417 lines
12 KiB
Python
Executable File
417 lines
12 KiB
Python
Executable File
# Copyright 2019 Google LLC
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
"""Wrapper script which makes a network request.
|
|
|
|
Basic Usage: network_request.py post
|
|
--url <url>
|
|
--header <header> (optional, support multiple)
|
|
--body <body> (optional)
|
|
--timeout <secs> (optional)
|
|
--verbose (optional)
|
|
"""
|
|
|
|
import argparse
|
|
import inspect
|
|
import logging
|
|
import socket
|
|
import sys
|
|
|
|
# pylint: disable=g-import-not-at-top
|
|
# pylint: disable=g-importing-member
|
|
try:
|
|
from six.moves.http_client import HTTPSConnection
|
|
from six.moves.http_client import HTTPConnection
|
|
from six.moves.http_client import HTTPException
|
|
except ImportError:
|
|
from http.client import HTTPSConnection
|
|
from http.client import HTTPConnection
|
|
from http.client import HTTPException
|
|
|
|
try:
|
|
from six.moves.urllib.parse import urlparse
|
|
except ImportError:
|
|
from urllib.parse import urlparse
|
|
# pylint: enable=g-import-not-at-top
|
|
# pylint: enable=g-importing-member
|
|
|
|
# Set up logger as soon as possible
|
|
formatter = logging.Formatter('[%(levelname)s] %(message)s')
|
|
|
|
handler = logging.StreamHandler(stream=sys.stdout)
|
|
handler.setFormatter(formatter)
|
|
handler.setLevel(logging.INFO)
|
|
|
|
logger = logging.getLogger(__name__)
|
|
logger.addHandler(handler)
|
|
logger.setLevel(logging.INFO)
|
|
|
|
# Custom exit codes for known issues.
|
|
# System exit codes in python are valid from 0 - 256, so we will map some common
|
|
# ones here to understand successes and failures.
|
|
# Uses lower ints to not collide w/ HTTP status codes that the script may return
|
|
EXIT_CODE_SUCCESS = 0
|
|
EXIT_CODE_SYS_ERROR = 1
|
|
EXIT_CODE_INVALID_REQUEST_VALUES = 2
|
|
EXIT_CODE_GENERIC_HTTPLIB_ERROR = 3
|
|
EXIT_CODE_HTTP_TIMEOUT = 4
|
|
EXIT_CODE_HTTP_REDIRECT_ERROR = 5
|
|
EXIT_CODE_HTTP_NOT_FOUND_ERROR = 6
|
|
EXIT_CODE_HTTP_SERVER_ERROR = 7
|
|
EXIT_CODE_HTTP_UNKNOWN_ERROR = 8
|
|
|
|
MAX_EXIT_CODE = 8
|
|
|
|
# All used http verbs
|
|
POST = 'POST'
|
|
|
|
|
|
def unwrap_kwarg_namespace(func):
|
|
"""Transform a Namespace object from argparse into proper args and kwargs.
|
|
|
|
For a function that will be delegated to from argparse, inspect all of the
|
|
argments and extract them from the Namespace object.
|
|
|
|
Args:
|
|
func: the function that we are wrapping to modify behavior
|
|
|
|
Returns:
|
|
a new function that unwraps all of the arguments in a namespace and then
|
|
delegates to the passed function with those args.
|
|
"""
|
|
# When we move to python 3, getfullargspec so that we can tell the
|
|
# difference between args and kwargs -- then this could be used for functions
|
|
# that have both args and kwargs
|
|
if 'getfullargspec' in dir(inspect):
|
|
argspec = inspect.getfullargspec(func)
|
|
else:
|
|
argspec = inspect.getargspec(func) # Python 2 compatibility.
|
|
|
|
def wrapped(argparse_namespace=None, **kwargs):
|
|
"""Take a Namespace object and map it to kwargs.
|
|
|
|
Inspect the argspec of the passed function. Loop over all the args that
|
|
are present in the function and try to map them by name to arguments in the
|
|
namespace. For keyword arguments, we do not require that they be present
|
|
in the Namespace.
|
|
|
|
Args:
|
|
argparse_namespace: an arparse.Namespace object, the result of calling
|
|
argparse.ArgumentParser().parse_args()
|
|
**kwargs: keyword arguments that may be passed to the original function
|
|
Returns:
|
|
The return of the wrapped function from the parent.
