Merge branch 'samthursfield/handle-target-disk-full' of git://git.baserock.org/baserock/morph

A couple of nasties are fixed in here. Previously when the disk was
full, Morph logged a backtrace into morph.log and then tried to unmount
the disk image, but as there were still open file handles inside it
the unmount would fail and the user would end up with a backtrace for
a failed unmount and a stuck loopback device that they would need to
fix manually.

1 files changed, 21 insertions, 5 deletions

diff --git a/morphlib/bins.py b/morphlib/bins.py
index 71483172..622aa165 100644
--- a/morphlib/bins.py
+++ b/morphlib/bins.py
@@ -26,9 +26,24 @@ import os
 import re
 import errno
 import stat
+import shutil
 import tarfile
 
 
+# Work around http://bugs.python.org/issue16477
+def safe_makefile(self, tarinfo, targetpath):
+    '''Create a file, closing correctly in case of exception'''
+
+    source = self.extractfile(tarinfo)
+    try:
+        with open(targetpath, "wb") as target:
+            shutil.copyfileobj(source, target)
+    finally:
+        source.close()
+
+tarfile.TarFile.makefile = safe_makefile
+
+
 def create_chunk(rootdir, f, regexps, dump_memory_profile=None):
     '''Create a chunk from the contents of a directory.
 
@@ -187,11 +202,12 @@ def unpack_binary_from_file(f, dirname):  # pragma: no cover
     tf.makedev = monkey_patcher(tf.makedev)
     tf.makelink = monkey_patcher(tf.makelink)
 
-    tf.extractall(path=dirname)
-    tf.close
+    try:
+        tf.extractall(path=dirname)
+    finally:
+        tf.close()
 
 
 def unpack_binary(filename, dirname):
-    f = open(filename, "rb")
-    unpack_binary_from_file(f, dirname)
-    f.close()
+    with open(filename, "rb") as f:
+        unpack_binary_from_file(f, dirname)