Use safer tar extraction. Handle error messages in the build process more intelligently.

workers/dockerfilebuild.py

@@ -17,6 +17,7 @@ from data.queue import dockerfile_build_queue
 from data import model
 from workers.worker import Worker
 from app import app
+from util.safetar import safe_extractall
 
 
 root_logger = logging.getLogger('')
@@ -152,8 +153,14 @@ class DockerfileBuildContext(object):
     for status in build_status:
       fully_unwrapped = ""
       if isinstance(status, dict):
-        if len(status) > 0:
-          fully_unwrapped = status.values()[0]
+        keys_to_extract = ['error', 'status', 'stream']
+        for key in keys_to_extract:
+          if key in status:
+            fully_unwrapped = status[key]
+            break
+        
+        if not fully_unwrapped:
+          logger.debug('Status dict did not have any extractable keys and was: %s', status)
       elif isinstance(status, basestring):
         fully_unwrapped = status
 
@@ -322,7 +329,7 @@ class DockerfileBuildWorker(Worker):
 
     # Save the zip file to temp somewhere
     with tarfile.open(mode='r|*', fileobj=request_file.raw) as tar_stream:
-      tar_stream.extractall(build_dir)
+      safe_extractall(tar_stream, build_dir)
 
     return build_dir