Allow scaling services that have port binding of the form host_ip::container_port

compose/service.py

@@ -770,10 +770,28 @@ def custom_container_name(self):
         return self.options.get('container_name')
 
     def specifies_host_port(self):
-        for port in self.options.get('ports', []):
-            if ':' in str(port):
+        def has_host_port(binding):
+            _, external_bindings = split_port(binding)
+
+            # there are no external bindings
+            if external_bindings is None:
+                return False
+
+            # we only need to check the first binding from the range
+            external_binding = external_bindings[0]
+
+            # non-tuple binding means there is a host port specified
+            if not isinstance(external_binding, tuple):
                 return True
-        return False
+
+            # extract actual host port from tuple of (host_ip, host_port)
+            _, host_port = external_binding
+            if host_port is not None:
+                return True
+
+            return False
+
+        return any(has_host_port(binding) for binding in self.options.get('ports', []))
 
     def pull(self, ignore_pull_failures=False):
         if 'image' not in self.options:

tests/unit/service_test.py

@@ -444,6 +444,68 @@ def test_config_dict_with_net_from_container(self):
         }
         self.assertEqual(config_dict, expected)
 
+    def test_specifies_host_port_with_no_ports(self):
+        service = Service(
+            'foo',
+            image='foo')
+        self.assertEqual(service.specifies_host_port(), False)
+
+    def test_specifies_host_port_with_container_port(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["2000"])
+        self.assertEqual(service.specifies_host_port(), False)
+
+    def test_specifies_host_port_with_host_port(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["1000:2000"])
+        self.assertEqual(service.specifies_host_port(), True)
+
+    def test_specifies_host_port_with_host_ip_no_port(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["127.0.0.1::2000"])
+        self.assertEqual(service.specifies_host_port(), False)
+
+    def test_specifies_host_port_with_host_ip_and_port(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["127.0.0.1:1000:2000"])
+        self.assertEqual(service.specifies_host_port(), True)
+
+    def test_specifies_host_port_with_container_port_range(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["2000-3000"])
+        self.assertEqual(service.specifies_host_port(), False)
+
+    def test_specifies_host_port_with_host_port_range(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["1000-2000:2000-3000"])
+        self.assertEqual(service.specifies_host_port(), True)
+
+    def test_specifies_host_port_with_host_ip_no_port_range(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["127.0.0.1::2000-3000"])
+        self.assertEqual(service.specifies_host_port(), False)
+
+    def test_specifies_host_port_with_host_ip_and_port_range(self):
+        service = Service(
+            'foo',
+            image='foo',
+            ports=["127.0.0.1:1000-2000:2000-3000"])
+        self.assertEqual(service.specifies_host_port(), True)
+
 
 class NetTestCase(unittest.TestCase):