[VOL-4291] OfAgent changes for gRPC migration
Change-Id: I8da1db6df49d478ef24ec8f9bd719e9692f48a7f
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/balancer.go b/vendor/github.com/coreos/etcd/clientv3/balancer/balancer.go
new file mode 100644
index 0000000..9306385
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/balancer.go
@@ -0,0 +1,293 @@
+// Copyright 2018 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 balancer implements client balancer.
+package balancer
+
+import (
+ "strconv"
+ "sync"
+ "time"
+
+ "github.com/coreos/etcd/clientv3/balancer/connectivity"
+ "github.com/coreos/etcd/clientv3/balancer/picker"
+
+ "go.uber.org/zap"
+ "google.golang.org/grpc/balancer"
+ grpcconnectivity "google.golang.org/grpc/connectivity"
+ "google.golang.org/grpc/resolver"
+ _ "google.golang.org/grpc/resolver/dns" // register DNS resolver
+ _ "google.golang.org/grpc/resolver/passthrough" // register passthrough resolver
+)
+
+// Config defines balancer configurations.
+type Config struct {
+ // Policy configures balancer policy.
+ Policy picker.Policy
+
+ // Picker implements gRPC picker.
+ // Leave empty if "Policy" field is not custom.
+ // TODO: currently custom policy is not supported.
+ // Picker picker.Picker
+
+ // Name defines an additional name for balancer.
+ // Useful for balancer testing to avoid register conflicts.
+ // If empty, defaults to policy name.
+ Name string
+
+ // Logger configures balancer logging.
+ // If nil, logs are discarded.
+ Logger *zap.Logger
+}
+
+// RegisterBuilder creates and registers a builder. Since this function calls balancer.Register, it
+// must be invoked at initialization time.
+func RegisterBuilder(cfg Config) {
+ bb := &builder{cfg}
+ balancer.Register(bb)
+
+ bb.cfg.Logger.Debug(
+ "registered balancer",
+ zap.String("policy", bb.cfg.Policy.String()),
+ zap.String("name", bb.cfg.Name),
+ )
+}
+
+type builder struct {
+ cfg Config
+}
+
+// Build is called initially when creating "ccBalancerWrapper".
+// "grpc.Dial" is called to this client connection.
+// Then, resolved addresses will be handled via "HandleResolvedAddrs".
+func (b *builder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) balancer.Balancer {
+ bb := &baseBalancer{
+ id: strconv.FormatInt(time.Now().UnixNano(), 36),
+ policy: b.cfg.Policy,
+ name: b.cfg.Name,
+ lg: b.cfg.Logger,
+
+ addrToSc: make(map[resolver.Address]balancer.SubConn),
+ scToAddr: make(map[balancer.SubConn]resolver.Address),
+ scToSt: make(map[balancer.SubConn]grpcconnectivity.State),
+
+ currentConn: nil,
+ connectivityRecorder: connectivity.New(b.cfg.Logger),
+
+ // initialize picker always returns "ErrNoSubConnAvailable"
+ picker: picker.NewErr(balancer.ErrNoSubConnAvailable),
+ }
+
+ // TODO: support multiple connections
+ bb.mu.Lock()
+ bb.currentConn = cc
+ bb.mu.Unlock()
+
+ bb.lg.Info(
+ "built balancer",
+ zap.String("balancer-id", bb.id),
+ zap.String("policy", bb.policy.String()),
+ zap.String("resolver-target", cc.Target()),
+ )
+ return bb
+}
+
+// Name implements "grpc/balancer.Builder" interface.
+func (b *builder) Name() string { return b.cfg.Name }
+
+// Balancer defines client balancer interface.
+type Balancer interface {
+ // Balancer is called on specified client connection. Client initiates gRPC
+ // connection with "grpc.Dial(addr, grpc.WithBalancerName)", and then those resolved
+ // addresses are passed to "grpc/balancer.Balancer.HandleResolvedAddrs".
+ // For each resolved address, balancer calls "balancer.ClientConn.NewSubConn".
+ // "grpc/balancer.Balancer.HandleSubConnStateChange" is called when connectivity state
+ // changes, thus requires failover logic in this method.
+ balancer.Balancer
+
+ // Picker calls "Pick" for every client request.
