Add support for log_opt

When specifying a log_driver you want to specify some options for
the logger as per the docker run --log-opt option. The logger
options are key value pairs.

Signed-off-by: Mazz Mosley <mazz@houseofmnowster.com>

compose/config.py

@@ -33,6 +33,7 @@ DOCKER_CONFIG_KEYS = [
     'memswap_limit',
     'net',
     'log_driver',
+    'log_opt',
     'pid',
     'ports',
     'privileged',

compose/service.py

@@ -40,6 +40,7 @@ DOCKER_START_KEYS = [
     'read_only',
     'net',
     'log_driver',
+    'log_opt',
     'pid',
     'privileged',
     'restart',
@@ -583,7 +584,10 @@ class Service(object):
         privileged = options.get('privileged', False)
         cap_add = options.get('cap_add', None)
         cap_drop = options.get('cap_drop', None)
-        log_config = LogConfig(type=options.get('log_driver', 'json-file'))
+        log_config = LogConfig(
+            type=options.get('log_driver', 'json-file'),
+            config=options.get('log_opt', None)
+        )
         pid = options.get('pid', None)
         security_opt = options.get('security_opt', None)
 

docs/yml.md

@@ -248,6 +248,14 @@ The default value is json-file.
     log_driver: "syslog"
     log_driver: "none"
 
+Specify logging options with `log_opt` for the logging driver, as with the ``--log-opt`` option for `docker run`.
+
+Logging options are key value pairs. An example of `syslog` options:
+
+    log_driver: "syslog"
+    log_opt:
+      address: "tcp://192.168.0.42:123"
+
 ### net
 
 Networking mode. Use the same values as the docker client `--net` parameter.

tests/unit/service_test.py

@@ -5,6 +5,7 @@ from .. import unittest
 import mock
 
 import docker
+from docker.utils import LogConfig
 
 from compose.service import Service
 from compose.container import Container
@@ -162,6 +163,16 @@ class ServiceTest(unittest.TestCase):
         self.assertEqual(opts['memswap_limit'], 2000000000)
         self.assertEqual(opts['mem_limit'], 1000000000)
 
+    def test_log_opt(self):
+        log_opt = {'address': 'tcp://192.168.0.42:123'}
+        service = Service(name='foo', image='foo', hostname='name', client=self.mock_client, log_driver='syslog', log_opt=log_opt)
+        self.mock_client.containers.return_value = []
+        opts = service._get_container_create_options({'some': 'overrides'}, 1)
+
+        self.assertIsInstance(opts['host_config']['LogConfig'], LogConfig)
+        self.assertEqual(opts['host_config']['LogConfig'].type, 'syslog')
+        self.assertEqual(opts['host_config']['LogConfig'].config, log_opt)
+
     def test_split_domainname_fqdn(self):
         service = Service(
             'foo',