[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/lease.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/lease.go
new file mode 100644
index 0000000..7441bee
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/lease.go
@@ -0,0 +1,169 @@
+// 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 v3rpc
+
+import (
+	"context"
+	"io"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+
+	"go.uber.org/zap"
+)
+
+type LeaseServer struct {
+	lg  *zap.Logger
+	hdr header
+	le  etcdserver.Lessor
+}
+
+func NewLeaseServer(s *etcdserver.EtcdServer) pb.LeaseServer {
+	return &LeaseServer{lg: s.Cfg.Logger, le: s, hdr: newHeader(s)}
+}
+
+func (ls *LeaseServer) LeaseGrant(ctx context.Context, cr *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	resp, err := ls.le.LeaseGrant(ctx, cr)
+
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseRevoke(ctx context.Context, rr *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error) {
+	resp, err := ls.le.LeaseRevoke(ctx, rr)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseTimeToLive(ctx context.Context, rr *pb.LeaseTimeToLiveRequest) (*pb.LeaseTimeToLiveResponse, error) {
+	resp, err := ls.le.LeaseTimeToLive(ctx, rr)
+	if err != nil && err != lease.ErrLeaseNotFound {
+		return nil, togRPCError(err)
+	}
+	if err == lease.ErrLeaseNotFound {
+		resp = &pb.LeaseTimeToLiveResponse{
+			Header: &pb.ResponseHeader{},
+			ID:     rr.ID,
+			TTL:    -1,
+		}
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseLeases(ctx context.Context, rr *pb.LeaseLeasesRequest) (*pb.LeaseLeasesResponse, error) {
+	resp, err := ls.le.LeaseLeases(ctx, rr)
+	if err != nil && err != lease.ErrLeaseNotFound {
+		return nil, togRPCError(err)
+	}
+	if err == lease.ErrLeaseNotFound {
+		resp = &pb.LeaseLeasesResponse{
+			Header: &pb.ResponseHeader{},
+			Leases: []*pb.LeaseStatus{},
+		}
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseKeepAlive(stream pb.Lease_LeaseKeepAliveServer) (err error) {
+	errc := make(chan error, 1)
+	go func() {
+		errc <- ls.leaseKeepAlive(stream)
+	}()
+	select {
+	case err = <-errc:
+	case <-stream.Context().Done():
+		// the only server-side cancellation is noleader for now.
+		err = stream.Context().Err()
+		if err == context.Canceled {
+			err = rpctypes.ErrGRPCNoLeader
+		}
+	}
+	return err
+}
+
+func (ls *LeaseServer) leaseKeepAlive(stream pb.Lease_LeaseKeepAliveServer) error {
+	for {
+		req, err := stream.Recv()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			if isClientCtxErr(stream.Context().Err(), err) {
+				if ls.lg != nil {
+					ls.lg.Debug("failed to receive lease keepalive request from gRPC stream", zap.Error(err))
+				} else {
+					plog.Debugf("failed to receive lease keepalive request from gRPC stream (%q)", err.Error())
+				}
+			} else {
+				if ls.lg != nil {
+					ls.lg.Warn("failed to receive lease keepalive request from gRPC stream", zap.Error(err))
+				} else {
+					plog.Warningf("failed to receive lease keepalive request from gRPC stream (%q)", err.Error())
+				}
+				streamFailures.WithLabelValues("receive", "lease-keepalive").Inc()
+			}
+			return err
+		}
+
+		// Create header before we sent out the renew request.
+		// This can make sure that the revision is strictly smaller or equal to
+		// when the keepalive happened at the local server (when the local server is the leader)
+		// or remote leader.
+		// Without this, a lease might be revoked at rev 3 but client can see the keepalive succeeded
+		// at rev 4.
+		resp := &pb.LeaseKeepAliveResponse{ID: req.ID, Header: &pb.ResponseHeader{}}
+		ls.hdr.fill(resp.Header)
+
+		ttl, err := ls.le.LeaseRenew(stream.Context(), lease.LeaseID(req.ID))
+		if err == lease.ErrLeaseNotFound {
+			err = nil
+			ttl = 0
+		}
+
+		if err != nil {
+			return togRPCError(err)
+		}
+
+		resp.TTL = ttl
+		err = stream.Send(resp)
+		if err != nil {
+			if isClientCtxErr(stream.Context().Err(), err) {
+				if ls.lg != nil {
+					ls.lg.Debug("failed to send lease keepalive response to gRPC stream", zap.Error(err))
+				} else {
+					plog.Debugf("failed to send lease keepalive response to gRPC stream (%q)", err.Error())
+				}
+			} else {
+				if ls.lg != nil {
+					ls.lg.Warn("failed to send lease keepalive response to gRPC stream", zap.Error(err))
+				} else {
+					plog.Warningf("failed to send lease keepalive response to gRPC stream (%q)", err.Error())
+				}
+				streamFailures.WithLabelValues("send", "lease-keepalive").Inc()
+			}
+			return err
+		}
+	}
+}