Fix plugin parsing for base images

If we try to add a plugin to a base image, e.g.

[neutron-base-plugin-neutron-fwaas]
type = git
location = https://github.com/openstack/neutron-fwaas
reference = master

The build will fail as it parses the above as both
"neutron-base-plugin-neutron-fwaas" and "base-plugin-neutron-fwaas".

Update the regex to ensure the image name is anchored to the beginning of the
conf section.

Change-Id: I4099ebd0d25cd28a9bb3bdc4fcfbf311ce22a3fd
Closes-Bug: #1638900

kolla/image/build.py

@@ -836,7 +836,7 @@ class KollaWorker(object):
                                             image.name)
                 image.source = process_source_installation(image, image.name)
                 for plugin in [match.group(0) for match in
-                               (re.search('{}-plugin-.+'.format(image.name),
+                               (re.search('^{}-plugin-.+'.format(image.name),
                                           section) for section in
                                 self.conf.list_all_sections()) if match]:
                     try:

kolla/tests/etc/default.conf

@@ -6,6 +6,11 @@ reference = master
 location = https://git.openstack.org/openstack/networking-arista
 type = git
 
+[neutron-base-plugin-neutron-fwaas]
+reference = master
+location = https://git.openstack.org/openstack/neutron-fwaas
+type = git
+
 [profiles]
 default = image-base
 all = image-base,image-child

kolla/tests/test_build.py

@@ -195,6 +195,24 @@ class KollaWorkerTest(base.TestCase):
         else:
             self.fail('Can not find the expected neutron arista plugin')
 
+    def test_build_image_list_plugin_parsing(self):
+        """Ensure regex used to parse plugins adds them to the correct image"""
+        self.conf.set_override('install_type', 'source')
+
+        kolla = build.KollaWorker(self.conf)
+        kolla.setup_working_dir()
+        kolla.find_dockerfiles()
+        kolla.create_dockerfiles()
+        kolla.build_image_list()
+        for image in kolla.images:
+            if image.name == 'base':
+                self.assertEqual(len(image.plugins), 0,
+                                 'base image should not have any plugins '
+                                 'registered')
+                break
+        else:
+            self.fail('Expected to find the base image in this test')
+
     def _get_matched_images(self, images):
         return [image for image in images
                 if image.status == build.STATUS_MATCHED]