Add get subcommand to buildbucket.py

buildbucket.py

 #!/usr/bin/env python
 # Copyright (c) 2015 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.
 
 """Tool for interacting with Buildbucket.
 
 Usage:
   $ depot-tools-auth login https://cr-buildbucket.appspot.com
   $ buildbucket.py \
     put \
     --bucket master.tryserver.chromium.linux \
     --builder my-builder \
 
   Puts a build into buildbucket for my-builder on tryserver.chromium.linux.
 """
 
 import argparse
 import json
 import urlparse
 import os
 import sys
 
 from third_party import httplib2
 
 import auth
 
 
 BUILDBUCKET_URL = 'https://cr-buildbucket.appspot.com'
-PUT_BUILD_URL = urlparse.urljoin(
+BUILDBUCKET_API_URL = urlparse.urljoin(
   BUILDBUCKET_URL,
   '_ah/api/buildbucket/v1/builds',
 )
 
 
 def main(argv):
   parser = argparse.ArgumentParser()
   parser.add_argument(
     '-v',
     '--verbose',
     action='store_true',
   )
   subparsers = parser.add_subparsers(dest='command')
+  get_parser = subparsers.add_parser('get')
+  get_parser.add_argument(
+    '--id',
+    help='The ID of the build to get the status of.',
+    required=True,
+  )
   put_parser = subparsers.add_parser('put')
   put_parser.add_argument(
     '-b',
     '--bucket',
     help=(
       'The bucket to schedule the build on. Typically the master name, e.g.'
       ' master.tryserver.chromium.linux.'
     ),
     required=True,
   )
   put_parser.add_argument(
     '-c',
     '--changes',
     help='A flie to load a JSON list of changes dicts from.',
   )
   put_parser.add_argument(
     '-n',
     '--builder-name',
     help='The builder to schedule the build on.',
     required=True,
   )
   put_parser.add_argument(
     '-p',
     '--properties',
     help='A file to load a JSON dict of properties from.',
   )
   args = parser.parse_args()
-  # TODO(smut): When more commands are implemented, refactor this.
-  assert args.command == 'put'
 
-  changes = []
-  if args.changes:
-    try:
-      with open(args.changes) as fp:
-        changes.extend(json.load(fp))
-    except (TypeError, ValueError):
-      sys.stderr.write('%s contained invalid JSON list.\n' % args.changes)
-      raise
+  body = None
 
-  properties = {}
-  if args.properties:
-    try:
-      with open(args.properties) as fp:
-        properties.update(json.load(fp))
-    except (TypeError, ValueError):
-      sys.stderr.write('%s contained invalid JSON dict.\n' % args.properties)
-      raise
+  if args.command == 'get':
+    method = 'GET'
+    url = '%s/%s' % (BUILDBUCKET_API_URL, args.id)
+  elif args.command == 'put':
+    changes = []
+    if args.changes:
+      try:
+        with open(args.changes) as fp:
+          changes.extend(json.load(fp))
+      except (TypeError, ValueError):
+        sys.stderr.write('%s contained invalid JSON list.\n' % args.changes)
+        raise
+
+    properties = {}
+    if args.properties:
+      try:
+        with open(args.properties) as fp:
+          properties.update(json.load(fp))
+      except (TypeError, ValueError):
+        sys.stderr.write('%s contained invalid JSON dict.\n' % args.properties)
+        raise
+
+    body = json.dumps({
+      'bucket': args.bucket,
+      'parameters_json': json.dumps({
+        'builder_name': args.builder_name,
+        'changes': changes,
+        'properties': properties,
+      }),
+    })
+    method = 'PUT'
+    url = BUILDBUCKET_API_URL
 
   authenticator = auth.get_authenticator_for_host(
     BUILDBUCKET_URL,
     auth.make_auth_config(use_oauth2=True),
   )
   http = authenticator.authorize(httplib2.Http())
   http.force_exception_to_status_code = True
   response, content = http.request(
-    PUT_BUILD_URL,
-    'PUT',
-    body=json.dumps({
-      'bucket': args.bucket,
-      'parameters_json': json.dumps({
-        'builder_name': args.builder_name,
-        'changes': changes,
-        'properties': properties,
-      }),
-    }),
+    url,
+    method,
+    body=body,
     headers={'Content-Type': 'application/json'},
   )
 
   if args.verbose:
     print content
 
   return response.status != 200
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))