Add a src-side script to display a summary of host info.

testing/scripts/host_info.py

Index: testing/scripts/host_info.py
diff --git a/testing/scripts/host_info.py b/testing/scripts/host_info.py
new file mode 100755
index 0000000000000000000000000000000000000000..9d785b601872be3c79ac3e07f79feb3d0797494c
--- /dev/null
+++ b/testing/scripts/host_info.py
@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+# Copyright 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.
+
+import json
+import multiprocessing
+import os
+import platform
+import subprocess
+import sys
+
+
+import common
+
+
+def is_linux():
+  return sys.platform.startswith('linux')
+
+
+def get_free_disk_space():
+  """Returns the amount of free space on the current disk, in GiB.
+
+  Returns:
+    The amount of free space on the current disk, measured in GiB.
+  """
+  if os.name == 'posix':
+    # Stat the current path for info on the current disk.
+    stat_result = os.statvfs('.')
+    # Multiply block size by number of free blocks, express in GiB.
+    return stat_result.f_frsize * stat_result.f_bavail / (
+        1024.0 / 1024.0 / 1024.0)
+
+  assert False, 'OS %s not supported.' % os.name

[Paweł Hajdan Jr., 2015/02/10 08:34:12]

I'd rather throw an exception than assert.

[shatch, 2015/02/10 16:42:57]

Removed assert and just added to the failures list.

+  return 0
+
+
+def get_num_cpus():
+  """Returns the number of logical CPUs on this machine.
+
+  Returns:
+    The number of logical CPUs on this machine, or 'unknown' if indeterminate.
+  """
+  try:
+    return multiprocessing.cpu_count()
+  except NotImplementedError:
+    return 'unknown'
+
+
+def get_device_info(args, failures):
+  """Parses the device info for each attached device, and returns a summary
+  of the device info and any mismatches.
+
+  Returns:
+    A dict indicating the result.
+  """
+  if not is_linux():
+    return {}
+
+  with common.temporary_file() as tempfile_path:
+    rc = common.run_command([
+        sys.executable,
+        os.path.join(args.paths['checkout'],
+                     'build',
+                     'android',
+                     'buildbot',
+                     'bb_device_status_check.py'),
+        '--json-output', tempfile_path])
+
+    if rc:
+      failures.append('bb_device_status_check')
+      return {}
+
+    with open(tempfile_path, 'r') as src:
+      device_info = json.load(src)
+
+  results = {}
+  results['devices'] = sorted(v['serial'] for v in device_info)
+
+  details = [v['build_detail'] for v in device_info]
+
+  parsed_details = {
+    'device_names': sorted(list(set([v.split(':')[0] for v in details]))),

[Paweł Hajdan Jr., 2015/02/10 08:34:12]

Consider extracting the common logic to a helper (sorted, set, ...); looks like
the only thing that changes is the index.

[shatch, 2015/02/10 16:42:57]

Done.

+    'build_versions': sorted(list(set([v.split(':')[1] for v in details]))),
+    'build_types': sorted(list(set([v.split(':')[2] for v in details]))),
+  }
+
+  for k, v in parsed_details.iteritems():
+    if len(v) == 1:
+      results[k] = v[0]
+    else:
+      results[k] = 'MISMATCH'
+      results['%s_list' % k] = v
+      failures.append(k)
+
+  return results
+
+
+def main_run(args):
+  failures = []
+  host_info = {}
+  host_info['os_system'] = platform.system()
+  host_info['os_release'] = platform.release()
+
+  host_info['processor'] = platform.processor()
+  host_info['num_cpus'] = get_num_cpus()
+  if host_info['num_cpus'] == 'unknown':

[Paweł Hajdan Jr., 2015/02/10 08:34:12]

Why not put this into get_num_cpus?

[shatch, 2015/02/10 16:42:57]

Done.

+    failures.append('get_num_cpus')
+
+  host_info['free_disk_space'] = get_free_disk_space()
+  if host_info['free_disk_space'] == 0:

[Paweł Hajdan Jr., 2015/02/10 08:34:12]

Why not put this into get_free_disk_space?

[shatch, 2015/02/10 16:42:57]

Done.

+    failures.append('get_free_disk_space')
+
+  host_info['python_version'] = platform.python_version()
+  host_info['python_path'] = sys.executable
+
+  host_info['devices'] = get_device_info(args, failures)
+
+  json.dump({
+      'valid': bool(not failures),
+      'failures': failures,
+      'host_info': host_info,

[shatch, 2015/02/04 15:46:18]

I'm not really clear what's allowed in the json output (if anything beyond
valid/failures?), so I tucked the host info in here for now so that it appears
on the waterfall.

[Paweł Hajdan Jr., 2015/02/10 08:34:12]

Maybe prefix it with '_' to indicate it's a custom field.

[shatch, 2015/02/10 16:42:57]

Done.

+  }, args.output)
+
+  return len(failures) != 0
+
+
+def main_compile_targets(args):
+  json.dump([], args.output)
+
+
+if __name__ == '__main__':
+  funcs = {
+    'run': main_run,
+    'compile_targets': main_compile_targets,
+  }
+  sys.exit(common.run_script(sys.argv[1:], funcs))