Add URL recipe module from "depot_tools".

recipe_modules/url/resources/pycurl.py

Index: recipe_modules/url/resources/pycurl.py
diff --git a/recipe_modules/url/resources/pycurl.py b/recipe_modules/url/resources/pycurl.py
new file mode 100644
index 0000000000000000000000000000000000000000..0f9f519d5aa54d8708261c750f5481f88b5a9d1b
--- /dev/null
+++ b/recipe_modules/url/resources/pycurl.py
@@ -0,0 +1,222 @@
+#!/usr/bin/env python
+# Copyright 2017 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.
+
+# NOTE: This was imported from Chromium's "tools/build" at revision:
+# 65976b6e2a612439681dc42830e90dbcdf550f40
+
+import argparse
+import json
+import logging
+import os
+import sys
+import time
+
+import requests
+import requests.adapters
+import requests.exceptions
+import requests.models
+from requests.packages.urllib3.util.retry import Retry
+
+
+# Size of chunks (4MiB).
+CHUNK_SIZE = 1024 * 1024 * 4
+
+
+def _download(url, outfile, headers, transient_retry, strip_prefix):
+  s = requests.Session()
+  retry = None
+  if transient_retry > 0:
+    # See http://urllib3.readthedocs.io/en/latest/reference/urllib3.util.html
+    retry = Retry(
+      total=transient_retry,
+      connect=5,
+      read=5,
+      redirect=5,
+      status_forcelist=range(500, 600),
+      backoff_factor=0.2,
+      raise_on_status=False,
+    )
+    print retry
+    s.mount(url, requests.adapters.HTTPAdapter(max_retries=retry))
+
+
+  logging.info('Connecting to %s ...', url)
+  r = s.get(url, headers=headers, stream=True)
+  if r.status_code != requests.codes.ok:
+    r.raise_for_status()
+
+  if outfile:
+    fd = open(outfile, 'wb')
+  else:
+    fd = sys.stdout
+
+  total = 0
+  with fd:
+    logging.info('Downloading %s ...', url)
+    loaded_prefix = ''
+    for chunk in r.iter_content(CHUNK_SIZE):
+      total += len(chunk)
+
+      if strip_prefix:
+        remaining_prefix = strip_prefix[len(loaded_prefix):]
+        round_prefix = chunk[:len(remaining_prefix)]
+        loaded_prefix += round_prefix
+        if round_prefix != remaining_prefix[:len(round_prefix)]:
+          raise ValueError(
+              'Expected prefix was not observed: %r != %r...' % (
+              loaded_prefix, strip_prefix))
+        chunk = chunk[len(loaded_prefix):]
+        if not chunk:
+          continue
+
+      fd.write(chunk)
+      logging.info('Downloaded %.1f MB so far', total / 1024 / 1024)
+  return r.status_code, total
+
+
+def main():
+  parser = argparse.ArgumentParser(
+      description='Get a url and print its document.',
+      prog='./runit.py pycurl.py')
+  parser.add_argument('--url', required=True, help='the url to fetch')
+  parser.add_argument('--status-json', metavar='PATH', required=True,
+      help='Write HTTP status result JSON. If set, all complete HTTP '
+           'responses will exit with 0, regardless of their status code.')
+
+  parser.add_argument('--transient-retry', type=int, default=10,
+      help='Number of retry attempts (with exponential backoff) to make on '
+           'transient failure (default is %(default)s).')
+  parser.add_argument('--headers-json', type=argparse.FileType('r'),
+      help='A json file containing any headers to include with the request.')
+  parser.add_argument('--outfile', help='write output to this file')
+  parser.add_argument('--strip-prefix', action='store', type=json.loads,
+      help='Expect this string at the beginning of the response, and strip it.')
+
+  args = parser.parse_args()
+
+  headers = None
+  if args.headers_json:
+    headers = json.load(args.headers_json)
+
+  if args.strip_prefix and len(args.strip_prefix) > CHUNK_SIZE:
+    raise ValueError('Prefix length (%d) must be <= chunk size (%d)' % (
+        len(args.strip_prefix), CHUNK_SIZE))
+
+  status = {}
+  try:
+    status_code, size = _download(
+        args.url, args.outfile, headers, args.transient_retry,
+        args.strip_prefix)
+    status = {
+      'status_code': status_code,
+      'success': True,
+      'size': size,
+    }
+  except requests.HTTPError as e:
+    body = e.response.text
+    status = {
+      'status_code': e.response.status_code,
+      'success': False,
+      'size': len(body),
+      'error_body': body,
+    }
+
+  with open(args.status_json, 'w') as fd:
+    json.dump(status, fd)
+  return 0
+
+
+if __name__ == '__main__':
+  logging.basicConfig()
+  logging.getLogger().setLevel(logging.INFO)
+  logging.getLogger("requests").setLevel(logging.DEBUG)
+  sys.exit(main())
+
+
+##
+# The following section is read by "vpython" and used to construct the
+# VirtualEnv for this tool.
+#
+# These imports were lifted from "/bootstrap/venv.cfg".
+##
+# [VPYTHON:BEGIN]
+#
+# wheel: <
+#   name: "infra/python/wheels/cryptography/${platform}_${py_version}_${py_abi}"
+#   version: "version:1.8.1"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/appdirs-py2_py3"
+#   version: "version:1.4.3"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/asn1crypto-py2_py3"
+#   version: "version:0.22.0"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/enum34-py2"
+#   version: "version:1.1.6"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/cffi/${platform}_${py_version}_${py_abi}"
+#   version: "version:1.10.0"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/idna-py2_py3"
+#   version: "version:2.5"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/ipaddress-py2"
+#   version: "version:1.0.18"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/packaging-py2_py3"
+#   version: "version:16.8"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/pyasn1-py2_py3"
+#   version: "version:0.2.3"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/pycparser-py2_py3"
+#   version: "version:2.17"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/pyopenssl-py2_py3"
+#   version: "version:17.0.0"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/pyparsing-py2_py3"
+#   version: "version:2.2.0"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/setuptools-py2_py3"
+#   version: "version:34.3.2"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/six-py2_py3"
+#   version: "version:1.10.0"
+# >
+#
+# wheel: <
+#   name: "infra/python/wheels/requests-py2_py3"
+#   version: "version:2.13.0"
+# >
+#
+# [VPYTHON:END]
+##