mirror of
https://github.com/k3s-io/kubernetes.git
synced 2025-10-30 21:30:16 +00:00
329 lines
8.5 KiB
Go
329 lines
8.5 KiB
Go
/*
|
|
*
|
|
* Copyright 2017 gRPC 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 grpc
|
|
|
|
import (
|
|
"strings"
|
|
"sync"
|
|
|
|
"golang.org/x/net/context"
|
|
"google.golang.org/grpc/balancer"
|
|
"google.golang.org/grpc/codes"
|
|
"google.golang.org/grpc/connectivity"
|
|
"google.golang.org/grpc/grpclog"
|
|
"google.golang.org/grpc/resolver"
|
|
"google.golang.org/grpc/status"
|
|
)
|
|
|
|
type balancerWrapperBuilder struct {
|
|
b Balancer // The v1 balancer.
|
|
}
|
|
|
|
func (bwb *balancerWrapperBuilder) Build(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer {
|
|
targetAddr := cc.Target()
|
|
targetSplitted := strings.Split(targetAddr, ":///")
|
|
if len(targetSplitted) >= 2 {
|
|
targetAddr = targetSplitted[1]
|
|
}
|
|
|
|
bwb.b.Start(targetAddr, BalancerConfig{
|
|
DialCreds: opts.DialCreds,
|
|
Dialer: opts.Dialer,
|
|
})
|
|
_, pickfirst := bwb.b.(*pickFirst)
|
|
bw := &balancerWrapper{
|
|
balancer: bwb.b,
|
|
pickfirst: pickfirst,
|
|
cc: cc,
|
|
targetAddr: targetAddr,
|
|
startCh: make(chan struct{}),
|
|
conns: make(map[resolver.Address]balancer.SubConn),
|
|
connSt: make(map[balancer.SubConn]*scState),
|
|
csEvltr: &balancer.ConnectivityStateEvaluator{},
|
|
state: connectivity.Idle,
|
|
}
|
|
cc.UpdateBalancerState(connectivity.Idle, bw)
|
|
go bw.lbWatcher()
|
|
return bw
|
|
}
|
|
|
|
func (bwb *balancerWrapperBuilder) Name() string {
|
|
return "wrapper"
|
|
}
|
|
|
|
type scState struct {
|
|
addr Address // The v1 address type.
|
|
s connectivity.State
|
|
down func(error)
|
|
}
|
|
|
|
type balancerWrapper struct {
|
|
balancer Balancer // The v1 balancer.
|
|
pickfirst bool
|
|
|
|
cc balancer.ClientConn
|
|
targetAddr string // Target without the scheme.
|
|
|
|
mu sync.Mutex
|
|
conns map[resolver.Address]balancer.SubConn
|
|
connSt map[balancer.SubConn]*scState
|
|
// This channel is closed when handling the first resolver result.
|
|
// lbWatcher blocks until this is closed, to avoid race between
|
|
// - NewSubConn is created, cc wants to notify balancer of state changes;
|
|
// - Build hasn't return, cc doesn't have access to balancer.
|
|
startCh chan struct{}
|
|
|
|
// To aggregate the connectivity state.
|
|
csEvltr *balancer.ConnectivityStateEvaluator
|
|
state connectivity.State
|
|
}
|
|
|
|
// lbWatcher watches the Notify channel of the balancer and manages
|
|
// connections accordingly.
|
|
func (bw *balancerWrapper) lbWatcher() {
|
|
<-bw.startCh
|
|
notifyCh := bw.balancer.Notify()
|
|
if notifyCh == nil {
|
|
// There's no resolver in the balancer. Connect directly.
