Add new --pull option in build.

Signed-off-by: Christophe Labouisse <christophe@labouisse.org>

compose/cli/main.py

@@ -153,9 +153,11 @@ class TopLevelCommand(Command):
 
         Options:
             --no-cache  Do not use cache when building the image.
+            --pull      Always attempt to pull a newer version of the image.
         """
         no_cache = bool(options.get('--no-cache', False))
-        project.build(service_names=options['SERVICE'], no_cache=no_cache)
+        pull = bool(options.get('--pull', False))
+        project.build(service_names=options['SERVICE'], no_cache=no_cache, pull=pull)
 
     def help(self, project, options):
         """

compose/project.py

@@ -257,10 +257,10 @@ class Project(object):
         for service in self.get_services(service_names):
             service.restart(**options)
 
-    def build(self, service_names=None, no_cache=False):
+    def build(self, service_names=None, no_cache=False, pull=False):
         for service in self.get_services(service_names):
             if service.can_be_built():
-                service.build(no_cache)
+                service.build(no_cache, pull)
             else:
                 log.info('%s uses an image, skipping' % service.name)
 

compose/service.py

@@ -700,7 +700,7 @@ class Service(object):
             security_opt=security_opt
         )
 
-    def build(self, no_cache=False):
+    def build(self, no_cache=False, pull=False):
         log.info('Building %s' % self.name)
 
         path = self.options['build']
@@ -714,7 +714,7 @@ class Service(object):
             tag=self.image_name,
             stream=True,
             rm=True,
-            pull=False,
+            pull=pull,
             nocache=no_cache,
             dockerfile=self.options.get('dockerfile', None),
         )

docs/reference/build.md

@@ -16,6 +16,7 @@ Usage: build [options] [SERVICE...]
 
 Options:
 --no-cache  Do not use cache when building the image.
+--pull      Always attempt to pull a newer version of the image.
 ```
 
 Services are built once and then tagged as `project_service`, e.g.,

tests/integration/cli_test.py

@@ -97,6 +97,19 @@ class CLITestCase(DockerClientTestCase):
             'Pulling digest (busybox@'
             'sha256:38a203e1986cf79639cfb9b2e1d6e773de84002feea2d4eb006b52004ee8502d)...')
 
+    @mock.patch('sys.stdout', new_callable=StringIO)
+    def test_build_plain(self, mock_stdout):
+        self.command.base_dir = 'tests/fixtures/simple-dockerfile'
+        self.command.dispatch(['build', 'simple'], None)
+
+        mock_stdout.truncate(0)
+        cache_indicator = 'Using cache'
+        pull_indicator = 'Status: Image is up to date for busybox:latest'
+        self.command.dispatch(['build', 'simple'], None)
+        output = mock_stdout.getvalue()
+        self.assertIn(cache_indicator, output)
+        self.assertNotIn(pull_indicator, output)
+
     @mock.patch('sys.stdout', new_callable=StringIO)
     def test_build_no_cache(self, mock_stdout):
         self.command.base_dir = 'tests/fixtures/simple-dockerfile'
@@ -104,14 +117,37 @@ class CLITestCase(DockerClientTestCase):
 
         mock_stdout.truncate(0)
         cache_indicator = 'Using cache'
-        self.command.dispatch(['build', 'simple'], None)
-        output = mock_stdout.getvalue()
-        self.assertIn(cache_indicator, output)
-
-        mock_stdout.truncate(0)
+        pull_indicator = 'Status: Image is up to date for busybox:latest'
         self.command.dispatch(['build', '--no-cache', 'simple'], None)
         output = mock_stdout.getvalue()
         self.assertNotIn(cache_indicator, output)
+        self.assertNotIn(pull_indicator, output)
+
+    @mock.patch('sys.stdout', new_callable=StringIO)
+    def test_build_pull(self, mock_stdout):
+        self.command.base_dir = 'tests/fixtures/simple-dockerfile'
+        self.command.dispatch(['build', 'simple'], None)
+
+        mock_stdout.truncate(0)
+        cache_indicator = 'Using cache'
+        pull_indicator = 'Status: Image is up to date for busybox:latest'
+        self.command.dispatch(['build', '--pull', 'simple'], None)
+        output = mock_stdout.getvalue()
+        self.assertIn(cache_indicator, output)
+        self.assertIn(pull_indicator, output)
+
+    @mock.patch('sys.stdout', new_callable=StringIO)
+    def test_build_no_cache_pull(self, mock_stdout):
+        self.command.base_dir = 'tests/fixtures/simple-dockerfile'
+        self.command.dispatch(['build', 'simple'], None)
+
+        mock_stdout.truncate(0)
+        cache_indicator = 'Using cache'
+        pull_indicator = 'Status: Image is up to date for busybox:latest'
+        self.command.dispatch(['build', '--no-cache', '--pull', 'simple'], None)
+        output = mock_stdout.getvalue()
+        self.assertNotIn(cache_indicator, output)
+        self.assertIn(pull_indicator, output)
 
     def test_up_detached(self):
         self.command.dispatch(['up', '-d'], None)