add replicate() method to PostgresNode

Author: funbringer

testgres/testgres.py

@@ -872,6 +872,19 @@ def backup(self, username=None, xlog_method=DEFAULT_XLOG_METHOD):
                           username=username,
                           xlog_method=xlog_method)
 
+    def replicate(self, name, username=None, xlog_method=DEFAULT_XLOG_METHOD):
+        """
+        Create a replica of this node.
+
+        Args:
+            name: replica's name (str).
+            username: database user name (str).
+            xlog_method: a method for collecting the logs ('fetch' | 'stream').
+        """
+
+        return self.backup(username=username,
+                           xlog_method=xlog_method).spawn_replica(name)
+
     def pgbench_init(self, dbname='postgres', scale=1, options=[]):
         """
         Prepare database for pgbench (create tables etc).

tests/test_simple.py

@@ -246,6 +246,14 @@ def test_backup_and_replication(self):
                 res = replica.execute('postgres', 'select * from abc')
                 self.assertListEqual(res, [(1, 2), (3, 4)])
 
+    def test_replicate(self):
+        with get_new_node('node') as node:
+            node.init(allow_streaming=True).start()
+
+            with node.replicate(name='replica') as replica:
+                res = replica.start().execute('postgres', 'select 1')
+                self.assertListEqual(res, [(1, )])
+
     def test_dump(self):
         with get_new_node('node1') as node1:
             node1.init().start()