Support version 3.0 of the Compose file format

Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>

tests/acceptance/cli_test.py

@@ -285,6 +285,61 @@ class CLITestCase(DockerClientTestCase):
             'volumes': {},
         }
 
+    def test_config_v3(self):
+        self.base_dir = 'tests/fixtures/v3-full'
+        result = self.dispatch(['config'])
+
+        assert yaml.load(result.stdout) == {
+            'version': '3.0',
+            'networks': {},
+            'volumes': {},
+            'services': {
+                'web': {
+                    'image': 'busybox',
+                    'deploy': {
+                        'mode': 'replicated',
+                        'replicas': 6,
+                        'labels': ['FOO=BAR'],
+                        'update_config': {
+                            'parallelism': 3,
+                            'delay': '10s',
+                            'failure_action': 'continue',
+                            'monitor': '60s',
+                            'max_failure_ratio': 0.3,
+                        },
+                        'resources': {
+                            'limits': {
+                                'cpus': '0.001',
+                                'memory': '50M',
+                            },
+                            'reservations': {
+                                    'cpus': '0.0001',
+                                    'memory': '20M',
+                            },
+                        },
+                        'restart_policy': {
+                            'condition': 'on_failure',
+                            'delay': '5s',
+                            'max_attempts': 3,
+                            'window': '120s',
+                        },
+                        'placement': {
+                            'constraints': ['node=foo'],
+                        },
+                    },
+
+                    'healthcheck': {
+                        'command': 'cat /etc/passwd',
+                        'interval': '10s',
+                        'timeout': '1s',
+                        'retries': 5,
+                    },
+
+                    'stop_grace_period': '20s',
+                },
+            },
+        }
+
     def test_ps(self):
         self.project.get_service('simple').create_container()
         result = self.dispatch(['ps'])

tests/fixtures/v3-full/docker-compose.yml

@@ -0,0 +1,37 @@
+version: "3"
+services:
+  web:
+    image: busybox
+
+    deploy:
+      mode: replicated
+      replicas: 6
+      labels: [FOO=BAR]
+      update_config:
+        parallelism: 3
+        delay: 10s
+        failure_action: continue
+        monitor: 60s
+        max_failure_ratio: 0.3
+      resources:
+        limits:
+          cpus: '0.001'
+          memory: 50M
+        reservations:
+          cpus: '0.0001'
+          memory: 20M
+      restart_policy:
+        condition: on_failure
+        delay: 5s
+        max_attempts: 3
+        window: 120s
+      placement:
+        constraints: [node=foo]
+
+    healthcheck:
+      command: cat /etc/passwd
+      interval: 10s
+      timeout: 1s
+      retries: 5
+
+    stop_grace_period: 20s

tests/unit/config/config_test.py

@@ -18,6 +18,7 @@ from compose.config.config import resolve_environment
 from compose.config.config import V1
 from compose.config.config import V2_0
 from compose.config.config import V2_1
+from compose.config.config import V3_0
 from compose.config.environment import Environment
 from compose.config.errors import ConfigurationError
 from compose.config.errors import VERSION_EXPLANATION
@@ -156,9 +157,14 @@ class ConfigTest(unittest.TestCase):
         for version in ['2', '2.0']:
             cfg = config.load(build_config_details({'version': version}))
             assert cfg.version == V2_0
+
         cfg = config.load(build_config_details({'version': '2.1'}))
         assert cfg.version == V2_1
 
+        for version in ['3', '3.0']:
+            cfg = config.load(build_config_details({'version': version}))
+            assert cfg.version == V3_0
+
     def test_v1_file_version(self):
         cfg = config.load(build_config_details({'web': {'image': 'busybox'}}))
         assert cfg.version == V1