Add support for copying coredumps to /tmp

tools/archive_crash.py

+#!/usr/bin/env python
+#
+# Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+#
+
+# A script that copies a core file and binary to GCS
+# We expect the dumps to be located in /tmp/coredump_PID directory
+# After we copy out the core files we delete the dumps localy
+
+import os
+import shutil
+import sys
+import subprocess
+import tarfile
+import uuid
+
+GSC_FOLDER = 'dart-crashes'

[Bill Hesse, 2014/01/29 07:01:52]

Why is this GSC_FOLDER instead of GCS_FOLDER? 

[ricow1, 2014/01/29 09:41:38]

Unintentional, fixed

+
+def CreateTarball(dir, tarname):
+  print 'Creating tar file: %s' % (tarname)
+  tar = tarfile.open(tarname, mode='w:gz')
+  tar.add(dir)
+  tar.close()
+
+def CopyToGCS(filename):
+  gs_location = 'gs://%s/%s/' % (GSC_FOLDER, uuid.uuid4())
+  cmd = ['gsutil', 'cp', filename, gs_location]

[Bill Hesse, 2014/01/29 07:01:52]

So people (all non-google users?  all non-buildbot users?) without gsutil set
up, with access to dart-crashes, should not run with the crash-dumps option?

[ricow1, 2014/01/29 09:41:38]

This script is _not_ called from tools/test.dart - test.dart will copy the
coredumps/binaries to /tmp/coredump_PID - that is it.
This is meant to be called as a separate step on the bot

+  print 'Running command: %s' % (cmd)
+  subprocess.check_call(cmd)
+  archived_filename = '%s%s' % (gs_location, filename.split('/').pop())
+  print 'Dump now available in %s' % (archived_filename) 
+
+def Main():
+  print 'Looking for crash dumps'
+  num_dumps = 0
+  for v in os.listdir('/tmp'):
+    if v.startswith('coredump'):
+      fullpath = '/tmp/%s' % (v)
+      if os.path.isdir(fullpath):
+        num_dumps += 1
+        tarname = '%s.tar.gz' % fullpath
+        CreateTarball(fullpath, tarname)
+        CopyToGCS(tarname)
+        os.unlink(tarname)

[Bill Hesse, 2014/01/29 07:01:52]

Will we not reach this if the gsutil command fails?  should we make this always
run?

[ricow1, 2014/01/29 09:41:38]

Again, this is meant to be called on the bot, if we fail to do it the bot will
go red, we still have a valid crash dump that we probably want to look at (we
can manually fetch it)

+        shutil.rmtree(fullpath)
+  print 'Found %s core dumps' % (num_dumps)
+
+if __name__ == '__main__':
+  sys.exit(Main())