gsw945 · August 11, 2018 10:37
diff --git a/flask_reverse_proxy2other_server.py b/flask_reverse_proxy2other_server.py
 import logging
 try:
    from urllib.parse import (
        urlencode,
        parse_qs,
        urlsplit,
        urlunsplit
    )
 except ImportError:
    from urllib import urlencode
    from urlparse import (
        parse_qs,
        urlsplit,
        urlunsplit
    )

 from flask import Flask
 from flask import (
    request,
    Response,
    make_response,
    abort
 )
 from flask.logging import default_handler

 import requests


 # http://flask.pocoo.org/docs/dev/logging/
 class RequestFormatter(logging.Formatter):
    def format(self, record):
        record.url = request.url
        record.remote_addr = request.remote_addr
        return super().format(record)

 formatter = RequestFormatter(
    '[%(asctime)s] %(remote_addr)s requested %(url)s\n'
    '%(levelname)s in %(module)s: %(message)s'
 )
 default_handler.setFormatter(formatter)
 # https://docs.python.org/3/library/logging.html#logging-levels
 # NOTSET->DEBUG->INFO->WARNING->ERROR->CRITICAL
 default_handler.setLevel(logging.NOTSET)
 # root = logging.getLogger()
 # root.addHandler(default_handler)

 def set_query_parameter(url, param_name, param_value):
    """
    Given a URL, set or replace a query parameter and return the modified URL.
    >>> set_query_parameter('http://example.com?foo=bar&biz=baz', 'foo', 'stuff')
    'http://example.com?foo=stuff&biz=baz'
    """
    # from: https://stackoverflow.com/questions/4293460/how-to-add-custom-parameters-to-an-url-query-string-with-python#12897375
    scheme, netloc, path, query_string, fragment = urlsplit(url)
    query_params = parse_qs(query_string)

    query_params[param_name] = [param_value]
    new_query_string = urlencode(query_params, doseq=True)

    return urlunsplit((scheme, netloc, path, new_query_string, fragment))

 def set_domain(url, new_domain, new_scheme=None):
    scheme, netloc, path, query_string, fragment = urlsplit(url)
    if bool(new_scheme):
        scheme = new_scheme
    return urlunsplit((scheme, new_domain, path, query_string, fragment))

 def get_domain(url):
    scheme, netloc, path, query_string, fragment = urlsplit(url)
    return netloc

 # https://stackoverflow.com/questions/6656363/proxying-to-another-web-service-with-flask/36601467#36601467
 def reverse_proxy(old_domain=None, new_domain=None, scheme=None, timeout=10):
    '''reverse-proxy-with'''
    req_url = request.url
    need_set = True
    if bool(old_domain):
        if get_domain(req_url) != old_domain:
            need_set = False
    if need_set:
        req_url = set_domain(req_url, new_domain, scheme)
    req_headers = {key: value for (key, value) in request.headers if key != 'Host'}
    resp = None
    try:
        resp = requests.request(
            method=request.method,
            url=req_url,
            headers=req_headers,
            data=request.get_data(),
            cookies=request.cookies,
            allow_redirects=False,
            timeout=timeout,
            verify=False
        )
    except requests.exceptions.ConnectTimeout:
        return abort(502)
    except requests.exceptions.ConnectionError:
        return abort(503)
    except requests.exceptions.ReadTimeout:
        return abort(504)
    except Exception:
        return abort(500)
    excluded_headers = [
        'content-encoding', 'content-length', 'transfer-encoding', 'connection'
    ]
    headers = [
        (name, value) for (name, value) in resp.raw.headers.items()
        if name.lower() not in excluded_headers
    ]
    response = Response(resp.content, resp.status_code, headers)
    return response


 app = Flask(__name__)


 @app.before_request
 def intercept_hook():
    '''截获'''
    username = request.values.get('username', None)
    if bool(username):
        # TODO: capture request data
        print('窃取到了[username]:', username)
    else:
        if request.method.lower() == 'put':
            return abort(409)
        # return abort(400)
        msgs = [
            '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">',
            '<title>400 Bad Request</title>',
            '<h1>Bad Request</h1>',
            '<p>The browser (or proxy) sent a request that this server could not understand.</p>',
            '<hr />',
            '<h3>{0}</h3>'.format('[username] is required')
        ]
        resp = make_response('\n'.join(msgs))
        return (resp, 400)

 @app.after_request
 def tamper_hook(response):
    '''篡改'''
    response.headers['X-Tamper'] = 'modified'
    return response

 @app.teardown_request
 def cleanup_request(exception):
    '''清理'''
    pass

 @app.route('/', methods=['GET', 'POST'])
 @app.route('/index', methods=['GET', 'POST'])
 def view_index():
    # return 'hello index'
    return reverse_proxy(new_domain='127.0.0.1:5001')

 def main():
    cfg = {
        'host': '0.0.0.0',
        'port': 5656,
        'debug': False
    }
    print('visit via [http://{host}:{port}/]'.format(host='127.0.0.1', port=cfg['port']))
    if not (app.debug or cfg['debug']):
        app.logger.addHandler(default_handler)
    app.run(**cfg)

 if __name__ == '__main__':
    main()
diff --git a/temp-another-server.py b/temp-another-server.py
 from flask import Flask, abort
 import time

 app = Flask(__name__)

