149 lines
5.3 KiB
Python
149 lines
5.3 KiB
Python
import requests
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import utils
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import json
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import logging as logger
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#import InvalidParameterException
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from flask import make_response
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from flask import request
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from ExceptionHandler import *
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class NoopExceptionHandler(ExceptionHandler):
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DEFAULT_CONTENT = {
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"error_code": "InternalServerError",
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"error_message": "",
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"error_message_chs": "服务器内部错误"
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}
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def handle(self, e, *args, **kwargs):
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logger.exception("Unknown exception occurred: %s", e)
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content = dict(self.DEFAULT_CONTENT)
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content['error_message'] = e.message
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return json.dumps(content), 500
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class GenericGateway(object):
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def __init__(self, app, routes, url_supplier, exception_handler=None):
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"""
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:param app: flask app
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:type app: flask.Flask
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:param routes: 路由列表
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:type routes: list of Route
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:param url_supplier: 服务名称解析函数，通过service name获取service url: url_supplier(service_name) -> service_url
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:type url_supplier: function
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:param exception_handler: exception handle decorator
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:type exception_handler: ExceptionHandler
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"""
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if not callable(url_supplier):
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raise ValueError("service url supplier (url_supplier) must be callable")
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self.app = app
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self.routes = routes
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self.url_supplier = url_supplier
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self.exception_handler = exception_handler or NoopExceptionHandler()
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self.proxy_list = []
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def get_url(self, service_name):
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try:
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return self.url_supplier(service_name)
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except Exception as e:
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logger.warning("Failed to get the url of service: %s", service_name, exc_info=True)
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raise RuntimeError("Failed to get the url of service {}: {}".format(service_name, e))
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def create_request_proxy(self, route):
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logger.info("Register route: %s", route.path)
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def proxy_request(*args, **kwargs):
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upstream_path = route.upstream_path
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for p_name in route.upstream_params:
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v = get_params_from_context(p_name, kwargs)
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upstream_path = utils.replace_placeholder(upstream_path, p_name, v)
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endpoint = self.get_url(route.service_name)
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final_url = "{}{}".format(endpoint, upstream_path)
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upstream_req_info = dict(
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url=final_url,
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method=request.method,
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params=request.args,
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data=request.data,
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files=request.files,
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headers=request.headers,
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)
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if request.form:
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upstream_req_info['data'] = request.form
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for pipe_handler in route.inbound_pipes():
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upstream_req_info, args, kwargs = pipe_handler(upstream_req_info, *args, **kwargs)
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content_type = upstream_req_info['headers'].get('Content-Type')
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if content_type and 'boundary' in content_type:
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# requests prepare body时，会使重新生成 boundary，headers中旧的 boundary 会导致上游服务无法识别
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upstream_req_info['headers'] = {k: v for k, v in upstream_req_info['headers'].items()}
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upstream_req_info['headers'].pop('Content-Type', None)
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upstream_req_info['headers'].pop('content-type', None)
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resp = requests.request(**upstream_req_info)
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status = resp.status_code
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content = None
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headers = resp.headers
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for pipe_handler in route.outbound_pipes():
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resp, headers, status, content = pipe_handler(resp, headers, status, content, *args, **kwargs)
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content = make_response(content or resp.content)
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for h_name, h_value in (headers or {}).items():
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content.headers[h_name] = h_value
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return content, status
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# 修改函数名称：Flask route注册使用func name必须唯一
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proxy_request.__name__ = route.name
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return proxy_request
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def _register_route(self, route):
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"""
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:param Route route:
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"""
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proxy = self.create_request_proxy(route)
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self.proxy_list.append(
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self.app.route(route.path, methods=route.methods)(proxy)
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)
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def register_routes(self):
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for route in self.routes:
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self._register_route(route)
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def get_params_from_context(param_name, kwargs):
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"""按顺序尝试从url参数、headers、args、form、json中获取参数值
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"""
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payload = {}
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if kwargs and kwargs.get(param_name):
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payload = kwargs
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elif request.headers.get(param_name):
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payload = request.headers
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elif request.args and request.args.get(param_name):
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payload = request.args
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elif request.form and request.form.get(param_name):
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payload = request.form
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elif request.data:
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body = json.loads(request.data)
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if body and body.get(param_name):
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payload = body
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try:
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return payload[param_name]
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except KeyError as e:
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# raise InvalidParameterException(
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# message="Missing the required params: {}".format(e),
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# message_chs="缺少必要的参数 {}".format(e)
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# )
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print('') |