|
|
a := resolver.Address{
|
|
Addr: bw.targetAddr,
|
|
Type: resolver.Backend,
|
|
}
|
|
sc, err := bw.cc.NewSubConn([]resolver.Address{a}, balancer.NewSubConnOptions{})
|
|
if err != nil {
|
|
grpclog.Warningf("Error creating connection to %v. Err: %v", a, err)
|
|
} else {
|
|
bw.mu.Lock()
|
|
bw.conns[a] = sc
|
|
bw.connSt[sc] = &scState{
|
|
addr: Address{Addr: bw.targetAddr},
|
|
s: connectivity.Idle,
|
|
}
|
|
bw.mu.Unlock()
|
|
sc.Connect()
|
|
}
|
|
return
|
|
}
|
|
|
|
for addrs := range notifyCh {
|
|
grpclog.Infof("balancerWrapper: got update addr from Notify: %v\n", addrs)
|
|
if bw.pickfirst {
|
|
var (
|
|
oldA resolver.Address
|
|
oldSC balancer.SubConn
|
|
)
|
|
bw.mu.Lock()
|
|
for oldA, oldSC = range bw.conns {
|
|
break
|
|
}
|
|
bw.mu.Unlock()
|
|
if len(addrs) <= 0 {
|
|
if oldSC != nil {
|
|
// Teardown old sc.
|
|
bw.mu.Lock()
|
|
delete(bw.conns, oldA)
|
|
delete(bw.connSt, oldSC)
|
|
bw.mu.Unlock()
|
|
bw.cc.RemoveSubConn(oldSC)
|
|
}
|
|
continue
|
|
}
|
|
|
|
var newAddrs []resolver.Address
|
|
for _, a := range addrs {
|
|
newAddr := resolver.Address{
|
|
Addr: a.Addr,
|
|
Type: resolver.Backend, // All addresses from balancer are all backends.
|
|
ServerName: "",
|
|
Metadata: a.Metadata,
|
|
}
|
|
newAddrs = append(newAddrs, newAddr)
|
|
}
|
|
if oldSC == nil {
|
|
// Create new sc.
|
|
sc, err := bw.cc.NewSubConn(newAddrs, balancer.NewSubConnOptions{})
|
|
if err != nil {
|
|
grpclog.Warningf("Error creating connection to %v. Err: %v", newAddrs, err)
|
|
} else {
|
|
bw.mu.Lock()
|
|
// For pickfirst, there should be only one SubConn, so the
|
|
// address doesn't matter. All states updating (up and down)
|
|
// and picking should all happen on that only SubConn.
|
|
bw.conns[resolver.Address{}] = sc
|
|
bw.connSt[sc] = &scState{
|
|
addr: addrs[0], // Use the first address.
|
|
s: connectivity.Idle,
|
|
}
|
|
bw.mu.Unlock()
|
|
sc.Connect()
|
|
}
|
|
} else {
|
|
bw.mu.Lock()
|
|
bw.connSt[oldSC].addr = addrs[0]
|
|
bw.mu.Unlock()
|
|
oldSC.UpdateAddresses(newAddrs)
|
|
}
|
|
} else {
|
|
var (
|
|
add []resolver.Address // Addresses need to setup connections.
|
|
del []balancer.SubConn // Connections need to tear down.
|
|
)
|
|
resAddrs := make(map[resolver.Address]Address)
|
|
for _, a := range addrs {
|
|
resAddrs[resolver.Address{
|
|
Addr: a.Addr,
|
|
Type: resolver.Backend, // All addresses from balancer are all backends.
|
|
ServerName: "",
|
|
Metadata: a.Metadata,
|
|
}] = a
|
|
}
|
|
bw.mu.Lock()
|
|
for a := range resAddrs {
|
|
if _, ok := bw.conns[a]; !ok {
|
|
add = append(add, a)
|
|
}
|
|
}
|
|
for a, c := range bw.conns {
|
|
if _, ok := resAddrs[a]; !ok {
|
|
del = append(del, c)
|
|
delete(bw.conns, a)
|
|
// Keep the state of this sc in bw.connSt until its state becomes Shutdown.