+ picker.Picker
+}
+
+type baseBalancer struct {
+ id string
+ policy picker.Policy
+ name string
+ lg *zap.Logger
+
+ mu sync.RWMutex
+
+ addrToSc map[resolver.Address]balancer.SubConn
+ scToAddr map[balancer.SubConn]resolver.Address
+ scToSt map[balancer.SubConn]grpcconnectivity.State
+
+ currentConn balancer.ClientConn
+ connectivityRecorder connectivity.Recorder
+
+ picker picker.Picker
+}
+
+// HandleResolvedAddrs implements "grpc/balancer.Balancer" interface.
+// gRPC sends initial or updated resolved addresses from "Build".
+func (bb *baseBalancer) HandleResolvedAddrs(addrs []resolver.Address, err error) {
+ if err != nil {
+ bb.lg.Warn("HandleResolvedAddrs called with error", zap.String("balancer-id", bb.id), zap.Error(err))
+ return
+ }
+ bb.lg.Info("resolved",
+ zap.String("picker", bb.picker.String()),
+ zap.String("balancer-id", bb.id),
+ zap.Strings("addresses", addrsToStrings(addrs)),
+ )
+
+ bb.mu.Lock()
+ defer bb.mu.Unlock()
+
+ resolved := make(map[resolver.Address]struct{})
+ for _, addr := range addrs {
+ resolved[addr] = struct{}{}
+ if _, ok := bb.addrToSc[addr]; !ok {
+ sc, err := bb.currentConn.NewSubConn([]resolver.Address{addr}, balancer.NewSubConnOptions{})
+ if err != nil {
+ bb.lg.Warn("NewSubConn failed", zap.String("picker", bb.picker.String()), zap.String("balancer-id", bb.id), zap.Error(err), zap.String("address", addr.Addr))
+ continue
+ }
+ bb.lg.Info("created subconn", zap.String("address", addr.Addr))
+ bb.addrToSc[addr] = sc
+ bb.scToAddr[sc] = addr
+ bb.scToSt[sc] = grpcconnectivity.Idle
+ sc.Connect()
+ }
+ }
+
+ for addr, sc := range bb.addrToSc {
+ if _, ok := resolved[addr]; !ok {
+ // was removed by resolver or failed to create subconn
+ bb.currentConn.RemoveSubConn(sc)
+ delete(bb.addrToSc, addr)
+
+ bb.lg.Info(
+ "removed subconn",
+ zap.String("picker", bb.picker.String()),
+ zap.String("balancer-id", bb.id),
+ zap.String("address", addr.Addr),
+ zap.String("subconn", scToString(sc)),
+ )
+
+ // Keep the state of this sc in bb.scToSt until sc's state becomes Shutdown.
+ // The entry will be deleted in HandleSubConnStateChange.
+ // (DO NOT) delete(bb.scToAddr, sc)
+ // (DO NOT) delete(bb.scToSt, sc)
+ }
+ }
+}
+
+// HandleSubConnStateChange implements "grpc/balancer.Balancer" interface.
+func (bb *baseBalancer) HandleSubConnStateChange(sc balancer.SubConn, s grpcconnectivity.State) {
+ bb.mu.Lock()
+ defer bb.mu.Unlock()
+
+ old, ok := bb.scToSt[sc]
+ if !ok {
+ bb.lg.Warn(
+ "state change for an unknown subconn",
+ zap.String("picker", bb.picker.String()),
+ zap.String("balancer-id", bb.id),
+ zap.String("subconn", scToString(sc)),
+ zap.Int("subconn-size", len(bb.scToAddr)),
+ zap.String("state", s.String()),
+ )
+ return
+ }
+
+ bb.lg.Info(
+ "state changed",
+ zap.String("picker", bb.picker.String()),
+ zap.String("balancer-id", bb.id),
+ zap.Bool("connected", s == grpcconnectivity.Ready),
+ zap.String("subconn", scToString(sc)),
+ zap.Int("subconn-size", len(bb.scToAddr)),
+ zap.String("address", bb.scToAddr[sc].Addr),
+ zap.String("old-state", old.String()),
+ zap.String("new-state", s.String()),
+ )
+
+ bb.scToSt[sc] = s
+ switch s {
+ case grpcconnectivity.Idle:
+ sc.Connect()
+ case grpcconnectivity.Shutdown:
+ // When an address was removed by resolver, b called RemoveSubConn but
+ // kept the sc's state in scToSt. Remove state for this sc here.
