src/plugins/AxiosPlugin.ts

/*!
 *
 * 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 { URL } from 'url';
import ContextManager from '../trace/context/ContextManager';
import { Component } from '../trace/Component';
import Tag from '../Tag';
import { SpanLayer } from '../proto/language-agent/Tracing_pb';
import DummySpan from '../trace/span/DummySpan';
import { ignoreHttpMethodCheck } from '../config/AgentConfig';
import PluginInstaller from '../core/PluginInstaller';

class AxiosPlugin implements SwPlugin {
  readonly module = 'axios';
  readonly versions = '*';

  install(installer: PluginInstaller): void {
    this.interceptClientRequest(installer);
  }

  private interceptClientRequest(installer: PluginInstaller): void {
    const Axios = installer.require('axios/lib/core/Axios');
    const _request = Axios.prototype.request;

    Axios.prototype.request = function(url?: any, config?: any) {
      if (typeof url === 'string')
        config = config ? {...config, url} : {url};
      else
        config = url ? {...url} : {};

      const {origin, host, pathname: operation} = new URL(config.url);  // TODO: this may throw invalid URL
      const method = (config.method || 'GET').toUpperCase();
      const span = ignoreHttpMethodCheck(method)
        ? DummySpan.create()
        : ContextManager.current.newExitSpan(operation, host, Component.AXIOS, Component.HTTP);

      span.start();

      try {
        config.headers = config.headers ? {...config.headers} : {};

        span.component = Component.AXIOS;
        span.layer = SpanLayer.HTTP;
        span.peer = host;

        span.tag(Tag.httpURL(origin + operation));
        span.tag(Tag.httpMethod(method));

        span.inject().items.forEach((item) => config.headers[item.key] = item.value);

        const copyStatus = (response: any) => {
          if (response) {
            if (response.status) {
              span.tag(Tag.httpStatusCode(response.status));

              if (response.status >= 400)
                span.errored = true;
            }

            if (response.statusText)
              span.tag(Tag.httpStatusMsg(response.statusText));
          }
        };

        const ret = _request.call(this, config).then(
          (res: any) => {
            copyStatus(res);
            span.stop();

            return res;
          },

          (err: any) => {
            copyStatus(err.response);
            span.error(err);
            span.stop();

            return Promise.reject(err);
          }
        );

        span.async();

        return ret;

      } catch (err) {
        span.error(err);
        span.stop();

        throw err;
      }
    };
  }
}

// noinspection JSUnusedGlobalSymbols
export default new AxiosPlugin();