[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/lease/metrics.go b/vendor/go.etcd.io/etcd/lease/metrics.go
new file mode 100644
index 0000000..06f8b58
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/metrics.go
@@ -0,0 +1,59 @@
+// 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 lease
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	leaseGranted = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "lease",
+		Name:      "granted_total",
+		Help:      "The total number of granted leases.",
+	})
+
+	leaseRevoked = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "lease",
+		Name:      "revoked_total",
+		Help:      "The total number of revoked leases.",
+	})
+
+	leaseRenewed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "lease",
+		Name:      "renewed_total",
+		Help:      "The number of renewed leases seen by the leader.",
+	})
+
+	leaseTotalTTLs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "lease",
+			Name:      "ttl_total",
+			Help:      "Bucketed histogram of lease TTLs.",
+			// 1 second -> 3 months
+			Buckets: prometheus.ExponentialBuckets(1, 2, 24),
+		})
+)
+
+func init() {
+	prometheus.MustRegister(leaseGranted)
+	prometheus.MustRegister(leaseRevoked)
+	prometheus.MustRegister(leaseRenewed)
+	prometheus.MustRegister(leaseTotalTTLs)
+}