Resolves #447, fix volume logic for recreate container

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

Author: dnephin

fig/project.py

@@ -181,8 +181,8 @@ def up(self,
 
             for container in create_func(
                     insecure_registry=insecure_registry,
-                        detach=detach,
-                        do_build=do_build):
+                    detach=detach,
+                    do_build=do_build):
                 running_containers.append(container)
 
         return running_containers

fig/service.py

@@ -280,23 +280,29 @@ def recreate_container(self, container, **override_options):
             else:
                 raise
 
+        intermediate_options = dict(self.options, **override_options)
         intermediate_container = Container.create(
             self.client,
             image=container.image,
             entrypoint=['/bin/echo'],
             command=[],
             detach=True,
         )
-        intermediate_container.start(volumes_from=container.id)
+        intermediate_container.start(
+            binds=get_container_data_volumes(
+                container, intermediate_options.get('volumes')))
         intermediate_container.wait()
         container.remove()
 
+        # TODO: volumes are being passed to both start and create, this is
+        # probably unnecessary
         options = dict(override_options)
         new_container = self.create_container(do_build=False, **options)
-        self.start_container(new_container, intermediate_container=intermediate_container)
+        self.start_container(
+            new_container,
+            intermediate_container=intermediate_container)
 
         intermediate_container.remove()
-
         return new_container
 
     def start_container_if_stopped(self, container, **options):
@@ -309,12 +315,6 @@ def start_container_if_stopped(self, container, **options):
     def start_container(self, container, intermediate_container=None, **override_options):
         options = dict(self.options, **override_options)
         port_bindings = build_port_bindings(options.get('ports') or [])
-
-        volume_bindings = dict(
-            build_volume_binding(parse_volume_spec(volume))
-            for volume in options.get('volumes') or []
-            if ':' in volume)
-
         privileged = options.get('privileged', False)
         net = options.get('net', 'bridge')
         dns = options.get('dns', None)
@@ -323,12 +323,14 @@ def start_container(self, container, intermediate_container=None, **override_opt
         cap_drop = options.get('cap_drop', None)
 
         restart = parse_restart_spec(options.get('restart', None))
+        binds = get_volume_bindings(
+            options.get('volumes'), intermediate_container)
 
         container.start(
             links=self._get_links(link_to_self=options.get('one_off', False)),
             port_bindings=port_bindings,
-            binds=volume_bindings,
-            volumes_from=self._get_volumes_from(intermediate_container),
+            binds=binds,
+            volumes_from=self._get_volumes_from(),
             privileged=privileged,
             network_mode=net,
             dns=dns,
@@ -390,7 +392,7 @@ def _get_links(self, link_to_self):
             links.append((external_link, link_name))
         return links
 
-    def _get_volumes_from(self, intermediate_container=None):
+    def _get_volumes_from(self):
         volumes_from = []
         for volume_source in self.volumes_from:
             if isinstance(volume_source, Service):
@@ -404,9 +406,6 @@ def _get_volumes_from(self, intermediate_container=None):
             elif isinstance(volume_source, Container):
                 volumes_from.append(volume_source.id)
 
-        if intermediate_container:
-            volumes_from.append(intermediate_container.id)
-
         return volumes_from
 
     def _get_container_create_options(self, override_options, one_off=False):
@@ -521,6 +520,45 @@ def pull(self, insecure_registry=False):
             )
 
 
+def get_container_data_volumes(container, volumes_option):
+    """Find the container data volumes that are in `volumes_option`, and return
+    a mapping of volume bindings for those volumes.
+    """
+    volumes = []
+    for volume in volumes_option or []:
+        volume = parse_volume_spec(volume)
+        # No need to preserve host volumes
+        if volume.external:
+            continue
+
+        volume_path = (container.get('Volumes') or {}).get(volume.internal)
+        # New volume, doesn't exist in the old container
+        if not volume_path:
+            continue
+
+        # Copy existing volume from old container
+        volume = volume._replace(external=volume_path)
+        volumes.append(build_volume_binding(volume))
+
+    return dict(volumes)
+
+
+def get_volume_bindings(volumes_option, intermediate_container):
+    """Return a list of volume bindings for a container. Container data volume
+    bindings are replaced by those in the intermediate container.
+    """
+    volume_bindings = dict(
+        build_volume_binding(parse_volume_spec(volume))
+        for volume in volumes_option or []
+        if ':' in volume)
+
+    if intermediate_container:
+        volume_bindings.update(
+            get_container_data_volumes(intermediate_container, volumes_option))
+
+    return volume_bindings
+
+
 NAME_RE = re.compile(r'^([^_]+)_([^_]+)_(run_)?(\d+)$')
 
