Use inspect network to query for an existing network.

And more tests for get_network()

Signed-off-by: Daniel Nephin <dnephin@docker.com>

compose/project.py

@@ -5,6 +5,7 @@ import logging
 from functools import reduce
 
 from docker.errors import APIError
+from docker.errors import NotFound
 
 from .config import ConfigurationError
 from .config import get_service_name_from_net
@@ -363,10 +364,10 @@ class Project(object):
         return [c for c in containers if matches_service_names(c)]
 
     def get_network(self):
-        networks = self.client.networks(names=[self.name])
-        if networks:
-            return networks[0]
-        return None
+        try:
+            return self.client.inspect_network(self.name)
+        except NotFound:
+            return None
 
     def ensure_network_exists(self):
         # TODO: recreate network if driver has changed?

tests/integration/project_test.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 from .testcases import DockerClientTestCase
+from compose.cli.docker_client import docker_client
 from compose.config import config
 from compose.const import LABEL_PROJECT
 from compose.container import Container
@@ -96,6 +97,22 @@ class ProjectTest(DockerClientTestCase):
         db = project.get_service('db')
         self.assertEqual(db._get_volumes_from(), [data_container.id + ':rw'])
 
+    def test_get_network_does_not_exist(self):
+        self.require_engine_version("1.9")
+        client = docker_client(version='1.21')
+
+        project = Project('composetest', [], client)
+        assert project.get_network() is None
+
+    def test_get_network(self):
+        self.require_engine_version("1.9")
+        client = docker_client(version='1.21')
+
+        network_name = 'network_does_exist'
+        project = Project(network_name, [], client)
+        client.create_network(network_name)
+        assert project.get_network()['name'] == network_name
+
     def test_net_from_service(self):
         project = Project.from_dicts(
             name='composetest',