[image-build] Allow dynamic release for images

When the release is explicitly set to None, generate a value from date
and respin. The documentation is updated to explain how it works.

Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

doc/configuration.rst

@@ -660,10 +660,13 @@ Image Build Settings
     Config can contain anything what is accepted by
     ``koji image-build --config configfile.ini``
 
-    Repo can be specified either as a string or a list of strings. It will
+    Repo can be specified either as a string or a list of strings. It will be
     automatically transformed into format suitable for ``koji``. A repo for the
     currently built variant will be added as well.
 
+    If you explicitly set ``release`` to ``None``, it will be replaced with
+    ``DATE.RESPIN`` of the current compose.
+
     You can also add extra variants to get repos from with key ``repo_from``.
     The value should be a list of variant names.
 
@@ -698,7 +701,7 @@ Example
                 'disk_size': 3,
 
                 # this is set automatically by pungi to os_dir for given variant
-                # 'install_tree': 'http://sometpath',
+                # 'install_tree': 'http://somepath',
             },
             {
                 'format': [('qcow2','qcow2')]
@@ -716,6 +719,9 @@ Example
                 # Use install tree and repo from Everything variant.
                 'install_tree_from': 'Everything',
                 'repo_from': ['Everything'],
+
+                # Set release based on date and respin.
+                'release': None,
             }
         ]
     }

pungi/phases/image_build.py

@@ -77,6 +77,11 @@ class ImageBuildPhase(PhaseBase):
             arches = set(image_conf.get('arches', [])) & arches
         return ','.join(sorted(arches))
 
+    def _set_release(self, image_conf):
+        """If release is set explicitly to None, replace it with date and respin."""
+        if 'release' in image_conf and image_conf['release'] is None:
+            image_conf['release'] = '%s.%s' % (self.compose.compose_date, self.compose.compose_respin)
+
     def run(self):
         for variant in self.compose.get_variants():
             arches = set([x for x in variant.arches if x != 'src'])
@@ -101,6 +106,8 @@ class ImageBuildPhase(PhaseBase):
 
                 image_conf["install_tree"] = self._get_install_tree(image_conf, variant)
 
+                self._set_release(image_conf)
+
                 # transform format into right 'format' for image-build
                 # e.g. 'docker,qcow2'
                 format = image_conf["format"]

tests/test_imagebuildphase.py

@@ -282,6 +282,40 @@ class TestImageBuildPhase(unittest.TestCase):
             "link_type": 'hardlink-or-copy',
         })
 
+    @mock.patch('pungi.phases.image_build.ThreadPool')
+    def test_image_build_create_release(self, ThreadPool):
+        compose = _DummyCompose({
+            'image_build': {
+                '^Server$': [
+                    {
+                        'format': [('docker', 'tar.xz')],
+                        'name': 'Fedora-Docker-Base',
+                        'target': 'f24',
+                        'version': 'Rawhide',
+                        'ksurl': 'git://git.fedorahosted.org/git/spin-kickstarts.git',
+                        'kickstart': "fedora-docker-base.ks",
+                        'distro': 'Fedora-20',
+                        'disk_size': 3,
+                        'arches': ['x86_64'],
+                        'release': None,
+                    }
+                ]
+            },
+            'koji_profile': 'koji',
+        })
+
+        phase = ImageBuildPhase(compose)
+
+        phase.run()
+
+        # assert at least one thread was started
+        self.assertTrue(phase.pool.add.called)
+
+        self.assertTrue(phase.pool.queue_put.called_once)
+        args, kwargs = phase.pool.queue_put.call_args
+        self.assertEqual(args[0][1].get('image_conf', {}).get('release'),
+                         '20151203.0')
+
 
 class TestCreateImageBuildThread(unittest.TestCase):