.Join(cfg.Endpoints, ";"), err)` would help with debugging a lot.
return nil, err
}
client.conn = conn
client.Cluster = NewCluster(client)
client.KV = NewKV(client)
client.Lease = NewLease(client)
client.Watcher = NewWatcher(client)
client.Auth = NewAuth(client)
client.Maintenance = NewMaintenance(client)
//get token with established connection
ctx, cancel = client.ctx, func() {}
if client.cfg.DialTimeout > 0 {
ctx, cancel = context.WithTimeout(ctx, client.cfg.DialTimeout)
}
err = client.getToken(ctx)
if err != nil {
client.Close()
cancel()
//TODO: Consider fmt.Errorf("communicating with [%s] failed: %v", strings.Join(cfg.Endpoints, ";"), err)
return nil, err
}
cancel()
if cfg.RejectOldCluster {
if err := client.checkVersion(); err != nil {
client.Close()
return nil, err
}
}
go client.autoSync()
return client, nil
}
// roundRobinQuorumBackoff retries against quorum between each backoff.
// This is intended for use with a round robin load balancer.
func (c *Client) roundRobinQuorumBackoff(waitBetween time.Duration, jitterFraction float64) backoffFunc {
return func(attempt uint) time.Duration {
// after each round robin across quorum, backoff for our wait between duration
n := uint(len(c.Endpoints()))
quorum := (n/2 + 1)
if attempt%quorum == 0 {
c.lg.Debug("backoff", zap.Uint("attempt", attempt), zap.Uint("quorum", quorum), zap.Duration("waitBetween", waitBetween), zap.Float64("jitterFraction", jitterFraction))
return jitterUp(waitBetween, jitterFraction)
}
c.lg.Debug("backoff skipped", zap.Uint("attempt", attempt), zap.Uint("quorum", quorum))
return 0
}
}
func (c *Client) checkVersion() (err error) {
var wg sync.WaitGroup
eps := c.Endpoints()
errc := make(chan error, len(eps))
ctx, cancel := context.WithCancel(c.ctx)
if c.cfg.DialTimeout > 0 {
cancel()
ctx, cancel = context.WithTimeout(c.ctx, c.cfg.DialTimeout)
}
wg.Add(len(eps))
for _, ep := range eps {
// if cluster is current, any endpoint gives a recent version
go func(e string) {
defer wg.Done()
resp, rerr := c.Status(ctx, e)
if rerr != nil {
errc <- rerr
return
}
vs := strings.Split(resp.Version, ".")
maj, min := 0, 0
if len(vs) >= 2 {
var serr error
if maj, serr = strconv.Atoi(vs[0]); serr != nil {
errc <- serr
return
}
if min, serr = strconv.Atoi(vs[1]); serr != nil {
errc <- serr
return
}
}
if maj < 3 || (maj == 3 && min < 2) {
rerr = ErrOldCluster
}
errc <- rerr
}(ep)
}
// wait for success
for range eps {
if err = <-errc; err == nil {
break
}
}
cancel()
wg.Wait()
return err
}
// ActiveConnection returns the current in-use connection
func (c *Client) ActiveConnection() *grpc.ClientConn { return c.conn }
// isHaltErr returns true if the given error and context indicate no forward
// progress can be made, even after reconnecting.
func isHaltErr(ctx context.Context, err error) bool {
if ctx != nil && ctx.Err() != nil {
return true
}
if err == nil {
return false
}
ev, _ := status.FromError(err)
// Unavailable codes mean the system will be right back.
// (e.g., can't connect, lost leader)
// Treat Internal codes as if something failed, leaving the
// system in an inconsistent state, but retrying could make progress.
// (e.g., failed in middle of send, corrupted frame)
// TODO: are permanent Internal errors possible from grpc?
return ev.Code() != codes.Unavailable && ev.Code() != codes.Internal
}
// isUnavailableErr returns true if the given error is an unavailable error
func isUnavailableErr(ctx context.Context, err error) bool {
if ctx != nil && ctx.Err() != nil {
return false
}
if err == nil {
return false
}
ev, ok := status.FromError(err)
if ok {
// Unavailable codes mean the system will be right back.
// (e.g., can't connect, lost leader)
return ev.Code() == codes.Unavailable
}
return false
}
func toErr(ctx context.Context, err error) error {
if err == nil {
return nil
}
err = rpctypes.Error(err)
if _, ok := err.(rpctypes.EtcdError); ok {
return err
}
if ev, ok := status.FromError(err); ok {
code := ev.Code()
switch code {
case codes.DeadlineExceeded:
fallthrough
case codes.Canceled:
if ctx.Err() != nil {
err = ctx.Err()
}
}
}
return err
}
func canceledByCaller(stopCtx context.Context, err error) bool {
if stopCtx.Err() == nil || err == nil {
return false
}
return err == context.Canceled || err == context.DeadlineExceeded
}
// IsConnCanceled returns true, if error is from a closed gRPC connection.
// ref. https://github.com/grpc/grpc-go/pull/1854
func IsConnCanceled(err error) bool {
if err == nil {
return false
}
// >= gRPC v1.23.x
s, ok := status.FromError(err)
if ok {
// connection is canceled or server has already closed the connection
return s.Code() == codes.Canceled || s.Message() == "transport is closing"
}
// >= gRPC v1.10.x
if err == context.Canceled {
return true
}
// <= gRPC v1.7.x returns 'errors.New("grpc: the client connection is closing")'
return strings.Contains(err.Error(), "grpc: the client connection is closing")
}