Merge pull request #712 from rqlite/e2e-join

End-to-end test of idempotent join

http/service.go

@@ -104,6 +104,7 @@ const (
 	numQueries    = "queries"
 	numBackups    = "backups"
 	numLoad       = "loads"
+	numJoins      = "joins"
 
 	// PermAll means all actions permitted.
 	PermAll = "all"
@@ -131,6 +132,8 @@ func init() {
 	stats.Add(numExecutions, 0)
 	stats.Add(numQueries, 0)
 	stats.Add(numBackups, 0)
+	stats.Add(numLoad, 0)
+	stats.Add(numJoins, 0)
 }
 
 // SetTime sets the Time attribute of the response. This way it will be present
@@ -251,6 +254,7 @@ func (s *Service) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		stats.Add(numLoad, 1)
 		s.handleLoad(w, r)
 	case strings.HasPrefix(r.URL.Path, "/join"):
+		stats.Add(numJoins, 1)
 		s.handleJoin(w, r)
 	case strings.HasPrefix(r.URL.Path, "/remove"):
 		s.handleRemove(w, r)

system_test/full_system_test.py

@@ -163,6 +163,9 @@ class Node(object):
   def num_snapshots(self):
     return int(self.expvar()['store']['num_snapshots'])
 
+  def num_join_requests(self):
+    return int(self.expvar()['http']['joins'])
+
   def wait_for_applied_index(self, index, timeout=TIMEOUT):
     t = 0
     while self.applied_index() < index:
@@ -352,6 +355,29 @@ class TestSingleNode(unittest.TestCase):
       time.sleep(1)
       t+=1
 
+class TestIdempotentJoin(unittest.TestCase):
+  def tearDown(self):
+    deprovision_node(self.n0)
+    deprovision_node(self.n1)
+
+  def test(self):
+    self.n0 = Node(RQLITED_PATH, '0')
+    self.n0.start()
+    self.n0.wait_for_leader()
+
+    self.n1 = Node(RQLITED_PATH, '1')
+    self.n1.start(join=self.n0.APIAddr())
+    self.n1.wait_for_leader()
+
+    self.assertEqual(self.n0.num_join_requests(), 1)
+
+    # Restart n1, and ensure it doesn't make a second join request
+    # since it's already part of the cluster.
+    self.n1.stop()
+    self.n1.start(join=self.n0.APIAddr())
+    self.n1.wait_for_leader()
+    self.assertEqual(self.n0.num_join_requests(), 1)
+
 class TestEndToEnd(unittest.TestCase):
   def setUp(self):
     n0 = Node(RQLITED_PATH, '0')