+ delete(bb.scToAddr, sc)
+ delete(bb.scToSt, sc)
+ }
+
+ oldAggrState := bb.connectivityRecorder.GetCurrentState()
+ bb.connectivityRecorder.RecordTransition(old, s)
+
+ // Update balancer picker when one of the following happens:
+ // - this sc became ready from not-ready
+ // - this sc became not-ready from ready
+ // - the aggregated state of balancer became TransientFailure from non-TransientFailure
+ // - the aggregated state of balancer became non-TransientFailure from TransientFailure
+ if (s == grpcconnectivity.Ready) != (old == grpcconnectivity.Ready) ||
+ (bb.connectivityRecorder.GetCurrentState() == grpcconnectivity.TransientFailure) != (oldAggrState == grpcconnectivity.TransientFailure) {
+ bb.updatePicker()
+ }
+
+ bb.currentConn.UpdateBalancerState(bb.connectivityRecorder.GetCurrentState(), bb.picker)
+}
+
+func (bb *baseBalancer) updatePicker() {
+ if bb.connectivityRecorder.GetCurrentState() == grpcconnectivity.TransientFailure {
+ bb.picker = picker.NewErr(balancer.ErrTransientFailure)
+ bb.lg.Info(
+ "updated picker to transient error picker",
+ zap.String("picker", bb.picker.String()),
+ zap.String("balancer-id", bb.id),
+ zap.String("policy", bb.policy.String()),
+ )
+ return
+ }
+
+ // only pass ready subconns to picker
+ scToAddr := make(map[balancer.SubConn]resolver.Address)
+ for addr, sc := range bb.addrToSc {
+ if st, ok := bb.scToSt[sc]; ok && st == grpcconnectivity.Ready {
+ scToAddr[sc] = addr
+ }
+ }
+
+ bb.picker = picker.New(picker.Config{
+ Policy: bb.policy,
+ Logger: bb.lg,
+ SubConnToResolverAddress: scToAddr,
+ })
+ bb.lg.Info(
+ "updated picker",
+ zap.String("picker", bb.picker.String()),
+ zap.String("balancer-id", bb.id),
+ zap.String("policy", bb.policy.String()),
+ zap.Strings("subconn-ready", scsToStrings(scToAddr)),
+ zap.Int("subconn-size", len(scToAddr)),
+ )
+}
+
+// Close implements "grpc/balancer.Balancer" interface.
+// Close is a nop because base balancer doesn't have internal state to clean up,
+// and it doesn't need to call RemoveSubConn for the SubConns.
+func (bb *baseBalancer) Close() {
+ // TODO
+}
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/connectivity/connectivity.go b/vendor/github.com/coreos/etcd/clientv3/balancer/connectivity/connectivity.go
new file mode 100644
index 0000000..4c4ad36
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/connectivity/connectivity.go
@@ -0,0 +1,93 @@
+// Copyright 2019 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 connectivity implements client connectivity operations.
+package connectivity
+
+import (
+ "sync"
+
+ "go.uber.org/zap"
+ "google.golang.org/grpc/connectivity"
+)
+
+// Recorder records gRPC connectivity.
+type Recorder interface {
+ GetCurrentState() connectivity.State
+ RecordTransition(oldState, newState connectivity.State)
+}
+
+// New returns a new Recorder.
+func New(lg *zap.Logger) Recorder {
+ return &recorder{lg: lg}
+}
+
+// recorder takes the connectivity states of multiple SubConns
+// and returns one aggregated connectivity state.
+// ref. https://github.com/grpc/grpc-go/blob/master/balancer/balancer.go
+type recorder struct {
+ lg *zap.Logger
+
+ mu sync.RWMutex
+
+ cur connectivity.State
+
+ numReady uint64 // Number of addrConns in ready state.
+ numConnecting uint64 // Number of addrConns in connecting state.
+ numTransientFailure uint64 // Number of addrConns in transientFailure.
+}
+
+func (rc *recorder) GetCurrentState() (state connectivity.State) {
+ rc.mu.RLock()
+ defer rc.mu.RUnlock()
+ return rc.cur
+}
+
+// RecordTransition records state change happening in subConn and based on that
+// it evaluates what aggregated state should be.
