Switch run_isolated.py to use a constant path 'ir'.

client/run_isolated.py

 #!/usr/bin/env python
 # Copyright 2012 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Runs a command with optional isolated input/output.
 
 Despite name "run_isolated", can run a generic non-isolated command specified as
 args.
 
 If input isolated hash is provided, fetches it, creates a tree of hard links,
 appends args to the command in the fetched isolated and runs it.
 To improve performance, keeps a local cache.
 The local cache can safely be deleted.
 
 Any ${EXECUTABLE_SUFFIX} on the command line will be replaced with ".exe" string
 on Windows and "" on other platforms.
 
 Any ${ISOLATED_OUTDIR} on the command line will be replaced by the location of a
 temporary directory upon execution of the command specified in the .isolated
 file. All content written to this directory will be uploaded upon termination
 and the .isolated file describing this directory will be printed to stdout.
 
 Any ${SWARMING_BOT_FILE} on the command line will be replaced by the value of
 the --bot-file parameter. This file is used by a swarming bot to communicate
 state of the host to tasks. It is written to by the swarming bot's
 on_before_task() hook in the swarming server's custom bot_config.py.
 """
 
-__version__ = '0.9'
+__version__ = '0.9.1'
 
 import argparse
 import base64
 import collections
 import contextlib
 import json
 import logging
 import optparse
 import os
 import sys
@@ skipping 355 matching lines @@
     'duration': time.time() - start,
     'items_cold': base64.b64encode(large.pack(cold)),
     'items_hot': base64.b64encode(large.pack(hot)),
   }
   return outputs_ref, success, stats
 
 
 def map_and_run(
     command, isolated_hash, storage, isolate_cache, outputs, init_named_caches,
     leak_temp_dir, root_dir, hard_timeout, grace_period, bot_file, extra_args,
-    install_packages_fn, use_symlinks):
+    install_packages_fn, use_symlinks, constant_path):

[nodir, 2017/04/06 22:58:16]

this name is generic and does not necessarily mean that this is about rundir

[M-A Ruel, 2017/04/07 15:36:33]

Changed to constant_run_path.

   """Runs a command with optional isolated input/output.
 
   See run_tha_test for argument documentation.
 
   Returns metadata about the result.
   """
   assert root_dir or root_dir is None
   assert bool(command) ^ bool(isolated_hash)
   result = {
     'duration': None,
@@ skipping 29 matching lines @@
     # },
     'outputs_ref': None,
     'version': 5,
   }
 
   if root_dir:
     file_path.ensure_tree(root_dir, 0700)
   elif isolate_cache.cache_dir:
     root_dir = os.path.dirname(isolate_cache.cache_dir)
   # See comment for these constants.
-  run_dir = make_temp_dir(ISOLATED_RUN_DIR, root_dir)
+  # If root_dir is not specified, it is not constant.

[nodir, 2017/04/06 22:58:16]

maybe return an error if constant_path is True, but root_dir is not?
currently it is rather unobvious. if root_dir is not set, but cache_dir is set,
then rundir will be constant

[M-A Ruel, 2017/04/07 15:36:33]

Not done yet because constant_run_path is hard coded to True. I added a TODO and
will revisit if there's a need.

+  if constant_path and root_dir:
+    run_dir = os.path.join(root_dir, ISOLATED_RUN_DIR)
+    os.mkdir(run_dir)
+  else:
+    run_dir = make_temp_dir(ISOLATED_RUN_DIR, root_dir)
   # storage should be normally set but don't crash if it is not. This can happen
   # as Swarming task can run without an isolate server.
   out_dir = make_temp_dir(ISOLATED_OUT_DIR, root_dir) if storage else None
   tmp_dir = make_temp_dir(ISOLATED_TMP_DIR, root_dir)
   cwd = run_dir
 
   try:
     with install_packages_fn(run_dir) as cipd_info:
       if cipd_info:
         result['stats']['cipd'] = cipd_info.stats
@@ skipping 172 matching lines @@
       'internal_failure': 'Was terminated before completion',
       'outputs_ref': None,
       'version': 5,
     }
     tools.write_json(result_json, result, dense=True)
 
   # run_isolated exit code. Depends on if result_json is used or not.
   result = map_and_run(
       command, isolated_hash, storage, isolate_cache, outputs,
       init_named_caches, leak_temp_dir, root_dir, hard_timeout, grace_period,
-      bot_file, extra_args, install_packages_fn, use_symlinks)
+      bot_file, extra_args, install_packages_fn, use_symlinks, True)
   logging.info('Result:\n%s', tools.format_json(result, dense=True))
 
   if result_json:
     # We've found tests to delete 'work' when quitting, causing an exception
     # here. Try to recreate the directory if necessary.
     file_path.ensure_tree(os.path.dirname(result_json))
     tools.write_json(result_json, result, dense=True)
     # Only return 1 if there was an internal error.
     return int(bool(result['internal_failure']))
 
@@ skipping 393 matching lines @@
     return 1
 
 
 if __name__ == '__main__':
   subprocess42.inhibit_os_error_reporting()
   # Ensure that we are always running with the correct encoding.
   fix_encoding.fix_encoding()
   file_path.enable_symlink()
 
   sys.exit(main(sys.argv[1:]))