Index: trunk/packages/invirt-dev/invirt-build-conf
===================================================================
--- trunk/packages/invirt-dev/invirt-build-conf	(revision 3038)
+++ trunk/packages/invirt-dev/invirt-build-conf	(revision 3039)
@@ -7,6 +7,7 @@
 the git user that developers can push through.
 """
+from __future__ import with_statement
 
-
+import contextlib
 import os
 import tempfile
@@ -27,28 +28,29 @@
     return princ.replace('.', '/') + '@' + realm
 
+def acl_path(pocket):
+    return '/etc/remctl/acl/build-%s' % pocket
+
+@contextlib.contextmanager
+def atomic_write(file):
+    tmp_fd, tmp_name = tempfile.mkstemp()
+    tmp = os.fdopen(tmp_fd, 'r+')
+    yield tmp
+    tmp.close()
+    os.rename(tmp_name, file)
 
 def main():
     all_devs = set()
-
-    # Python could really use a file-like object that gets written to
-    # a temporary path and moved to its final resting place on
-    # .close(). Oh well.
-    conf_fd, conf_name = tempfile.mkstemp()
-    conf = os.fdopen(conf_fd, 'r+')
     build_handler = '/usr/bin/invirt-submit-build'
 
     for pocket in config.build.pockets:
         acl = authz.expandAdmin(getattr(config.build.pockets, pocket).acl, None)
+        with atomic_write(acl_path(pocket)) as f:
+            princs = [userToPrinc(a) for a in acl]
+            print >>f, '\n'.join(princs)
+            all_devs.update(set(princs))
 
-        acl_fd, acl_name = tempfile.mkstemp()
-        acl_fd = os.fdopen(acl_fd, 'r+')
-        print >>acl_fd, '\n'.join(userToPrinc(a) for a in acl)
-
-        all_devs.update(set(userToPrinc(a) for a in acl))
-
-        acl_path = os.path.join('/etc/remctl/acl/build-%s' % pocket)
-
-        os.rename(acl_name, acl_path)
-        print >>conf, 'build %s %s %s' % (pocket, build_handler, acl_path)
+    with atomic_write('/etc/remctl/conf.d/build') as f:
+        for pocket in config.build.pockets:
+            print >>f, 'build %s %s %s' % (pocket, build_handler, acl_path(pocket))
 
     os.rename(conf_name, '/etc/remctl/conf.d/build')
@@ -58,5 +60,6 @@
     print >>k5login, '\n'.join(all_devs)
 
-    os.rename(k5login_name, os.path.join(builder._REPO_DIR, '.k5login'))
+    with atomic_write(os.path.join(builder._REPO_DIR, '.k5login')) as f:
+        print >>f, '\n'.join(all_devs)