 

tests/integration/service_test.py

@@ -98,7 +98,7 @@ def test_create_container_with_unspecified_volume(self):
         service = self.create_service('db', volumes=['/var/db'])
         container = service.create_container()
         service.start_container(container)
-        self.assertIn('/var/db', container.inspect()['Volumes'])
+        self.assertIn('/var/db', container.get('Volumes'))
 
     def test_create_container_with_cpu_shares(self):
         service = self.create_service('db', cpu_shares=73)
@@ -179,6 +179,16 @@ def test_recreate_containers_when_containers_are_stopped(self):
         service.recreate_containers()
         self.assertEqual(len(service.containers(stopped=True)), 1)
 
+    def test_recreate_containers_with_volume_changes(self):
+        service = self.create_service('withvolumes', volumes=['/etc'])
+        old_container = create_and_start_container(service)
+        self.assertEqual(old_container.get('Volumes').keys(), ['/etc'])
+
+        service = self.create_service('withvolumes')
+        container, = service.recreate_containers()
+        service.start_container(container)
+        self.assertEqual(container.get('Volumes'), {})
+
     def test_start_container_passes_through_options(self):
         db = self.create_service('db')
         create_and_start_container(db, environment={'FOO': 'BAR'})

tests/unit/service_test.py

@@ -11,13 +11,15 @@
 from fig import Service
 from fig.container import Container
 from fig.service import (
+    APIError,
     ConfigError,
-    split_port,
     build_port_bindings,
-    parse_volume_spec,
     build_volume_binding,
-    APIError,
+    get_container_data_volumes,
+    get_volume_bindings,
     parse_repository_tag,
+    parse_volume_spec,
+    split_port,
 )
 
 
@@ -57,13 +59,6 @@ def test_get_volumes_from_container(self):
 
         self.assertEqual(service._get_volumes_from(), [container_id])
 
-    def test_get_volumes_from_intermediate_container(self):
-        container_id = 'aabbccddee'
-        service = Service('test')
-        container = mock.Mock(id=container_id, spec=Container)
-
-        self.assertEqual(service._get_volumes_from(container), [container_id])
-
     def test_get_volumes_from_service_container_exists(self):
         container_ids = ['aabbccddee', '12345']
         from_service = mock.create_autospec(Service)
@@ -288,6 +283,50 @@ def test_building_volume_binding_with_home(self):
             binding,
             ('/home/user', dict(bind='/home/user', ro=False)))
 
+    def test_get_container_data_volumes(self):
+        options = [
+            '/host/volume:/host/volume:ro',
+            '/new/volume',
+            '/existing/volume',
+        ]
+
+        container = Container(None, {
+            'Volumes': {
+                '/host/volume':     '/host/volume',
+                '/existing/volume': '/var/lib/docker/aaaaaaaa',
+                '/removed/volume':  '/var/lib/docker/bbbbbbbb',
+            },
+        }, has_been_inspected=True)
+
+        expected = {
+            '/var/lib/docker/aaaaaaaa': {'bind': '/existing/volume', 'ro': False},
+        }
+
+        binds = get_container_data_volumes(container, options)
+        self.assertEqual(binds, expected)
+
+    def test_get_volume_bindings(self):
+        options = [
+            '/host/volume:/host/volume:ro',
+            '/host/rw/volume:/host/rw/volume',
+            '/new/volume',
+            '/existing/volume',
+        ]
+
+        intermediate_container = Container(None, {
+            'Volumes': {'/existing/volume': '/var/lib/docker/aaaaaaaa'},
+            }, has_been_inspected=True)
+
+        expected = {
+            '/host/volume': {'bind': '/host/volume', 'ro': True},
+            '/host/rw/volume': {'bind': '/host/rw/volume', 'ro': False},
+            '/var/lib/docker/aaaaaaaa': {'bind': '/existing/volume', 'ro': False},
+        }
+
+        binds = get_volume_bindings(options, intermediate_container)
+        self.assertEqual(binds, expected)
+
+
 class ServiceEnvironmentTest(unittest.TestCase):
 
     def setUp(self):