add worlddump tool to devstack

when we exit poorly, start building a tool for doing a capture
as to why. This tool is expected to be consumed directly from
grenade as well.

Change-Id: Ia1bc1c2e259587035ca7252baceec25fa464cb82

stack.sh

@@ -622,6 +622,11 @@ function exit_trap {
     # Kill the last spinner process
     kill_spinner
 
+    if [[ $r -ne 0 ]]; then
+        echo "Error on exit"
+        ./tools/worlddump.py -d $LOGDIR
+    fi
+
     exit $r
 }
 

tools/worlddump.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python
+#
+# Copyright 2014 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""Dump the state of the world for post mortem."""
+
+import argparse
+import datetime
+import os
+import os.path
+import sys
+
+
+def get_options():
+    parser = argparse.ArgumentParser(
+        description='Dump world state for debugging')
+    parser.add_argument('-d', '--dir',
+                        default='.',
+                        help='Output directory for worlddump')
+    return parser.parse_args()
+
+
+def filename(dirname):
+    now = datetime.datetime.utcnow()
+    return os.path.join(dirname, now.strftime("worlddump-%Y-%m-%d-%H%M%S.txt"))
+
+
+def warn(msg):
+    print "WARN: %s" % msg
+
+
+def disk_space():
+    # the df output
+    print """
+File System Summary
+===================
+"""
+    dfraw = os.popen("df -Ph").read()
+    df = [s.split() for s in dfraw.splitlines()]
+    for fs in df:
+        try:
+            if int(fs[4][:-1]) > 95:
+                warn("Device %s (%s) is %s full, might be an issue" % (
+                    fs[0], fs[5], fs[4]))
+        except ValueError:
+            # if it doesn't look like an int, that's fine
+            pass
+
+    print dfraw
+
+
+def process_list():
+    print """
+Process Listing
+===============
+"""
+    psraw = os.popen("ps auxw").read()
+    print psraw
+
+
+def main():
+    opts = get_options()
+    fname = filename(opts.dir)
+    print "World dumping... see %s for details" % fname
+    sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)
+    with open(fname, 'w') as f:
+        os.dup2(f.fileno(), sys.stdout.fileno())
+        disk_space()
+        process_list()
+
+
+if __name__ == '__main__':
+    try:
+        sys.exit(main())
+    except KeyboardInterrupt:
+        sys.exit(1)