+//
+// - If at least one SubConn in Ready, the aggregated state is Ready;
+// - Else if at least one SubConn in Connecting, the aggregated state is Connecting;
+// - Else the aggregated state is TransientFailure.
+//
+// Idle and Shutdown are not considered.
+//
+// ref. https://github.com/grpc/grpc-go/blob/master/balancer/balancer.go
+func (rc *recorder) RecordTransition(oldState, newState connectivity.State) {
+ rc.mu.Lock()
+ defer rc.mu.Unlock()
+
+ for idx, state := range []connectivity.State{oldState, newState} {
+ updateVal := 2*uint64(idx) - 1 // -1 for oldState and +1 for new.
+ switch state {
+ case connectivity.Ready:
+ rc.numReady += updateVal
+ case connectivity.Connecting:
+ rc.numConnecting += updateVal
+ case connectivity.TransientFailure:
+ rc.numTransientFailure += updateVal
+ default:
+ rc.lg.Warn("connectivity recorder received unknown state", zap.String("connectivity-state", state.String()))
+ }
+ }
+
+ switch { // must be exclusive, no overlap
+ case rc.numReady > 0:
+ rc.cur = connectivity.Ready
+ case rc.numConnecting > 0:
+ rc.cur = connectivity.Connecting
+ default:
+ rc.cur = connectivity.TransientFailure
+ }
+}
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/picker/doc.go b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/doc.go
new file mode 100644
index 0000000..35dabf5
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2018 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 picker defines/implements client balancer picker policy.
+package picker
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/picker/err.go b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/err.go
new file mode 100644
index 0000000..9e04378
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/err.go
@@ -0,0 +1,39 @@
+// Copyright 2018 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 picker
+
+import (
+ "context"
+
+ "google.golang.org/grpc/balancer"
+)
+
+// NewErr returns a picker that always returns err on "Pick".
+func NewErr(err error) Picker {
+ return &errPicker{p: Error, err: err}
+}
+
+type errPicker struct {
+ p Policy
+ err error
+}
+
+func (ep *errPicker) String() string {
+ return ep.p.String()
+}
+
+func (ep *errPicker) Pick(context.Context, balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
+ return nil, nil, ep.err
+}
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/picker/picker.go b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/picker.go
new file mode 100644
index 0000000..bd1a5d2
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/picker.go
@@ -0,0 +1,91 @@
+// Copyright 2018 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 picker
+
+import (
+ "fmt"
+
+ "go.uber.org/zap"
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/resolver"
+)
+
+// Picker defines balancer Picker methods.
+type Picker interface {
+ balancer.Picker
+ String() string
+}
+
+// Config defines picker configuration.
+type Config struct {
+ // Policy specifies etcd clientv3's built in balancer policy.
+ Policy Policy
+
+ // Logger defines picker logging object.
+ Logger *zap.Logger
+
+ // SubConnToResolverAddress maps each gRPC sub-connection to an address.
+ // Basically, it is a list of addresses that the Picker can pick from.
+ SubConnToResolverAddress map[balancer.SubConn]resolver.Address
+}
+
+// Policy defines balancer picker policy.
+type Policy uint8
+
+const (
+ // Error is error picker policy.
+ Error Policy = iota
+
+ // RoundrobinBalanced balances loads over multiple endpoints
+ // and implements failover in roundrobin fashion.
+ RoundrobinBalanced
+
+ // Custom defines custom balancer picker.
+ // TODO: custom picker is not supported yet.
+ Custom
+)
+
+func (p Policy) String() string {
+ switch p {
+ case Error:
+ return "picker-error"
+
+ case RoundrobinBalanced:
+ return "picker-roundrobin-balanced"
+
+ case Custom:
+ panic("'custom' picker policy is not supported yet")
+
+ default:
+ panic(fmt.Errorf("invalid balancer picker policy (%d)", p))
+ }
+}
+
+// New creates a new Picker.
