Add Services.ip_for method to obtain IP of container

src/pytest_docker/__init__.py

@@ -8,6 +8,7 @@
 import subprocess
 import time
 import timeit
+import json
 
 
 def execute(command, success_codes=(0,)):
@@ -101,6 +102,36 @@ def wait_until_responsive(self, check, timeout, pause,
             'Timeout reached while waiting on service!'
         )
 
+    def ip_for(self, service):
+        """Get direct IP of container"""
+        # List containers providing given service
+        containers_ids = self._docker_compose.execute(
+            "ps -q %s" % service).strip().splitlines()
+        if len(containers_ids) == 0:
+            raise ValueError(
+                "Can not find container for service '%s'" % service)
+        if len(containers_ids) > 1:
+            raise Exception(
+                "Multiple containers (%d) for one service '%s' detected"
+                % (len(containers_ids), service))
+
+        # Read out info about listed container
+        docker_info = json.loads(
+            execute("docker inspect %s" % containers_ids[0])
+        )
+        if not docker_info:
+            raise Exception(
+                "Couldn't fetch information data about container %s "
+                % containers_ids[0])
+        network_settings = docker_info[0]['NetworkSettings']
+        networks = network_settings['Networks']
+        if not networks:
+            raise Exception(
+                "Container %s doesn't have network attached"
+                % containers_ids[0])
+        for i in networks.values():
+            return i['IPAddress']
+
 
 def str_to_list(arg):
     if isinstance(arg, (list, tuple)):

tests/requirements.in

@@ -6,3 +6,4 @@ flake8
 mock
 pytest
 requests
+docker-compose

tests/test_integration.py

@@ -38,3 +38,8 @@ def test_integration(docker_ip, docker_services):
     response = requests.get(url)
     response.raise_for_status()
     print(response.text)
+
+
+def test_direct_ip(docker_ip, docker_services):
+    ip = docker_services.ip_for('hello')
+    assert len(ip.split('.')) == 4