|
|
}
|
|
}
|
|
bw.mu.Unlock()
|
|
for _, a := range add {
|
|
sc, err := bw.cc.NewSubConn([]resolver.Address{a}, balancer.NewSubConnOptions{})
|
|
if err != nil {
|
|
grpclog.Warningf("Error creating connection to %v. Err: %v", a, err)
|
|
} else {
|
|
bw.mu.Lock()
|
|
bw.conns[a] = sc
|
|
bw.connSt[sc] = &scState{
|
|
addr: resAddrs[a],
|
|
s: connectivity.Idle,
|
|
}
|
|
bw.mu.Unlock()
|
|
sc.Connect()
|
|
}
|
|
}
|
|
for _, c := range del {
|
|
bw.cc.RemoveSubConn(c)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func (bw *balancerWrapper) HandleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
|
|
bw.mu.Lock()
|
|
defer bw.mu.Unlock()
|
|
scSt, ok := bw.connSt[sc]
|
|
if !ok {
|
|
return
|
|
}
|
|
if s == connectivity.Idle {
|
|
sc.Connect()
|
|
}
|
|
oldS := scSt.s
|
|
scSt.s = s
|
|
if oldS != connectivity.Ready && s == connectivity.Ready {
|
|
scSt.down = bw.balancer.Up(scSt.addr)
|
|
} else if oldS == connectivity.Ready && s != connectivity.Ready {
|
|
if scSt.down != nil {
|
|
scSt.down(errConnClosing)
|
|
}
|
|
}
|
|
sa := bw.csEvltr.RecordTransition(oldS, s)
|
|
if bw.state != sa {
|
|
bw.state = sa
|
|
}
|
|
bw.cc.UpdateBalancerState(bw.state, bw)
|
|
if s == connectivity.Shutdown {
|
|
// Remove state for this sc.
|
|
delete(bw.connSt, sc)
|
|
}
|
|
}
|
|
|
|
func (bw *balancerWrapper) HandleResolvedAddrs([]resolver.Address, error) {
|
|
bw.mu.Lock()
|
|
defer bw.mu.Unlock()
|
|
select {
|
|
case <-bw.startCh:
|
|
default:
|
|
close(bw.startCh)
|
|
}
|
|
// There should be a resolver inside the balancer.
|
|
// All updates here, if any, are ignored.
|
|
}
|
|
|
|
func (bw *balancerWrapper) Close() {
|
|
bw.mu.Lock()
|
|
defer bw.mu.Unlock()
|
|
select {
|
|
case <-bw.startCh:
|
|
default:
|
|
close(bw.startCh)
|
|
}
|
|
bw.balancer.Close()
|
|
}
|
|
|
|
// The picker is the balancerWrapper itself.
|
|
// Pick should never return ErrNoSubConnAvailable.
|
|
// It either blocks or returns error, consistent with v1 balancer Get().
|
|
func (bw *balancerWrapper) Pick(ctx context.Context, opts balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
|
|
failfast := true // Default failfast is true.
|
|
if ss, ok := rpcInfoFromContext(ctx); ok {
|
|
failfast = ss.failfast
|
|
}
|
|
a, p, err := bw.balancer.Get(ctx, BalancerGetOptions{BlockingWait: !failfast})
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
var done func(balancer.DoneInfo)
|
|
if p != nil {
|
|
done = func(i balancer.DoneInfo) { p() }
|
|
}
|
|
var sc balancer.SubConn
|
|
bw.mu.Lock()
|
|
defer bw.mu.Unlock()
|
|
if bw.pickfirst {
|
|
// Get the first sc in conns.
|
|
for _, sc = range bw.conns {
|
|
break
|
|
}
|
|
} else {
|
|
var ok bool
|
|
sc, ok = bw.conns[resolver.Address{
|
|
Addr: a.Addr,
|
|
Type: resolver.Backend,
|
|
ServerName: "",
|
|
Metadata: a.Metadata,
|
|
}]
|
|
if !ok && failfast {
|
|
return nil, nil, status.Errorf(codes.Unavailable, "there is no connection available")
|
|
}
|
|
if s, ok := bw.connSt[sc]; failfast && (!ok || s.s != connectivity.Ready) {
|
|
// If the returned sc is not ready and RPC is failfast,
|
|
// return error, and this RPC will fail.
|
|
return nil, nil, status.Errorf(codes.Unavailable, "there is no connection available")
|
|
}
|
|
}
|
|
|
|
return sc, done, nil
|
|
}
|