From 07f3bd6f8c70d46978ac250403a8cc2b5a2e9175 Mon Sep 17 00:00:00 2001
From: Joseph Schorr <joseph.schorr@coreos.com>
Date: Fri, 10 Oct 2014 17:20:07 -0400
Subject: [PATCH] Add a synthetic .git directory containing the commit sha so
 that 'git rev-parse HEAD' works from inside builds

---
 endpoints/trigger.py       | 45 ++++++++++++++++++++++++++++++++++----
 workers/dockerfilebuild.py | 11 ++++++----
 2 files changed, 48 insertions(+), 8 deletions(-)

diff --git a/endpoints/trigger.py b/endpoints/trigger.py
index c7c47db79..ac3c035ba 100644
--- a/endpoints/trigger.py
+++ b/endpoints/trigger.py
@@ -3,6 +3,7 @@ import io
 import os.path
 import tarfile
 import base64
+from StringIO import StringIO
 
 from github import Github, UnknownObjectException, GithubException
 from tempfile import SpooledTemporaryFile
@@ -297,14 +298,50 @@ class GithubBuildTrigger(BuildTrigger):
       # Seek to position 0 to make tarfile happy
       tarball.seek(0)
 
-      # Pull out the name of the subdir that GitHub generated
+      # Pull out the name of the subdir that GitHub generated.
       with tarfile.open(fileobj=tarball) as archive:
-        tarball_subdir = archive.getnames()[0]
+        tarball_subdir = archive.getnames()[0]        
+        tarball_subdir_info = archive.getmember(tarball_subdir)  
 
-      # Seek to position 0 to make boto multipart happy
+      # Seek to position 0 to make tarfile happy
       tarball.seek(0)
 
-      dockerfile_id = user_files.store_file(tarball, TARBALL_MIME)
+      with SpooledTemporaryFile(CHUNK_SIZE) as updated_tarball:
+        def add_entry(arch, dir_path, base_info, contents=None):
+          info = tarfile.TarInfo(dir_path)
+
+          info.uid = base_info.uid
+          info.gid = base_info.gid
+          info.uname = base_info.uname
+          info.gname = base_info.gname
+          info.mode = base_info.mode
+          info.mtime = base_info.mtime
+
+          info.type = tarfile.REGTYPE if contents else tarfile.DIRTYPE
+          if contents:
+            info.size = len(contents)
+
+          arch.addfile(info, fileobj=StringIO(contents) if contents else None)
+
+        with tarfile.open(fileobj=updated_tarball, mode='w|gz') as updated_archive:
+          # Copy existing members of the tar to the updated archive.
+          with tarfile.open(fileobj=tarball) as archive:
+            for tar_info in archive:
+              if tar_info.isreg():
+                updated_archive.addfile(tar_info, archive.extractfile(tar_info.name))
+              else:
+                updated_archive.addfile(tar_info)
+          
+          # Add the synthetic .git directory to the tarball, containing the commit_sha.
+          add_entry(updated_archive, tarball_subdir + '/.git/HEAD', tarball_subdir_info,
+                   contents=commit_sha)
+          add_entry(updated_archive, tarball_subdir + '/.git/objects/', tarball_subdir_info)
+          add_entry(updated_archive, tarball_subdir + '/.git/refs/', tarball_subdir_info)
+
+        # Seek to position 0 to make boto multipart happy
+        updated_tarball.seek(0)
+
+        dockerfile_id = user_files.store_file(updated_tarball, TARBALL_MIME)
 
     logger.debug('Successfully prepared job')
 
diff --git a/workers/dockerfilebuild.py b/workers/dockerfilebuild.py
index 60b29a109..ceac71587 100644
--- a/workers/dockerfilebuild.py
+++ b/workers/dockerfilebuild.py
@@ -38,8 +38,7 @@ TIMEOUT_PERIOD_MINUTES = 20
 CACHE_EXPIRATION_PERIOD_HOURS = 24
 NO_TAGS = ['<none>:<none>']
 RESERVATION_TIME = (TIMEOUT_PERIOD_MINUTES + 5) * 60
-DOCKER_BASE_URL = None # Set this if you want to use a different docker URL/socket.
-
+DOCKER_BASE_URL = os.environ.get('DOCKER_HOST', None)
 
 def matches_system_error(status_str):
   """ Returns true if the given status string matches a known system error in the
@@ -521,8 +520,12 @@ class DockerfileBuildWorker(Worker):
                            repository_build.uuid)
 
     # Lookup and save the version of docker being used.
-    docker_cl = Client(base_url = DOCKER_BASE_URL)
-    docker_version = docker_cl.version().get('Version', '')
+    try:
+      docker_cl = Client(base_url = DOCKER_BASE_URL)
+      docker_version = docker_cl.version().get('Version', '')
+    except ConnectionError as exc:
+      raise WorkerUnhealthyException(exc.message)
+
     dash = docker_version.find('-')
 
     # Strip any -tutum or whatever off of the version.