|
|
|
|
Raises:
|
|
ValueError in the event that an argument is passed to the cli that is not
|
|
in the set of named kwargs
|
|
"""
|
|
if not argparse_namespace:
|
|
return func(**kwargs)
|
|
|
|
reserved_namespace_keywords = ['func']
|
|
new_kwargs = {}
|
|
|
|
args = argspec.args or []
|
|
for arg_name in args:
|
|
passed_value = getattr(argparse_namespace, arg_name, None)
|
|
if passed_value is not None:
|
|
new_kwargs[arg_name] = passed_value
|
|
|
|
for namespace_key in vars(argparse_namespace).keys():
|
|
# ignore namespace keywords that have been set not passed in via cli
|
|
if namespace_key in reserved_namespace_keywords:
|
|
continue
|
|
|
|
# make sure that we haven't passed something we should be processing
|
|
if namespace_key not in args:
|
|
raise ValueError('CLI argument "{}" does not match any argument in '
|
|
'function {}'.format(namespace_key, func.__name__))
|
|
|
|
return func(**new_kwargs)
|
|
|
|
wrapped.__name__ = func.__name__
|
|
return wrapped
|
|
|
|
|
|
class NetworkRequest(object):
|
|
"""A container for an network request object.
|
|
|
|
This class holds on to all of the attributes necessary for making a
|
|
network request via httplib.
|
|
"""
|
|
|
|
def __init__(self, url, method, headers, body, timeout):
|
|
self.url = url.lower()
|
|
self.parsed_url = urlparse(self.url)
|
|
self.method = method
|
|
self.headers = headers
|
|
self.body = body
|
|
self.timeout = timeout
|
|
self.is_secure_connection = self.is_secure_connection()
|
|
|
|
def execute_request(self):
|
|
""""Execute the request, and get a response.
|
|
|
|
Returns:
|
|
an HttpResponse object from httplib
|
|
"""
|
|
if self.is_secure_connection:
|
|
conn = HTTPSConnection(self.get_hostname(), timeout=self.timeout)
|
|
else:
|
|
conn = HTTPConnection(self.get_hostname(), timeout=self.timeout)
|
|
|
|
conn.request(self.method, self.url, self.body, self.headers)
|
|
response = conn.getresponse()
|
|
return response
|
|
|
|
def get_hostname(self):
|
|
"""Return the hostname for the url."""
|
|
return self.parsed_url.netloc
|
|
|
|
def is_secure_connection(self):
|
|
"""Checks for a secure connection of https.
|
|
|
|
Returns:
|
|
True if the scheme is "https"; False if "http"
|
|
|
|
Raises:
|
|
ValueError when the scheme does not match http or https
|
|
"""
|
|
scheme = self.parsed_url.scheme
|
|
|
|
if scheme == 'http':
|
|
return False
|
|
elif scheme == 'https':
|
|
return True
|
|
else:
|
|
raise ValueError('The url scheme is not "http" nor "https"'
|
|
': {}'.format(scheme))
|
|
|
|
|
|
def parse_colon_delimited_options(option_args):
|
|
"""Parses a key value from a string.
|
|
|
|
Args:
|
|
option_args: Key value string delimited by a color, ex: ("key:value")
|
|
|
|
Returns:
|
|
Return an array with the key as the first element and value as the second
|
|
|
|
Raises:
|
|
ValueError: If the key value option is not formatted correctly
|
|
"""
|
|
options = {}
|
|
|
|
if not option_args:
|
|
return options
|
|
|
|
for single_arg in option_args:
|
|
values = single_arg.split(':')
|
|
if len(values) != 2:
|
|
raise ValueError('An option arg must be a single key/value pair '
|
|
'delimited by a colon - ex: "thing_key:thing_value"')
|
|
|
|
key = values[0].strip()
|
|
value = values[1].strip()
|
|
options[key] = value
|
|
|
|
return options
|
|
|
|
|
|
def make_request(request):
|
|
"""Makes a synchronous network request and return the HTTP status code.
|
|
|
|
Args:
|
|
request: a well formulated request object
|
|
|
|
Returns:
|
|
The HTTP status code of the network request.
|
|
'1' maps to invalid request headers.
|
|
"""
|
|
|
|
logger.info('Sending network request -')
|
|
logger.info('\tUrl: %s', request.url)
|
|
logger.debug('\tMethod: %s', request.method)
|
|
logger.debug('\tHeaders: %s', request.headers)
|
|
logger.debug('\tBody: %s', request.body)
|
|
|
|
try:
|
|
response = request.execute_request()
|
|
except socket.timeout:
|
|
logger.exception(
|
|
'Timed out post request to %s in %d seconds for request body: %s',
|
|
request.url, request.timeout, request.body)
|
|
return EXIT_CODE_HTTP_TIMEOUT
|
|
except (HTTPException, socket.error):
|
|
logger.exception(
|
|
'Encountered generic exception in posting to %s with request body %s',
|
|
request.url, request.body)
|
|
return EXIT_CODE_GENERIC_HTTPLIB_ERROR
|
|
|
|
status = response.status
|
|
headers = response.getheaders()
|
|
logger.info('Received Network response -')
|
|
logger.info('\tStatus code: %d', status)
|
|
logger.debug('\tResponse headers: %s', headers)
|
|
|
|
if status < 200 or status > 299:
|
|
logger.error('Request (%s) failed with status code %d\n', request.url,
|
|
status)
|
|
|
|
# If we wanted this script to support get, we need to
|
|
# figure out what mechanism we intend for capturing the response
|
|
return status
|
|
|
|
|
|
@unwrap_kwarg_namespace
|
|
def post(url=None, header=None, body=None, timeout=5, verbose=False):
|
|
"""Sends a post request.
