devtools: download shell binaries and set origin when run w/ --mojo-version.

mojo/devtools/common/devtoolslib/download.py

Index: mojo/devtools/common/devtoolslib/download.py
diff --git a/mojo/devtools/common/devtoolslib/download.py b/mojo/devtools/common/devtoolslib/download.py
new file mode 100644
index 0000000000000000000000000000000000000000..db6518feb2d0c7dbcdb6cc74fd4427578960cf8c
--- /dev/null
+++ b/mojo/devtools/common/devtoolslib/download.py
@@ -0,0 +1,99 @@
+# Copyright 2016 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 os
+import subprocess
+import sys
+import tempfile
+import urllib2
+import zipfile
+
+from devtoolslib import paths
+
+
+_SHELL_FILE_NAME = {
+    'linux-x64': 'mojo_shell',
+    'android-arm': 'MojoShell.apk'
+}
+
+
+def _get_artifacts_to_download(mojo_version, platform, verbose):
+  """Returns a list of tuples of (gs_path, file_name) to be downloaded."""
+  artifacts = []
+  shell_gs_path = ('gs://mojo/shell/%s/%s.zip' % (mojo_version, platform))
+  artifacts.append(
+      (shell_gs_path, _SHELL_FILE_NAME[platform])
+  )
+  if platform == 'linux-x64':
+    network_service_version_url = (
+        'https://raw.githubusercontent.com/domokit/mojo/' +
+        mojo_version + '/mojo/public/tools/NETWORK_SERVICE_VERSION')
+    network_service_version = (
+        urllib2.urlopen(network_service_version_url).read().strip())
+    if verbose:
+      print('Looked up the network service version for mojo at %s as: %s ' % (
+          mojo_version, network_service_version))
+
+    network_service_gs_path = (
+        'gs://mojo/network_service/%s/%s/network_service.mojo.zip' %
+        (network_service_version, platform))
+    artifacts.append(
+        (network_service_gs_path, 'network_service.mojo')
+    )
+  return artifacts
+
+
+def _download_from_gs(gs_path, output_path, depot_tools_path, verbose):
+  """Downloads the file at the given gs_path using depot_tools."""
+  # We're downloading from a public bucket which does not need authentication,
+  # but the user might have busted credential files somewhere such as ~/.boto
+  # that the gsutil script will try (and fail) to use. Setting these
+  # environment variables convinces gsutil not to attempt to use these.
+  env = os.environ.copy()
+  env['AWS_CREDENTIAL_FILE'] = ""
+  env['BOTO_CONFIG'] = ""
+
+  gsutil_exe = os.path.join(depot_tools_path, 'third_party', 'gsutil', 'gsutil')
+  if verbose:
+    print('Fetching ' + gs_path)
+
+  try:
+    subprocess.check_output(
+        [gsutil_exe,
+         '--bypass_prodaccess',
+         'cp',
+         gs_path,
+         output_path],
+        stderr=subprocess.STDOUT,
+        env=env)
+  except subprocess.CalledProcessError as e:
+    print e.output
+    sys.exit(1)
+
+
+def _extract_file(archive_path, file_name, output_dir):
+  with zipfile.ZipFile(archive_path) as z:
+    zi = z.getinfo(file_name)
+    mode = zi.external_attr >> 16
+    z.extract(zi, output_dir)
+    os.chmod(os.path.join(output_dir, file_name), mode)
+
+
+def download_shell(mojo_version, platform, root_output_dir, verbose):
+  """Downloads the shell (along with corresponding artifacts if needed) at the
+  given version.
+  """
+  depot_tools_path = paths.find_depot_tools()
+  artifacts = _get_artifacts_to_download(mojo_version, platform, verbose)
+  output_dir = os.path.join(root_output_dir, mojo_version, platform)
+
+  for (gs_path, file_name) in artifacts:
+    if os.path.isfile(os.path.join(output_dir, file_name)):
+      continue
+
+    with tempfile.NamedTemporaryFile() as temp_zip_file:
+      _download_from_gs(gs_path, temp_zip_file.name, depot_tools_path, verbose)
+      _extract_file(temp_zip_file.name, file_name, output_dir)
+
+  return os.path.join(output_dir, _SHELL_FILE_NAME[platform])