Extract the top level zipball subdir from the zip file.

endpoints/trigger.py

@@ -1,6 +1,7 @@
 import logging
 import io
 import os.path
+import zipfile
 
 from github import Github, UnknownObjectException, GithubException
 from tempfile import SpooledTemporaryFile
@@ -228,10 +229,15 @@ class GithubBuildTrigger(BuildTrigger):
     archive_link = repo.get_archive_link('zipball', short_sha)
     download_archive = client.get(archive_link, stream=True)
 
+    zipball_subdir = ''
     with SpooledTemporaryFile(CHUNK_SIZE) as zipball:
       for chunk in download_archive.iter_content(CHUNK_SIZE):
         zipball.write(chunk)
 
+      # Pull out the name of the subdir that GitHub generated
+      with zipfile.ZipFile(zipball) as archive:
+        zipball_subdir = archive.namelist()[0]
+
       dockerfile_id = user_files.store_file(zipball, ZIPBALL)
 
     logger.debug('Successfully prepared job')
@@ -245,7 +251,6 @@ class GithubBuildTrigger(BuildTrigger):
 
     # compute the subdir
     repo_subdir = config['subdir']
-    zipball_subdir = '%s-%s-%s' % (repo.owner.login, repo.name, short_sha)
     joined_subdir = os.path.join(zipball_subdir, repo_subdir)
     logger.debug('Final subdir: %s' % joined_subdir)