Expose the docker build_arg to build.py

With this implement, we can add variables at building stage.
For example, add HTTP_PROXY and NO_PROXY when needed like below.

    build.py --build-args \
        HTTP_PROXY:http://127.0.0.1:8080,NO_PROXY:127.0.0.1

More info about build_arg, pls check[0]

[0] https://docs.docker.com/engine/reference/commandline/build/#set-build-time-variables-build-arg

DocImpact

Implements: bp add-buildargs
Change-Id: I29ed7f536670fef59d697603dc562a69d90743c9

kolla/cmd/build.py

@@ -261,7 +261,8 @@ class WorkerThread(Thread):
                                       nocache=self.nocache,
                                       rm=True,
                                       pull=pull,
-                                      forcerm=self.forcerm):
+                                      forcerm=self.forcerm,
+                                      buildargs=self.conf.build_args):
             stream = json.loads(response.decode('utf-8'))
 
             if 'stream' in stream:

kolla/common/config.py

@@ -63,6 +63,8 @@ _CLI_OPTS = [
     cfg.BoolOpt('debug', short='d', default=False,
                 deprecated_group='kolla-build',
                 help='Turn on debugging log level'),
+    cfg.DictOpt('build-args',
+                help='Set docker build time variables'),
     cfg.StrOpt('include-header', short='i',
                deprecated_group='kolla-build',
                help=('Path to custom file to be added at '

kolla/tests/test_build.py

@@ -45,4 +45,22 @@ class WorkerThreadTest(base.TestCase):
 
         mock_client().build.assert_called_once_with(
             path=FAKE_IMAGE['path'], tag=FAKE_IMAGE['fullname'],
-            nocache=False, rm=True, pull=True, forcerm=True)
+            nocache=False, rm=True, pull=True, forcerm=True,
+            buildargs=None)
+
+    @mock.patch('docker.Client')
+    def test_build_image_with_build_arg(self, mock_client):
+        build_args = {
+            'HTTP_PROXY': 'http://localhost:8080',
+            'NO_PROXY': '127.0.0.1'
+        }
+        self.conf.set_override('build_args', build_args)
+        worker = build.WorkerThread(mock.Mock(),
+                                    mock.Mock(),
+                                    self.conf)
+        worker.builder(FAKE_IMAGE)
+
+        mock_client().build.assert_called_once_with(
+            path=FAKE_IMAGE['path'], tag=FAKE_IMAGE['fullname'],
+            nocache=False, rm=True, pull=True, forcerm=True,
+            buildargs=build_args)