Class HttpPlugin

src/plugins/HttpPlugin.ts:32–224

import { ignoreHttpMethodCheck } from '../config/AgentConfig';

class HttpPlugin implements SwPlugin {
  readonly module = 'http';
  readonly versions = '*';
  readonly isBuiltIn = true;

  install(): void {
    const http = require('http');
    const https = require('https');

    this.interceptClientRequest(http, 'http');
    this.interceptServerRequest(http, 'http');
    this.interceptClientRequest(https, 'https');
    this.interceptServerRequest(https, 'https');
  }

  private interceptClientRequest(module: any, protocol: string) {
    const _request = module.request; // BUG! this doesn't work with "import {request} from http", but haven't found an alternative yet

    module.request = function () {
      const url: URL | string | RequestOptions = arguments[0];

      const { host, pathname } =
        url instanceof URL
          ? url
          : typeof url === 'string'
          ? new URL(url) // TODO: this may throw invalid URL
          : {
              host: (url.host || url.hostname || 'unknown') + ':' + (url.port || 80),
              pathname: url.path || '/',
            };

      const operation = pathname.replace(/\?.*$/g, '');
      const method = arguments[url instanceof URL || typeof url === 'string' ? 1 : 0]?.method || 'GET';
      const span = ignoreHttpMethodCheck(method)
        ? DummySpan.create()
        : ContextManager.current.newExitSpan(operation, Component.HTTP);

      if (span.depth)
        // if we inherited from a higher level plugin then do nothing, higher level should do all the work and we don't duplicate here
        return _request.apply(this, arguments);

      span.start();

      try {
        span.component = Component.HTTP;
        span.layer = SpanLayer.HTTP;
        span.peer = host;

        span.tag(Tag.httpURL(protocol + '://' + host + pathname));
        span.tag(Tag.httpMethod(method));

        const copyStatusAndWrapEmit = (res: any) => {
          span.tag(Tag.httpStatusCode(res.statusCode));

          if (res.statusCode && res.statusCode >= 400) span.errored = true;

          if (res.statusMessage) span.tag(Tag.httpStatusMsg(res.statusMessage));