1 files changed, 297 insertions, 0 deletions
diff --git a/src/util/bot/go/bootstrap.py b/src/util/bot/go/bootstrap.py
new file mode 100755
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--- /dev/null
+++ b/src/util/bot/go/bootstrap.py
@@ -0,0 +1,297 @@
+#!/usr/bin/env python
+# Copyright 2014 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.
+
+# Modified from go/bootstrap.py in Chromium infrastructure's repository to patch
+# out everything but the core toolchain.
+#
+# https://chromium.googlesource.com/infra/infra/
+
+"""Prepares a local hermetic Go installation.
+
+- Downloads and unpacks the Go toolset in ../golang.
+"""
+
+import contextlib
+import logging
+import os
+import platform
+import shutil
+import stat
+import subprocess
+import sys
+import tarfile
+import tempfile
+import urllib
+import zipfile
+
+# TODO(vadimsh): Migrate to new golang.org/x/ paths once Golang moves to
+# git completely.
+
+LOGGER = logging.getLogger(__name__)
+
+
+# /path/to/util/bot
+ROOT = os.path.dirname(os.path.abspath(__file__))
+
+# Where to install Go toolset to. GOROOT would be <TOOLSET_ROOT>/go.
+TOOLSET_ROOT = os.path.join(os.path.dirname(ROOT), 'golang')
+
+# Default workspace with infra go code.
+WORKSPACE = os.path.join(ROOT, 'go')
+
+# Platform depended suffix for executable files.
+EXE_SFX = '.exe' if sys.platform == 'win32' else ''
+
+# Pinned version of Go toolset to download.
+TOOLSET_VERSION = 'go1.4'
+
+# Platform dependent portion of a download URL. See http://golang.org/dl/.
+TOOLSET_VARIANTS = {
+  ('darwin', 'x86-32'): 'darwin-386-osx10.8.tar.gz',
+  ('darwin', 'x86-64'): 'darwin-amd64-osx10.8.tar.gz',
+  ('linux2', 'x86-32'): 'linux-386.tar.gz',
+  ('linux2', 'x86-64'): 'linux-amd64.tar.gz',
+  ('win32', 'x86-32'): 'windows-386.zip',
+  ('win32', 'x86-64'): 'windows-amd64.zip',
+}
+
+# Download URL root.
+DOWNLOAD_URL_PREFIX = 'https://storage.googleapis.com/golang'
+
+
+class Failure(Exception):
+  """Bootstrap failed."""
+
+
+def get_toolset_url():
+  """URL of a platform specific Go toolset archive."""
+  # TODO(vadimsh): Support toolset for cross-compilation.
+  arch = {
+    'amd64': 'x86-64',
+    'x86_64': 'x86-64',
+    'i386': 'x86-32',
+    'x86': 'x86-32',
+  }.get(platform.machine().lower())
+  variant = TOOLSET_VARIANTS.get((sys.platform, arch))
+  if not variant:
+    # TODO(vadimsh): Compile go lang from source.
+    raise Failure('Unrecognized platform')
+  return '%s/%s.%s' % (DOWNLOAD_URL_PREFIX, TOOLSET_VERSION, variant)
+
+
+def read_file(path):
+  """Returns contents of a given file or None if not readable."""
+  assert isinstance(path, (list, tuple))
+  try:
+    with open(os.path.join(*path), 'r') as f:
+      return f.read()
+  except IOError:
+    return None
+
+
+def write_file(path, data):
+  """Writes |data| to a file."""
+  assert isinstance(path, (list, tuple))
+  with open(os.path.join(*path), 'w') as f:
+    f.write(data)
+
+
+def remove_directory(path):
+  """Recursively removes a directory."""
+  assert isinstance(path, (list, tuple))
+  p = os.path.join(*path)
+  if not os.path.exists(p):
+    return
+  LOGGER.info('Removing %s', p)
+  # Crutch to remove read-only file (.git/* in particular) on Windows.
+  def onerror(func, path, _exc_info):
+    if not os.access(path, os.W_OK):
+      os.chmod(path, stat.S_IWUSR)
+      func(path)
+    else:
+      raise
+  shutil.rmtree(p, onerror=onerror if sys.platform == 'win32' else None)
+
+
+def install_toolset(toolset_root, url):
+  """Downloads and installs Go toolset.
+
+  GOROOT would be <toolset_root>/go/.
+  """
+  if not os.path.exists(toolset_root):
+    os.makedirs(toolset_root)
+  pkg_path = os.path.join(toolset_root, url[url.rfind('/')+1:])
+
+  LOGGER.info('Downloading %s...', url)
+  download_file(url, pkg_path)
+
+  LOGGER.info('Extracting...')
+  if pkg_path.endswith('.zip'):
+    with zipfile.ZipFile(pkg_path, 'r') as f:
+      f.extractall(toolset_root)
+  elif pkg_path.endswith('.tar.gz'):
+    with tarfile.open(pkg_path, 'r:gz') as f:
+      f.extractall(toolset_root)
+  else:
+    raise Failure('Unrecognized archive format')
+
+  LOGGER.info('Validating...')
+  if not check_hello_world(toolset_root):
+    raise Failure('Something is not right, test program doesn\'t work')
+
+
+def download_file(url, path):
+  """Fetches |url| to |path|."""