 @app.route('/')
 @app.route('/index')
 def viw_idx():
    # time.sleep(31) # simulate timeout, lead ReadTime error
    # return abort(500) # simulate upstream error response
    return 'this is upstream response'
 if __name__ == '__main__':
    app.run(port=5001)
	import logging
	try:
	from urllib.parse import (
	urlencode,
	parse_qs,
	urlsplit,
	urlunsplit
	)
	except ImportError:
	from urllib import urlencode
	from urlparse import (
	parse_qs,
	urlsplit,
	urlunsplit
	)

	from flask import Flask
	from flask import (
	request,
	Response,
	make_response,
	abort
	)
	from flask.logging import default_handler

	import requests


	# http://flask.pocoo.org/docs/dev/logging/
	class RequestFormatter(logging.Formatter):
	def format(self, record):
	record.url = request.url
	record.remote_addr = request.remote_addr
	return super().format(record)

	formatter = RequestFormatter(
	'[%(asctime)s] %(remote_addr)s requested %(url)s\n'
	'%(levelname)s in %(module)s: %(message)s'
	)
	default_handler.setFormatter(formatter)
	# https://docs.python.org/3/library/logging.html#logging-levels
	# NOTSET->DEBUG->INFO->WARNING->ERROR->CRITICAL
	default_handler.setLevel(logging.NOTSET)
	# root = logging.getLogger()
	# root.addHandler(default_handler)

	def set_query_parameter(url, param_name, param_value):
	"""
	Given a URL, set or replace a query parameter and return the modified URL.
	>>> set_query_parameter('http://example.com?foo=bar&biz=baz', 'foo', 'stuff')
	'http://example.com?foo=stuff&biz=baz'
	"""
	# from: https://stackoverflow.com/questions/4293460/how-to-add-custom-parameters-to-an-url-query-string-with-python#12897375
	scheme, netloc, path, query_string, fragment = urlsplit(url)
	query_params = parse_qs(query_string)

	query_params[param_name] = [param_value]
	new_query_string = urlencode(query_params, doseq=True)

	return urlunsplit((scheme, netloc, path, new_query_string, fragment))

	def set_domain(url, new_domain, new_scheme=None):
	scheme, netloc, path, query_string, fragment = urlsplit(url)
	if bool(new_scheme):
	scheme = new_scheme
	return urlunsplit((scheme, new_domain, path, query_string, fragment))

	def get_domain(url):
	scheme, netloc, path, query_string, fragment = urlsplit(url)
	return netloc

	# https://stackoverflow.com/questions/6656363/proxying-to-another-web-service-with-flask/36601467#36601467
	def reverse_proxy(old_domain=None, new_domain=None, scheme=None, timeout=10):
	'''reverse-proxy-with'''
	req_url = request.url
	need_set = True
	if bool(old_domain):
	if get_domain(req_url) != old_domain:
	need_set = False
	if need_set:
	req_url = set_domain(req_url, new_domain, scheme)
	req_headers = {key: value for (key, value) in request.headers if key != 'Host'}
	resp = None
	try:
	resp = requests.request(
	method=request.method,
	url=req_url,
	headers=req_headers,
	data=request.get_data(),
	cookies=request.cookies,
	allow_redirects=False,
	timeout=timeout,
	verify=False
	)
	except requests.exceptions.ConnectTimeout:
	return abort(502)
	except requests.exceptions.ConnectionError:
	return abort(503)
	except requests.exceptions.ReadTimeout:
	return abort(504)
	except Exception:
	return abort(500)
	excluded_headers = [
	'content-encoding', 'content-length', 'transfer-encoding', 'connection'
	]
	headers = [
	(name, value) for (name, value) in resp.raw.headers.items()
	if name.lower() not in excluded_headers
	]
	response = Response(resp.content, resp.status_code, headers)
	return response


	app = Flask(__name__)


	@app.before_request
	def intercept_hook():
	'''截获'''
	username = request.values.get('username', None)
	if bool(username):
	# TODO: capture request data
	print('窃取到了[username]:', username)
	else:
	if request.method.lower() == 'put':
	return abort(409)
	# return abort(400)
	msgs = [
	'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">',
	'<title>400 Bad Request</title>',
	'<h1>Bad Request</h1>',
	'<p>The browser (or proxy) sent a request that this server could not understand.</p>',
	'<hr />',
	'<h3>{0}</h3>'.format('[username] is required')
	]
	resp = make_response('\n'.join(msgs))
	return (resp, 400)

	@app.after_request
	def tamper_hook(response):
	'''篡改'''
	response.headers['X-Tamper'] = 'modified'
	return response

	@app.teardown_request
	def cleanup_request(exception):
	'''清理'''
	pass

	@app.route('/', methods=['GET', 'POST'])
	@app.route('/index', methods=['GET', 'POST'])
	def view_index():
	# return 'hello index'
	return reverse_proxy(new_domain='127.0.0.1:5001')

	def main():
	cfg = {
	'host': '0.0.0.0',
	'port': 5656,
	'debug': False
	}
	print('visit via [http://{host}:{port}/]'.format(host='127.0.0.1', port=cfg['port']))
	if not (app.debug or cfg['debug']):
	app.logger.addHandler(default_handler)
	app.run(**cfg)

	if __name__ == '__main__':
	main()
	from flask import Flask, abort
	import time

	app = Flask(__name__)

	@app.route('/')
	@app.route('/index')
	def viw_idx():
	# time.sleep(31) # simulate timeout, lead ReadTime error
	# return abort(500) # simulate upstream error response
	return 'this is upstream response'
	if __name__ == '__main__':
	app.run(port=5001)