+func New(cfg Config) Picker {
+ switch cfg.Policy {
+ case Error:
+ panic("'error' picker policy is not supported here; use 'picker.NewErr'")
+
+ case RoundrobinBalanced:
+ return newRoundrobinBalanced(cfg)
+
+ case Custom:
+ panic("'custom' picker policy is not supported yet")
+
+ default:
+ panic(fmt.Errorf("invalid balancer picker policy (%d)", cfg.Policy))
+ }
+}
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/picker/roundrobin_balanced.go b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/roundrobin_balanced.go
new file mode 100644
index 0000000..1b8b285
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/picker/roundrobin_balanced.go
@@ -0,0 +1,95 @@
+// Copyright 2018 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 picker
+
+import (
+ "context"
+ "sync"
+
+ "go.uber.org/zap"
+ "go.uber.org/zap/zapcore"
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/resolver"
+)
+
+// newRoundrobinBalanced returns a new roundrobin balanced picker.
+func newRoundrobinBalanced(cfg Config) Picker {
+ scs := make([]balancer.SubConn, 0, len(cfg.SubConnToResolverAddress))
+ for sc := range cfg.SubConnToResolverAddress {
+ scs = append(scs, sc)
+ }
+ return &rrBalanced{
+ p: RoundrobinBalanced,
+ lg: cfg.Logger,
+ scs: scs,
+ scToAddr: cfg.SubConnToResolverAddress,
+ }
+}
+
+type rrBalanced struct {
+ p Policy
+
+ lg *zap.Logger
+
+ mu sync.RWMutex
+ next int
+ scs []balancer.SubConn
+ scToAddr map[balancer.SubConn]resolver.Address
+}
+
+func (rb *rrBalanced) String() string { return rb.p.String() }
+
+// Pick is called for every client request.
+func (rb *rrBalanced) Pick(ctx context.Context, opts balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
+ rb.mu.RLock()
+ n := len(rb.scs)
+ rb.mu.RUnlock()
+ if n == 0 {
+ return nil, nil, balancer.ErrNoSubConnAvailable
+ }
+
+ rb.mu.Lock()
+ cur := rb.next
+ sc := rb.scs[cur]
+ picked := rb.scToAddr[sc].Addr
+ rb.next = (rb.next + 1) % len(rb.scs)
+ rb.mu.Unlock()
+
+ rb.lg.Debug(
+ "picked",
+ zap.String("picker", rb.p.String()),
+ zap.String("address", picked),
+ zap.Int("subconn-index", cur),
+ zap.Int("subconn-size", n),
+ )
+
+ doneFunc := func(info balancer.DoneInfo) {
+ // TODO: error handling?
+ fss := []zapcore.Field{
+ zap.Error(info.Err),
+ zap.String("picker", rb.p.String()),
+ zap.String("address", picked),
+ zap.Bool("success", info.Err == nil),
+ zap.Bool("bytes-sent", info.BytesSent),
+ zap.Bool("bytes-received", info.BytesReceived),
+ }
+ if info.Err == nil {
+ rb.lg.Debug("balancer done", fss...)
+ } else {
+ rb.lg.Warn("balancer failed", fss...)
+ }
+ }
+ return sc, doneFunc, nil
+}
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/resolver/endpoint/endpoint.go b/vendor/github.com/coreos/etcd/clientv3/balancer/resolver/endpoint/endpoint.go
new file mode 100644
index 0000000..864b5df
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/resolver/endpoint/endpoint.go
@@ -0,0 +1,247 @@
+// Copyright 2018 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 endpoint resolves etcd entpoints using grpc targets of the form 'endpoint://<id>/<endpoint>'.
+package endpoint
+
+import (
+ "context"
+ "fmt"
+ "net"
+ "net/url"
+ "strings"
+ "sync"
+
+ "google.golang.org/grpc/resolver"
+)
+
+const scheme = "endpoint"
+
+var (
+ targetPrefix = fmt.Sprintf("%s://", scheme)
+
+ bldr *builder
+)
+
+func init() {
+ bldr = &builder{
+ resolverGroups: make(map[string]*ResolverGroup),
+ }
+ resolver.Register(bldr)
+}
+
+type builder struct {
+ mu sync.RWMutex
+ resolverGroups map[string]*ResolverGroup
+}
+
+// NewResolverGroup creates a new ResolverGroup with the given id.
+func NewResolverGroup(id string) (*ResolverGroup, error) {
+ return bldr.newResolverGroup(id)
+}
+
+// ResolverGroup keeps all endpoints of resolvers using a common endpoint://<id>/ target
+// up-to-date.
