| /*! |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| * |
| */ |
| |
| import SwPlugin from '../core/SwPlugin'; |
| import { IncomingMessage, ServerResponse } from 'http'; |
| import ContextManager from '../trace/context/ContextManager'; |
| import { Component } from '../trace/Component'; |
| import Tag from '../Tag'; |
| import { SpanLayer } from '../proto/language-agent/Tracing_pb'; |
| import { ContextCarrier } from '../trace/context/ContextCarrier'; |
| import onFinished from 'on-finished'; |
| |
| class ExpressPlugin implements SwPlugin { |
| readonly module = 'express'; |
| readonly versions = '*'; |
| |
| install(): void { |
| this.interceptServerRequest(); |
| } |
| |
| private interceptServerRequest() { |
| const router = require('express/lib/router'); |
| const _handle = router.handle; |
| |
| router.handle = function(req: IncomingMessage, res: ServerResponse, out: any) { |
| const headers = req.rawHeaders || []; |
| const headersMap: { [key: string]: string } = {}; |
| |
| for (let i = 0; i < headers.length / 2; i += 2) { |
| headersMap[headers[i]] = headers[i + 1]; |
| } |
| |
| const carrier = ContextCarrier.from(headersMap); |
| const operation = (req.url || '/').replace(/\?.*/g, ''); |
| const span = ContextManager.current.newEntrySpan(operation, carrier).start(); |
| |
| let stopped = 0; |
| const stopIfNotStopped = (err: Error | null) => { |
| if (!stopped++) { |
| span.stop(); |
| span.tag(Tag.httpStatusCode(res.statusCode)); |
| if (res.statusCode && res.statusCode >= 400) { |
| span.errored = true; |
| } |
| if (err) { |
| span.error(err); |
| } |
| if (res.statusMessage) { |
| span.tag(Tag.httpStatusMsg(res.statusMessage)); |
| } |
| } |
| }; |
| |
| try { |
| span.layer = SpanLayer.HTTP; |
| span.component = Component.EXPRESS; |
| span.peer = req.headers.host || ''; |
| span.tag(Tag.httpURL(span.peer + req.url)); |
| |
| const ret = _handle.call(this, req, res, (err: Error) => { |
| if (err) { |
| span.error(err); |
| } else { |
| span.errored = true; |
| } |
| out.call(this, err); |
| stopped -= 1; // skip first stop attempt, make sure stop executes once status code and message is set |
| }); |
| onFinished(res, stopIfNotStopped); // this must run after any handlers deferred in 'out' |
| |
| return ret; |
| } catch (e) { |
| stopIfNotStopped(e); |
| throw e; |
| } |
| }; |
| } |
| } |
| |
| // noinspection JSUnusedGlobalSymbols |
| export default new ExpressPlugin(); |