Fix etcd to use v3.5.0-alpha.0 (#4628)

Signed-off-by: Jason Du <xdu@infoblox.com>

go.mod

@@ -12,7 +12,6 @@ require (
 	github.com/aws/aws-sdk-go v1.38.37
 	github.com/coredns/caddy v1.1.0
 	github.com/dnstap/golang-dnstap v0.4.0
-	github.com/dustin/go-humanize v1.0.0 // indirect
 	github.com/farsightsec/golang-framestream v0.3.0
 	github.com/golang/protobuf v1.5.2
 	github.com/grpc-ecosystem/grpc-opentracing v0.0.0-20180507213350-8e809c8a8645
@@ -28,17 +27,19 @@ require (
 	github.com/prometheus/client_golang v1.10.0
 	github.com/prometheus/client_model v0.2.0
 	github.com/prometheus/common v0.23.0
-	go.etcd.io/etcd v0.5.0-alpha.5.0.20200306183522-221f0cc107cb
+	go.etcd.io/etcd/api/v3 v3.5.0-alpha.0
+	go.etcd.io/etcd/client/v3 v3.5.0-alpha.0
 	go.uber.org/multierr v1.6.0 // indirect
-	go.uber.org/zap v1.16.0 // indirect
 	golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2
 	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 // indirect
 	golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57
 	google.golang.org/api v0.29.0
-	google.golang.org/grpc v1.29.1
+	google.golang.org/grpc v1.37.1
 	gopkg.in/DataDog/dd-trace-go.v1 v1.28.0
 	k8s.io/api v0.21.0
 	k8s.io/apimachinery v0.21.0
 	k8s.io/client-go v0.21.0
 	k8s.io/klog v1.0.0
 )
+
+replace github.com/coreos/bbolt => go.etcd.io/bbolt v1.3.4

plugin/etcd/etcd.go

@@ -16,8 +16,8 @@ import (
 	"github.com/coredns/coredns/request"
 
 	"github.com/miekg/dns"
-	etcdcv3 "go.etcd.io/etcd/clientv3"
-	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.etcd.io/etcd/api/v3/mvccpb"
+	etcdcv3 "go.etcd.io/etcd/client/v3"
 )
 
 const (

plugin/etcd/setup.go

@@ -9,7 +9,7 @@ import (
 	mwtls "github.com/coredns/coredns/plugin/pkg/tls"
 	"github.com/coredns/coredns/plugin/pkg/upstream"
 
-	etcdcv3 "go.etcd.io/etcd/clientv3"
+	etcdcv3 "go.etcd.io/etcd/client/v3"
 )
 
 func init() { plugin.Register("etcd", setup) }

test/etcd_test.go

@@ -12,7 +12,7 @@ import (
 	"github.com/coredns/coredns/plugin/etcd/msg"
 
 	"github.com/miekg/dns"
-	etcdcv3 "go.etcd.io/etcd/clientv3"
+	etcdcv3 "go.etcd.io/etcd/client/v3"
 )
 
 func etcdPlugin() *etcd.Etcd {