+type ResolverGroup struct {
+ mu sync.RWMutex
+ id string
+ endpoints []string
+ resolvers []*Resolver
+}
+
+func (e *ResolverGroup) addResolver(r *Resolver) {
+ e.mu.Lock()
+ addrs := epsToAddrs(e.endpoints...)
+ e.resolvers = append(e.resolvers, r)
+ e.mu.Unlock()
+ r.cc.NewAddress(addrs)
+}
+
+func (e *ResolverGroup) removeResolver(r *Resolver) {
+ e.mu.Lock()
+ for i, er := range e.resolvers {
+ if er == r {
+ e.resolvers = append(e.resolvers[:i], e.resolvers[i+1:]...)
+ break
+ }
+ }
+ e.mu.Unlock()
+}
+
+// SetEndpoints updates the endpoints for ResolverGroup. All registered resolver are updated
+// immediately with the new endpoints.
+func (e *ResolverGroup) SetEndpoints(endpoints []string) {
+ addrs := epsToAddrs(endpoints...)
+ e.mu.Lock()
+ e.endpoints = endpoints
+ for _, r := range e.resolvers {
+ r.cc.NewAddress(addrs)
+ }
+ e.mu.Unlock()
+}
+
+// Target constructs a endpoint target using the endpoint id of the ResolverGroup.
+func (e *ResolverGroup) Target(endpoint string) string {
+ return Target(e.id, endpoint)
+}
+
+// Target constructs a endpoint resolver target.
+func Target(id, endpoint string) string {
+ return fmt.Sprintf("%s://%s/%s", scheme, id, endpoint)
+}
+
+// IsTarget checks if a given target string in an endpoint resolver target.
+func IsTarget(target string) bool {
+ return strings.HasPrefix(target, "endpoint://")
+}
+
+func (e *ResolverGroup) Close() {
+ bldr.close(e.id)
+}
+
+// Build creates or reuses an etcd resolver for the etcd cluster name identified by the authority part of the target.
+func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOption) (resolver.Resolver, error) {
+ if len(target.Authority) < 1 {
+ return nil, fmt.Errorf("'etcd' target scheme requires non-empty authority identifying etcd cluster being routed to")
+ }
+ id := target.Authority
+ es, err := b.getResolverGroup(id)
+ if err != nil {
+ return nil, fmt.Errorf("failed to build resolver: %v", err)
+ }
+ r := &Resolver{
+ endpointID: id,
+ cc: cc,
+ }
+ es.addResolver(r)
+ return r, nil
+}
+
+func (b *builder) newResolverGroup(id string) (*ResolverGroup, error) {
+ b.mu.RLock()
+ _, ok := b.resolverGroups[id]
+ b.mu.RUnlock()
+ if ok {
+ return nil, fmt.Errorf("Endpoint already exists for id: %s", id)
+ }
+
+ es := &ResolverGroup{id: id}
+ b.mu.Lock()
+ b.resolverGroups[id] = es
+ b.mu.Unlock()
+ return es, nil
+}
+
+func (b *builder) getResolverGroup(id string) (*ResolverGroup, error) {
+ b.mu.RLock()
+ es, ok := b.resolverGroups[id]
+ b.mu.RUnlock()
+ if !ok {
+ return nil, fmt.Errorf("ResolverGroup not found for id: %s", id)
+ }
+ return es, nil
+}
+
+func (b *builder) close(id string) {
+ b.mu.Lock()
+ delete(b.resolverGroups, id)
+ b.mu.Unlock()
+}
+
+func (b *builder) Scheme() string {
+ return scheme
+}
+
+// Resolver provides a resolver for a single etcd cluster, identified by name.
+type Resolver struct {
+ endpointID string
+ cc resolver.ClientConn
+ sync.RWMutex
+}
+
+// TODO: use balancer.epsToAddrs
+func epsToAddrs(eps ...string) (addrs []resolver.Address) {
+ addrs = make([]resolver.Address, 0, len(eps))
+ for _, ep := range eps {
+ addrs = append(addrs, resolver.Address{Addr: ep})
+ }
+ return addrs
+}
+
+func (*Resolver) ResolveNow(o resolver.ResolveNowOption) {}
+
+func (r *Resolver) Close() {
+ es, err := bldr.getResolverGroup(r.endpointID)
+ if err != nil {
+ return
+ }
+ es.removeResolver(r)
+}
+
+// ParseEndpoint endpoint parses an endpoint of the form
+// (http|https)://<host>*|(unix|unixs)://<path>)
+// and returns a protocol ('tcp' or 'unix'),
+// host (or filepath if a unix socket),
+// scheme (http, https, unix, unixs).
