Adds an 'image' property to the container model

Signed-off-by: Frank Sachsenheim <funkyfuture@riseup.net>

docker/models/containers.py

@@ -18,6 +18,16 @@ class Container(Model):
         if self.attrs.get('Name') is not None:
             return self.attrs['Name'].lstrip('/')
 
+    @property
+    def image(self):
+        """
+        The image of the container.
+        """
+        image_id = self.attrs['Image']
+        if image_id is None:
+            return None
+        return self.client.images.get(image_id.split(':')[1])
+
     @property
     def labels(self):
         """

docs/containers.rst

@@ -25,6 +25,7 @@ Container objects
   .. autoattribute:: short_id
   .. autoattribute:: name
   .. autoattribute:: status
+  .. autoattribute:: image
   .. autoattribute:: labels
   .. py:attribute:: attrs
 

tests/unit/models_containers_test.py

@@ -384,6 +384,11 @@ class ContainerTest(unittest.TestCase):
         container.get_archive('foo')
         client.api.get_archive.assert_called_with(FAKE_CONTAINER_ID, 'foo')
 
+    def test_image(self):
+        client = make_fake_client()
+        container = client.containers.get(FAKE_CONTAINER_ID)
+        assert container.image.id == FAKE_IMAGE_ID
+
     def test_kill(self):
         client = make_fake_client()
         container = client.containers.get(FAKE_CONTAINER_ID)