Add a clone_repository function.

ci/jobgenerator.py

@@ -15,5 +15,38 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+import git
+from os import getenv
+from yaml import CLoader
+from yaml import load as yaml_load
+from shutil import rmtree
+from tempfile import mkdtemp
+
+class Generator:
+    def clone_repository(self):
+        # Assuming this is ran inside Jenkins, this fetches the env vars set in
+        # the job config. If those don't exist, we need to throw an error,
+        # because otherwise we have no metadata to actually pull from
+        metadata_url = getenv("METADATA_URL")
+        metadata_repo_name = getenv("METADATA_REPO_NAME")
+        if not metadata_url or metadata_url == "" or not metadata_repo_name \
+            or metadata_repo_name == "":
+            raise ValueError("METADATA_URL and METADATA_REPO_NAME must be set")
+
+        # Create a temporary directory in the most secure manner possible and
+        # clone the metadata, throwing the directory away when we're done
+        try:
+            metadata_loc = mkdtemp()
+            git.Git(metadata_loc).clone(metadata_url)
+
+            # Load ci.conf and parse it
+            with open(metadata_loc + "/" + metadata_repo_name + "/ci.conf") \
+                as metadata_conf_file:
+                metadata_conf = yaml_load(metadata_conf_file, Loader=CLoader)
+        finally:
+            rmtree(metadata_loc)
+
+
 if __name__ == "__main__":
-    print("Hello world!")
+    generator = Generator()
+    generator.clone_repository()