+  last_progress = [0]
+  def report(a, b, c):
+    progress = int(a * b * 100.0 / c)
+    if progress != last_progress[0]:
+      print >> sys.stderr, 'Downloading... %d%%' % progress
+      last_progress[0] = progress
+  # TODO(vadimsh): Use something less crippled, something that validates SSL.
+  urllib.urlretrieve(url, path, reporthook=report)
+
+
+@contextlib.contextmanager
+def temp_dir(path):
+  """Creates a temporary directory, then deletes it."""
+  tmp = tempfile.mkdtemp(dir=path)
+  try:
+    yield tmp
+  finally:
+    remove_directory([tmp])
+
+
+def check_hello_world(toolset_root):
+  """Compiles and runs 'hello world' program to verify that toolset works."""
+  with temp_dir(toolset_root) as tmp:
+    path = os.path.join(tmp, 'hello.go')
+    write_file([path], r"""
+        package main
+        func main() { println("hello, world\n") }
+    """)
+    out = subprocess.check_output(
+        [get_go_exe(toolset_root), 'run', path],
+        env=get_go_environ(toolset_root, tmp),
+        stderr=subprocess.STDOUT)
+    if out.strip() != 'hello, world':
+      LOGGER.error('Failed to run sample program:\n%s', out)
+      return False
+    return True
+
+
+def ensure_toolset_installed(toolset_root):
+  """Installs or updates Go toolset if necessary.
+
+  Returns True if new toolset was installed.
+  """
+  installed = read_file([toolset_root, 'INSTALLED_TOOLSET'])
+  available = get_toolset_url()
+  if installed == available:
+    LOGGER.debug('Go toolset is up-to-date: %s', TOOLSET_VERSION)
+    return False
+
+  LOGGER.info('Installing Go toolset.')
+  LOGGER.info('  Old toolset is %s', installed)
+  LOGGER.info('  New toolset is %s', available)
+  remove_directory([toolset_root])
+  install_toolset(toolset_root, available)
+  LOGGER.info('Go toolset installed: %s', TOOLSET_VERSION)
+  write_file([toolset_root, 'INSTALLED_TOOLSET'], available)
+  return True
+
+
+def get_go_environ(
+    toolset_root,
+    workspace=None):
+  """Returns a copy of os.environ with added GO* environment variables.
+
+  Overrides GOROOT, GOPATH and GOBIN. Keeps everything else. Idempotent.
+
+  Args:
+    toolset_root: GOROOT would be <toolset_root>/go.
+    workspace: main workspace directory or None if compiling in GOROOT.
+  """
+  env = os.environ.copy()
+  env['GOROOT'] = os.path.join(toolset_root, 'go')
+  if workspace:
+    env['GOBIN'] = os.path.join(workspace, 'bin')
+  else:
+    env.pop('GOBIN', None)
+
+  all_go_paths = []
+  if workspace:
+    all_go_paths.append(workspace)
+  env['GOPATH'] = os.pathsep.join(all_go_paths)
+
+  # New PATH entries.
+  paths_to_add = [
+    os.path.join(env['GOROOT'], 'bin'),
+    env.get('GOBIN'),
+  ]
+
+  # Make sure not to add duplicates entries to PATH over and over again when
+  # get_go_environ is invoked multiple times.
+  path = env['PATH'].split(os.pathsep)
+  paths_to_add = [p for p in paths_to_add if p and p not in path]
+  env['PATH'] = os.pathsep.join(paths_to_add + path)
+
+  return env
+
+
+def get_go_exe(toolset_root):
+  """Returns path to go executable."""
+  return os.path.join(toolset_root, 'go', 'bin', 'go' + EXE_SFX)
+
+
+def bootstrap(logging_level):
+  """Installs all dependencies in default locations.
+
+  Supposed to be called at the beginning of some script (it modifies logger).
+
+  Args:
+    logging_level: logging level of bootstrap process.
+  """
+  logging.basicConfig()
+  LOGGER.setLevel(logging_level)
+  ensure_toolset_installed(TOOLSET_ROOT)
+
+
+def prepare_go_environ():
+  """Returns dict with environment variables to set to use Go toolset.
+
+  Installs or updates the toolset if necessary.
+  """
+  bootstrap(logging.INFO)
+  return get_go_environ(TOOLSET_ROOT, WORKSPACE)
+
+
+def find_executable(name, workspaces):
+  """Returns full path to an executable in some bin/ (in GOROOT or GOBIN)."""
+  basename = name
+  if EXE_SFX and basename.endswith(EXE_SFX):
+    basename = basename[:-len(EXE_SFX)]
+  roots = [os.path.join(TOOLSET_ROOT, 'go', 'bin')]
+  for path in workspaces:
+    roots.extend([
+      os.path.join(path, 'bin'),
+    ])
+  for root in roots:
+    full_path = os.path.join(root, basename + EXE_SFX)
+    if os.path.exists(full_path):
+      return full_path
+  return name
+
+
+def main(args):
+  if args:
+    print >> sys.stderr, sys.modules[__name__].__doc__,
+    return 2
+  bootstrap(logging.DEBUG)
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))