+func ParseEndpoint(endpoint string) (proto string, host string, scheme string) {
+ proto = "tcp"
+ host = endpoint
+ url, uerr := url.Parse(endpoint)
+ if uerr != nil || !strings.Contains(endpoint, "://") {
+ return proto, host, scheme
+ }
+ scheme = url.Scheme
+
+ // strip scheme:// prefix since grpc dials by host
+ host = url.Host
+ switch url.Scheme {
+ case "http", "https":
+ case "unix", "unixs":
+ proto = "unix"
+ host = url.Host + url.Path
+ default:
+ proto, host = "", ""
+ }
+ return proto, host, scheme
+}
+
+// ParseTarget parses a endpoint://<id>/<endpoint> string and returns the parsed id and endpoint.
+// If the target is malformed, an error is returned.
+func ParseTarget(target string) (string, string, error) {
+ noPrefix := strings.TrimPrefix(target, targetPrefix)
+ if noPrefix == target {
+ return "", "", fmt.Errorf("malformed target, %s prefix is required: %s", targetPrefix, target)
+ }
+ parts := strings.SplitN(noPrefix, "/", 2)
+ if len(parts) != 2 {
+ return "", "", fmt.Errorf("malformed target, expected %s://<id>/<endpoint>, but got %s", scheme, target)
+ }
+ return parts[0], parts[1], nil
+}
+
+// Dialer dials a endpoint using net.Dialer.
+// Context cancelation and timeout are supported.
+func Dialer(ctx context.Context, dialEp string) (net.Conn, error) {
+ proto, host, _ := ParseEndpoint(dialEp)
+ select {
+ case <-ctx.Done():
+ return nil, ctx.Err()
+ default:
+ }
+ dialer := &net.Dialer{}
+ if deadline, ok := ctx.Deadline(); ok {
+ dialer.Deadline = deadline
+ }
+ return dialer.DialContext(ctx, proto, host)
+}
diff --git a/vendor/github.com/coreos/etcd/clientv3/balancer/utils.go b/vendor/github.com/coreos/etcd/clientv3/balancer/utils.go
new file mode 100644
index 0000000..48eb875
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/clientv3/balancer/utils.go
@@ -0,0 +1,68 @@
+// Copyright 2018 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 balancer
+
+import (
+ "fmt"
+ "net/url"
+ "sort"
+ "sync/atomic"
+ "time"
+
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/resolver"
+)
+
+func scToString(sc balancer.SubConn) string {
+ return fmt.Sprintf("%p", sc)
+}
+
+func scsToStrings(scs map[balancer.SubConn]resolver.Address) (ss []string) {
+ ss = make([]string, 0, len(scs))
+ for sc, a := range scs {
+ ss = append(ss, fmt.Sprintf("%s (%s)", a.Addr, scToString(sc)))
+ }
+ sort.Strings(ss)
+ return ss
+}
+
+func addrsToStrings(addrs []resolver.Address) (ss []string) {
+ ss = make([]string, len(addrs))
+ for i := range addrs {
+ ss[i] = addrs[i].Addr
+ }
+ sort.Strings(ss)
+ return ss
+}
+
+func epsToAddrs(eps ...string) (addrs []resolver.Address) {
+ addrs = make([]resolver.Address, 0, len(eps))
+ for _, ep := range eps {
+ u, err := url.Parse(ep)
+ if err != nil {
+ addrs = append(addrs, resolver.Address{Addr: ep, Type: resolver.Backend})
+ continue
+ }
+ addrs = append(addrs, resolver.Address{Addr: u.Host, Type: resolver.Backend})
+ }
+ return addrs
+}
+
+var genN = new(uint32)
+
+func genName() string {
+ now := time.Now().UnixNano()
+ return fmt.Sprintf("%X%X", now, atomic.AddUint32(genN, 1))
+}