Add hook to download Fuchsia SDK

build/fuchsia/update_sdk.py

+#!/usr/bin/env python
+# Copyright 2017 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.
+
+"""Updates the Fuchsia SDK to the given revision. Checks .gclient target_os
+so that it doesn't download unnecessarily."""
+
+import os
+import subprocess
+import sys
+import tarfile
+import tempfile
+
+REPOSITORY_ROOT = os.path.abspath(os.path.join(
+    os.path.dirname(__file__), '..', '..'))
+sys.path.append(os.path.join(REPOSITORY_ROOT, 'build'))
+sys.path.append(os.path.join(REPOSITORY_ROOT, 'tools', 'cr'))
+
+import cr.base

[Nico, 2017/05/11 22:31:19]

Since you're suing cr.auto and cr.loader below, shouldn't this be "import cr"?

Also, isn't cr this mostly not officially supported gclient wrapper that someone
wrote 'cause they didn't like using depot_tools directly? I'm not sure we should
use that from hooks. Do other hooks use this?

[scottmg, 2017/05/11 22:38:17]

I'd actually never heard of it before 20mins ago, I just cs'd for target_os and
it seemed like a thing to use. Should we delete it or is it just sorta
deprecated?

+import find_depot_tools
+
+
+def EnsureDirExists(path):
+  if not os.path.exists(path):
+    print 'Creating directory %s' % path
+    os.makedirs(path)
+
+
+def main():
+  if len(sys.argv) != 2:
+    print >>sys.stderr, 'usage: %s <sdk_hash>' % sys.argv[0]
+    return 1
+
+  # Check whether we're targeting Fuchsia.
+  user_path = os.path.expanduser(os.path.join('~', '.config', 'cr'))
+  cr.auto.user.__path__.append(user_path)
+  cr.loader.Scan()
+  with cr.base.context.Create(
+      description='Fuchsia SDK update tool',
+      epilog='') as context:
+
+    cr.base.client.DetectClient()
+    target_os = cr.context.gclient.get('target_os', [])

[Nico, 2017/05/11 22:31:19]

How hard is it to add hooks_os to gclient directly, like deps_os? It looks like
several of our hooks could be per-os hooks – we could move all of those android
third-party hooks out of the run-everywhere hooks for example.

[scottmg, 2017/05/11 22:38:17]

I admit I just got a little avoid-y when I landed at
https://cs.chromium.org/chromium/tools/depot_tools/gclient_eval.py?rcl=fc6905...
. I can take a look to see how involved it'd be though.

+    if 'fuchsia' not in target_os:
+      # Nothing to do.
+      return 0
+
+  sdk_hash = sys.argv[1]
+  output_dir = os.path.join(REPOSITORY_ROOT, 'third_party', 'fuchsia-sdk')
+
+  hash_filename = os.path.join(output_dir, '.hash')
+  if os.path.exists(hash_filename):
+    with open(hash_filename, 'r') as f:
+      if f.read().strip() == sdk_hash:
+        # Nothing to do.
+        return 0
+
+  print 'Downloading SDK %s...' % sdk_hash
+
+  if os.path.isdir(output_dir):
+    os.removedirs(output_dir)
+
+  bucket = 'gs://fuchsia-build/fuchsia/sdk/linux64/'
+  with tempfile.NamedTemporaryFile() as f:
+    cmd = [os.path.join(find_depot_tools.DEPOT_TOOLS_PATH, 'gsutil.py'),
+           'cp', bucket + sdk_hash, f.name]
+    print cmd
+    subprocess.check_call(cmd)
+    f.seek(0)
+    EnsureDirExists(output_dir)
+    tarfile.open(mode='r:gz', fileobj=f).extractall(path=output_dir)
+
+  with open(hash_filename, 'w') as f:
+    f.write(sdk_hash)
+
+
+if __name__ == '__main__':
+  sys.exit(main())