Etcd Integration test

Signed-off-by: Sriram Natarajan <natarajan.sriram@gmail.com>

test/integration/discovery-etcd.bats

@@ -0,0 +1,52 @@
+#!/usr/bin/env bats
+
+load helpers
+
+# Address on which Etcd will listen (random port between 9000 and 10,000).
+ETCD_HOST=127.0.0.1:$(( ( RANDOM % 1000 )  + 9000 ))
+
+# Container name for integration test
+CONTAINER_NAME=swarm_etcd
+
+function check_leader() {
+	# Confirm Cluster leader election
+	docker_host logs $CONTAINER_NAME | grep "state changed from 'follower' to 'leader'"
+	# Check leader event
+	docker_host logs $CONTAINER_NAME | grep "leader changed from '' to"
+}
+
+function start_etcd() {
+	docker_host run -p $ETCD_HOST:4001 --name=$CONTAINER_NAME -d coreos/etcd
+	# Check if etcd cluster leader is elected
+	retry 30 1 check_leader
+}
+
+function stop_etcd() {
+	docker_host rm -f -v $CONTAINER_NAME
+}
+
+function setup() {
+	start_etcd
+}
+
+function teardown() {
+	swarm_manage_cleanup
+	swarm_join_cleanup
+	stop_docker
+	stop_etcd
+}
+
+@test "etcd discovery" {
+	# Start 2 engines and make them join the cluster.
+	start_docker 2
+	swarm_join "etcd://${ETCD_HOST}/test"
+
+	# Start a manager and ensure it sees all the engines.
+	swarm_manage "etcd://${ETCD_HOST}/test"
+	check_swarm_nodes
+
+	# Add another engine to the cluster and make sure it's picked up by swarm.
+	start_docker 1
+	swarm_join "etcd://${ETCD_HOST}/test"
+	retry 30 1 check_swarm_nodes
+}