VOL-1921 - updated to use go mod

Change-Id: I8d5187fa91fa619494f972bc29d3bd61e5be3a82
diff --git a/vendor/go.etcd.io/etcd/clientv3/balancer/picker/err.go b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/err.go
index c70ce15..9e04378 100644
--- a/vendor/go.etcd.io/etcd/clientv3/balancer/picker/err.go
+++ b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/err.go
@@ -22,13 +22,18 @@
 
 // NewErr returns a picker that always returns err on "Pick".
 func NewErr(err error) Picker {
-	return &errPicker{err: err}
+	return &errPicker{p: Error, err: err}
 }
 
 type errPicker struct {
+	p   Policy
 	err error
 }
 
-func (p *errPicker) Pick(context.Context, balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
-	return nil, nil, p.err
+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/go.etcd.io/etcd/clientv3/balancer/picker/picker.go b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker.go
index 7ea761b..bd1a5d2 100644
--- a/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker.go
+++ b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker.go
@@ -15,10 +15,77 @@
 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/go.etcd.io/etcd/clientv3/balancer/picker/picker_policy.go b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker_policy.go
deleted file mode 100644
index 7bca39c..0000000
--- a/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker_policy.go
+++ /dev/null
@@ -1,49 +0,0 @@
-// 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"
-
-// Policy defines balancer picker policy.
-type Policy uint8
-
-const (
-	// TODO: custom picker is not supported yet.
-	// custom defines custom balancer picker.
-	custom Policy = iota
-
-	// RoundrobinBalanced balance loads over multiple endpoints
-	// and implements failover in roundrobin fashion.
-	RoundrobinBalanced Policy = iota
-
-	// TODO: only send loads to pinned address "RoundrobinFailover"
-	// just like how 3.3 client works
-	//
-	// TODO: prioritize leader
-	// TODO: health-check
-	// TODO: weighted roundrobin
-	// TODO: power of two random choice
-)
-
-func (p Policy) String() string {
-	switch p {
-	case custom:
-		panic("'custom' picker policy is not supported yet")
-	case RoundrobinBalanced:
-		return "etcd-client-roundrobin-balanced"
-	default:
-		panic(fmt.Errorf("invalid balancer picker policy (%d)", p))
-	}
-}
diff --git a/vendor/go.etcd.io/etcd/clientv3/balancer/picker/roundrobin_balanced.go b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/roundrobin_balanced.go
index b043d57..1b8b285 100644
--- a/vendor/go.etcd.io/etcd/clientv3/balancer/picker/roundrobin_balanced.go
+++ b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/roundrobin_balanced.go
@@ -24,32 +24,33 @@
 	"google.golang.org/grpc/resolver"
 )
 
-// NewRoundrobinBalanced returns a new roundrobin balanced picker.
-func NewRoundrobinBalanced(
-	lg *zap.Logger,
-	scs []balancer.SubConn,
-	addrToSc map[resolver.Address]balancer.SubConn,
-	scToAddr map[balancer.SubConn]resolver.Address,
-) Picker {
+// 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{
-		lg:       lg,
+		p:        RoundrobinBalanced,
+		lg:       cfg.Logger,
 		scs:      scs,
-		addrToSc: addrToSc,
-		scToAddr: scToAddr,
+		scToAddr: cfg.SubConnToResolverAddress,
 	}
 }
 
 type rrBalanced struct {
+	p Policy
+
 	lg *zap.Logger
 
-	mu   sync.RWMutex
-	next int
-	scs  []balancer.SubConn
-
-	addrToSc map[resolver.Address]balancer.SubConn
+	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()
@@ -68,6 +69,7 @@
 
 	rb.lg.Debug(
 		"picked",
+		zap.String("picker", rb.p.String()),
 		zap.String("address", picked),
 		zap.Int("subconn-index", cur),
 		zap.Int("subconn-size", n),
@@ -77,6 +79,7 @@
 		// 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),