Add feature to ctest that allows it to run against the latest image if no latest candidate exists.

ctest/ctest.py

 #!/usr/bin/python
 #
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Wrapper for tests that are run on builders."""
 
 import fileinput
 import optparse
@@ skipping 125 matching lines @@
 
   zip_dir = os.path.join(zip_base, latest_version)
   zip_name = GetLatestLinkFromPage(zip_dir,
                                    'ChromeOS-\d+\.\d+\.\d+\.\d+-.*\.zip')
   return os.path.join(zip_dir, zip_name)
 
 
 def GetLatestZipUrl(board, channel, zip_server_base):
   """Returns the url of the latest image zip for the given arguments.
 
-  If the latest does not exist, tries to find the rc equivalent.
+  If the latest does not exist, tries to find the rc equivalent.  If neither
+  exist, returns None.
 
   Args:
     board: board for the image zip.
     channel: channel for the image zip.
     zip_server_base:  base url for zipped images.
   """
   try:
     return GetNewestLinkFromZipBase(board, channel, zip_server_base)
   except:
-    cros_lib.Warning('Failed to get url from standard zip base.  Trying rc.')
+    cros_lib.Warning('Failed to get url from zip base.')
+  try:
     return GetNewestLinkFromZipBase(board + '-rc', channel, zip_server_base)
+  except:

[dgarrett, 2011/04/05 23:36:38]

I know you're just following pattern, but these really should specify which
exception to grab....

+    cros_lib.Warning('Failed to get url from zip base for release candidates.')
+    return None
 
 
 def GrabZipAndExtractImage(zip_url, download_folder, image_name) :
   """Downloads the zip and extracts the given image.
 
   Doesn't re-download if matching version found already in download folder.
   Args:
     zip_url - url for the image.
     download_folder - download folder to store zip file and extracted images.
     image_name - name of the image to extract from the zip file.
@@ skipping 67 matching lines @@
     board: the board for the latest image.
     channel: the channel to run the au test harness against.
     zip_server_base:  base url for zipped images.
     no_graphics: boolean - If True, disable graphics during vm test.
     type: which test harness to run.  Possible values: real, vm.
     remote: ip address for real test harness run.
     clean: Clean the state of test harness before running.
     test_results_root: Root directory to store au_test_harness results.
   """
   crosutils_root = os.path.join(constants.SOURCE_ROOT, 'src', 'scripts')
+
+  # Grab the latest image we've built.
+  return_object = cros_lib.RunCommand(
+    ['./get_latest_image.sh', '--board=%s' % board], cwd=crosutils_root,
+    redirect_stdout=True, print_cmd=True)
+
+  latest_image_dir = return_object.output.strip()
+  target_image = os.path.join(latest_image_dir, _IMAGE_TO_EXTRACT)
+
+  # Grab the latest official build for this board to use as the base image.
+  # If it doesn't exist, run the update test against itself.
   download_folder = os.path.abspath('latest_download')
   zip_url = GetLatestZipUrl(board, channel, zip_server_base)
-  GrabZipAndExtractImage(zip_url, download_folder, _IMAGE_TO_EXTRACT)
 
-  # Tests go here.
-  return_object = cros_lib.RunCommand(
-      ['./get_latest_image.sh', '--board=%s' % board], cwd=crosutils_root,
-      redirect_stdout=True, print_cmd=True)
-
-  latest_image = return_object.output.strip()
+  base_image = None
+  if zip_url:
+    GrabZipAndExtractImage(zip_url, download_folder, _IMAGE_TO_EXTRACT)
+    base_image = os.path.join(download_folder, _IMAGE_TO_EXTRACT)
+  else:
+    base_image = target_image
 
   update_engine_path = os.path.join(crosutils_root, '..', 'platform',
                                     'update_engine')
 
   private_key_path = os.path.join(update_engine_path, 'unittest_key.pem')
   public_key_path = GeneratePublicKey(private_key_path)
 
   cmd = ['bin/cros_au_test_harness',
-         '--base_image=%s' % os.path.join(download_folder,
-                                          _IMAGE_TO_EXTRACT),
-         '--target_image=%s' % os.path.join(latest_image,
-                                            _IMAGE_TO_EXTRACT),
+         '--base_image=%s' % base_image,
+         '--target_image=%s' % target_image,
          '--board=%s' % board,
          '--type=%s' % type,
          '--remote=%s' % remote,
          '--private_key=%s' % private_key_path,
          '--public_key=%s' % public_key_path,
          ]
   if test_results_root: cmd.append('--test_results_root=%s' % test_results_root)
   if no_graphics: cmd.append('--no_graphics')
   if clean: cmd.append('--clean')
 
@@ skipping 30 matching lines @@
   if not options.zipbase: parser.error('Need zip url base to get images.')
 
   RunAUTestHarness(options.board, options.channel, options.zipbase,
                    options.no_graphics, options.type, options.remote,
                    not options.cache, options.test_results_root)
 
 
 if __name__ == '__main__':
   main()