Merge lp:~gandelman-a/nova/lp839796 into lp:~hudson-openstack/nova/trunk

[Adam Gandelman]

It seems the original 'flagfile' specified in ARGV gets recursively loaded when glfags parses argv for the first time. We can do it once before and tack on any optional flagfiles only when they exist.

One drawback to note is that optional_flagfiles does not load recursivey from nested flagfiles like '--flagfiles'

Unmerged revisions

1611. By Adam Gandelman on 2011-09-21

nova/flags.py: Use '--optional_flagfile' to specificy a flagfile that will be used
only if it exists.

Pre-parse flagfiles from FlagValues.__call_ prior to the base class, so we can check
existence of any optional_flagfiles. If the file exists, append it to argv as a
regular '--flagfile' before gflags.FlagVlues does its parsing/loading. The
original '--optional_flagfile' is then later ignored as an unknown argument
its not declared anywhere.

=== modified file 'nova/flags.py'
--- nova/flags.py	2011-09-21 20:59:40 +0000
+++ nova/flags.py	2011-09-21 23:47:23 +0000
@@ -70,6 +70,19 @@
             sneaky_unparsed_args['value'] = unparsed_args
             return optlist, unparsed_args
 
+        # preparse flagfiles for --optional_flagfile and pass
+        # as another --flagfile in argv only if it exists. the
+        # original '--optional_flagfile' argument is later ignored
+        # (LP: #839796)
+        preparse = gflags.FlagValues.ReadFlagsFromFiles(self,
+                                                        argv[1:],
+                                                        force_gnu=False)
+        for f in preparse:
+            if f.startswith("--optional_flagfile") and f.count("="):
+                flagfile = f.split("=")[1]
+                if os.path.isfile(flagfile):
+                    argv.append("--flagfile=%s" % flagfile)
+
         try:
             setattr(getopt, orig_name, _sneaky)
             args = gflags.FlagValues.__call__(self, argv)