|
|
|
|
Args:
|
|
url: The url of the request
|
|
header: A list of headers for the request
|
|
body: The body for the request
|
|
timeout: Timeout in seconds for the request
|
|
verbose: Should debug logs be displayed
|
|
|
|
Returns:
|
|
Return an array with the key as the first element and value as the second
|
|
"""
|
|
|
|
if verbose:
|
|
handler.setLevel(logging.DEBUG)
|
|
logger.setLevel(logging.DEBUG)
|
|
|
|
try:
|
|
logger.info('Parsing headers: %s', header)
|
|
headers = parse_colon_delimited_options(header)
|
|
except ValueError:
|
|
logging.exception('Could not parse the parameters with "--header": %s',
|
|
header)
|
|
return EXIT_CODE_INVALID_REQUEST_VALUES
|
|
|
|
try:
|
|
request = NetworkRequest(url, POST, headers, body, float(timeout))
|
|
except ValueError:
|
|
logger.exception('Invalid request values passed into the script.')
|
|
return EXIT_CODE_INVALID_REQUEST_VALUES
|
|
|
|
status = make_request(request)
|
|
|
|
# View exit code after running to get the http status code: 'echo $?'
|
|
return status
|
|
|
|
|
|
def get_argsparser():
|
|
"""Returns the argument parser.
|
|
|
|
Returns:
|
|
Argument parser for the script.
|
|
"""
|
|
|
|
parser = argparse.ArgumentParser(
|
|
description='The script takes in the arguments of a network request. '
|
|
'The network request is sent and the http status code will be'
|
|
'returned as the exit code.')
|
|
subparsers = parser.add_subparsers(help='Commands:')
|
|
post_parser = subparsers.add_parser(
|
|
post.__name__, help='{} help'.format(post.__name__))
|
|
post_parser.add_argument(
|
|
'--url',
|
|
help='Request url. Ex: https://www.google.com/somePath/',
|
|
required=True,
|
|
dest='url')
|
|
post_parser.add_argument(
|
|
'--header',
|
|
help='Request headers as a space delimited list of key '
|
|
'value pairs. Ex: "key1:value1 key2:value2"',
|
|
action='append',
|
|
required=False,
|
|
dest='header')
|
|
post_parser.add_argument(
|
|
'--body',
|
|
help='The body of the network request',
|
|
required=True,
|
|
dest='body')
|
|
post_parser.add_argument(
|
|
'--timeout',
|
|
help='The timeout in seconds',
|
|
default=10.0,
|
|
required=False,
|
|
dest='timeout')
|
|
post_parser.add_argument(
|
|
'--verbose',
|
|
help='Should verbose logging be outputted',
|
|
action='store_true',
|
|
default=False,
|
|
required=False,
|
|
dest='verbose')
|
|
post_parser.set_defaults(func=post)
|
|
return parser
|
|
|
|
|
|
def map_http_status_to_exit_code(status_code):
|
|
"""Map an http status code to the appropriate exit code.
|
|
|
|
Exit codes in python are valid from 0-256, so we want to map these to
|
|
predictable exit codes within range.
|
|
|
|
Args:
|
|
status_code: the input status code that was output from the network call
|
|
function
|
|
|
|
Returns:
|
|
One of our valid exit codes declared at the top of the file or a generic
|
|
unknown error code
|
|
"""
|
|
if status_code <= MAX_EXIT_CODE:
|
|
return status_code
|
|
|
|
if status_code > 199 and status_code < 300:
|
|
return EXIT_CODE_SUCCESS
|
|
|
|
if status_code == 302:
|
|
return EXIT_CODE_HTTP_REDIRECT_ERROR
|
|
|
|
if status_code == 404:
|
|
return EXIT_CODE_HTTP_NOT_FOUND_ERROR
|
|
|
|
if status_code > 499:
|
|
return EXIT_CODE_HTTP_SERVER_ERROR
|
|
|
|
return EXIT_CODE_HTTP_UNKNOWN_ERROR
|
|
|
|
|
|
def main():
|
|
"""Main function to run the program.
|
|
|
|
Parse system arguments and delegate to the appropriate function.
|
|
|
|
Returns:
|
|
A status code - either an http status code or a custom error code
|
|
"""
|
|
parser = get_argsparser()
|
|
subparser_action = parser.parse_args()
|
|
try:
|
|
return subparser_action.func(subparser_action)
|
|
except ValueError:
|
|
logger.exception('Invalid arguments passed.')
|
|
parser.print_help(sys.stderr)
|
|
return EXIT_CODE_INVALID_REQUEST_VALUES
|
|
return EXIT_CODE_GENERIC_HTTPLIB_ERROR
|
|
|
|
if __name__ == '__main__':
|
|
exit_code = map_http_status_to_exit_code(main())
|
|
sys.exit(exit_code)
|