Change format of extra hosts

Signed-off-by: Michael Hankin <mjhankin1@gmail.com>

docker/utils/utils.py

@@ -566,7 +566,7 @@ def format_environment(environment):
 
 def format_extra_hosts(extra_hosts):
     return [
-        '{}:{}'.format(k, v) for k, v in sorted(six.iteritems(extra_hosts))
+        '{} {}'.format(v, k) for k, v in sorted(six.iteritems(extra_hosts))
     ]
 
 

tests/integration/api_service_test.py

@@ -588,8 +588,8 @@ class ServiceTest(BaseAPIIntegrationTest):
         assert 'Hosts' in svc_info['Spec']['TaskTemplate']['ContainerSpec']
         hosts = svc_info['Spec']['TaskTemplate']['ContainerSpec']['Hosts']
         assert len(hosts) == 2
-        assert 'foobar:127.0.0.1' in hosts
-        assert 'baz:8.8.8.8' in hosts
+        assert '127.0.0.1 foobar' in hosts
+        assert '8.8.8.8 baz' in hosts
 
     @requires_api_version('1.25')
     def test_create_service_with_hostname(self):

tests/unit/models_containers_test.py

@@ -141,7 +141,7 @@ class ContainerCollectionTest(unittest.TestCase):
                 'Dns': ['8.8.8.8'],
                 'DnsOptions': ['foo'],
                 'DnsSearch': ['example.com'],
-                'ExtraHosts': ['foo:1.2.3.4'],
+                'ExtraHosts': ['1.2.3.4 foo'],
                 'GroupAdd': ['blah'],
                 'IpcMode': 'foo',
                 'KernelMemory': 123,