Create proper wrapper scripts to decouple from swarm_client.

scripts/slave/trigger_swarm.py

+#!/usr/bin/env python
+# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""This script acts as the liason between the master and the swarming_client
+code.
+
+This helps with master restarts and when swarming_client is updated. It helps
+support older versions of the client code, without having to complexify the
+master code.
+"""
+
+import optparse
+import os
+import subprocess
+import sys
+
+from common import find_depot_tools  # pylint: disable=W0611
+
+# From depot tools/
+import fix_encoding
+
+
+def find_swarming_client():
+  src_swarming_client = os.path.join(
+      os.getcwd(), 'src', 'tools', 'swarming_client')
+  # This is the previous path. This can be removed around 2013-12-01.
+  src_swarm_client = os.path.join(os.getcwd(), 'src', 'tools', 'swarm_client')

[Isaac (away), 2013/08/15 23:27:01]

Ideally we wouldn't be dependent on cwd (i.e. instead passing via a
build_properties or factory_properties param).  If this is too difficult, let's
document this in top level comment.

+
+  if os.path.isdir(src_swarming_client):
+    return src_swarming_client
+  elif os.path.isdir(src_swarm_client):
+    return src_swarm_client
+
+
+def main():
+  client = find_swarming_client()
+  if not client:
+    print >> sys.stderr, 'Failed to find swarm(ing)_client'
+    return 1
+
+  # These flags are exclusively used by
+  # scripts/master/factory/swarm_commands.py.
+  parser = optparse.OptionParser()
+  parser.add_option('--os')
+  parser.add_option('--swarming')
+  parser.add_option('--prefix')
+  parser.add_option('--cac')
+  parser.add_option('--type')
+  parser.add_option('--run_from_hash', nargs=4, action='append', default=[])
+  options, args = parser.parse_args()
+  if args:
+    parser.error('Unsupported args: %s' % args)
+  cmd = [
+    sys.executable,
+    os.path.join(client, 'swarm_trigger_step.py'),
+    '-o', os,

[Isaac (away), 2013/08/15 23:27:01]

let's use long option names here if they are available.

+    '-u', options.swarming,
+    '-t', options.prefix,
+    '-d', options.cac,
+  ]
+
+  # TODO(maruel): Figure out if client support --priority.
+  if 'swarming' in client and options.type:
+    if options.type == 'ci':
+      cmd.extend(('--priority', '10'))
+    if options.type == 'cq':
+      cmd.extend(('--priority', '20'))
+    if options.type == 'fyi':
+      cmd.extend(('--priority', '30'))
+    elif options.type == 'tryjob':
+      cmd.extend(('--priority', '40'))
+
+  for i in options.run_from_hash:
+    cmd.append('--run_from_hash')
+    cmd.extend(i)
+
+  print ' '.join(cmd)
+  return subprocess.call(cmd, cwd=client)
+
+
+if __name__ == '__main__':
+  fix_encoding.fix_encoding()
+  sys.exit(main())