Index: node_modules/agentkeepalive/lib/agent.js
===================================================================
--- node_modules/agentkeepalive/lib/agent.js	(revision 81bc7da776d8cda42939ef4ab350c88d13b4941f)
+++ node_modules/agentkeepalive/lib/agent.js	(revision 81bc7da776d8cda42939ef4ab350c88d13b4941f)
@@ -0,0 +1,402 @@
+'use strict';
+
+const OriginalAgent = require('http').Agent;
+const ms = require('humanize-ms');
+const debug = require('util').debuglog('agentkeepalive');
+const {
+  INIT_SOCKET,
+  CURRENT_ID,
+  CREATE_ID,
+  SOCKET_CREATED_TIME,
+  SOCKET_NAME,
+  SOCKET_REQUEST_COUNT,
+  SOCKET_REQUEST_FINISHED_COUNT,
+} = require('./constants');
+
+// OriginalAgent come from
+// - https://github.com/nodejs/node/blob/v8.12.0/lib/_http_agent.js
+// - https://github.com/nodejs/node/blob/v10.12.0/lib/_http_agent.js
+
+// node <= 10
+let defaultTimeoutListenerCount = 1;
+const majorVersion = parseInt(process.version.split('.', 1)[0].substring(1));
+if (majorVersion >= 11 && majorVersion <= 12) {
+  defaultTimeoutListenerCount = 2;
+} else if (majorVersion >= 13) {
+  defaultTimeoutListenerCount = 3;
+}
+
+function deprecate(message) {
+  console.log('[agentkeepalive:deprecated] %s', message);
+}
+
+class Agent extends OriginalAgent {
+  constructor(options) {
+    options = options || {};
+    options.keepAlive = options.keepAlive !== false;
+    // default is keep-alive and 4s free socket timeout
+    // see https://medium.com/ssense-tech/reduce-networking-errors-in-nodejs-23b4eb9f2d83
+    if (options.freeSocketTimeout === undefined) {
+      options.freeSocketTimeout = 4000;
+    }
+    // Legacy API: keepAliveTimeout should be rename to `freeSocketTimeout`
+    if (options.keepAliveTimeout) {
+      deprecate('options.keepAliveTimeout is deprecated, please use options.freeSocketTimeout instead');
+      options.freeSocketTimeout = options.keepAliveTimeout;
+      delete options.keepAliveTimeout;
+    }
+    // Legacy API: freeSocketKeepAliveTimeout should be rename to `freeSocketTimeout`
+    if (options.freeSocketKeepAliveTimeout) {
+      deprecate('options.freeSocketKeepAliveTimeout is deprecated, please use options.freeSocketTimeout instead');
+      options.freeSocketTimeout = options.freeSocketKeepAliveTimeout;
+      delete options.freeSocketKeepAliveTimeout;
+    }
+
+    // Sets the socket to timeout after timeout milliseconds of inactivity on the socket.
+    // By default is double free socket timeout.
+    if (options.timeout === undefined) {
+      // make sure socket default inactivity timeout >= 8s
+      options.timeout = Math.max(options.freeSocketTimeout * 2, 8000);
+    }
+
+    // support humanize format
+    options.timeout = ms(options.timeout);
+    options.freeSocketTimeout = ms(options.freeSocketTimeout);
+    options.socketActiveTTL = options.socketActiveTTL ? ms(options.socketActiveTTL) : 0;
+
+    super(options);
+
+    this[CURRENT_ID] = 0;
+
+    // create socket success counter
+    this.createSocketCount = 0;
+    this.createSocketCountLastCheck = 0;
+
+    this.createSocketErrorCount = 0;
+    this.createSocketErrorCountLastCheck = 0;
+
+    this.closeSocketCount = 0;
+    this.closeSocketCountLastCheck = 0;
+
+    // socket error event count
+    this.errorSocketCount = 0;
+    this.errorSocketCountLastCheck = 0;
+
+    // request finished counter
+    this.requestCount = 0;
+    this.requestCountLastCheck = 0;
+
+    // including free socket timeout counter
+    this.timeoutSocketCount = 0;
+    this.timeoutSocketCountLastCheck = 0;
+
+    this.on('free', socket => {
+      // https://github.com/nodejs/node/pull/32000
+      // Node.js native agent will check socket timeout eqs agent.options.timeout.
+      // Use the ttl or freeSocketTimeout to overwrite.
+      const timeout = this.calcSocketTimeout(socket);
+      if (timeout > 0 && socket.timeout !== timeout) {
+        socket.setTimeout(timeout);
+      }
+    });
+  }
+
+  get freeSocketKeepAliveTimeout() {
+    deprecate('agent.freeSocketKeepAliveTimeout is deprecated, please use agent.options.freeSocketTimeout instead');
+    return this.options.freeSocketTimeout;
+  }
+
+  get timeout() {
+    deprecate('agent.timeout is deprecated, please use agent.options.timeout instead');
+    return this.options.timeout;
+  }
+
+  get socketActiveTTL() {
+    deprecate('agent.socketActiveTTL is deprecated, please use agent.options.socketActiveTTL instead');
+    return this.options.socketActiveTTL;
+  }
+
+  calcSocketTimeout(socket) {
+    /**
+     * return <= 0: should free socket
+     * return > 0: should update socket timeout
+     * return undefined: not find custom timeout
+     */
+    let freeSocketTimeout = this.options.freeSocketTimeout;
+    const socketActiveTTL = this.options.socketActiveTTL;
+    if (socketActiveTTL) {
+      // check socketActiveTTL
+      const aliveTime = Date.now() - socket[SOCKET_CREATED_TIME];
+      const diff = socketActiveTTL - aliveTime;
+      if (diff <= 0) {
+        return diff;
+      }
+      if (freeSocketTimeout && diff < freeSocketTimeout) {
+        freeSocketTimeout = diff;
+      }
+    }
+    // set freeSocketTimeout
+    if (freeSocketTimeout) {
+      // set free keepalive timer
+      // try to use socket custom freeSocketTimeout first, support headers['keep-alive']
+      // https://github.com/node-modules/urllib/blob/b76053020923f4d99a1c93cf2e16e0c5ba10bacf/lib/urllib.js#L498
+      const customFreeSocketTimeout = socket.freeSocketTimeout || socket.freeSocketKeepAliveTimeout;
+      return customFreeSocketTimeout || freeSocketTimeout;
+    }
+  }
+
+  keepSocketAlive(socket) {
+    const result = super.keepSocketAlive(socket);
+    // should not keepAlive, do nothing
+    if (!result) return result;
+
+    const customTimeout = this.calcSocketTimeout(socket);
+    if (typeof customTimeout === 'undefined') {
+      return true;
+    }
+    if (customTimeout <= 0) {
+      debug('%s(requests: %s, finished: %s) free but need to destroy by TTL, request count %s, diff is %s',
+        socket[SOCKET_NAME], socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT], customTimeout);
+      return false;
+    }
+    if (socket.timeout !== customTimeout) {
+      socket.setTimeout(customTimeout);
+    }
+    return true;
+  }
+
+  // only call on addRequest
+  reuseSocket(...args) {
+    // reuseSocket(socket, req)
+    super.reuseSocket(...args);
+    const socket = args[0];
+    const req = args[1];
+    req.reusedSocket = true;
+    const agentTimeout = this.options.timeout;
+    if (getSocketTimeout(socket) !== agentTimeout) {
+      // reset timeout before use
+      socket.setTimeout(agentTimeout);
+      debug('%s reset timeout to %sms', socket[SOCKET_NAME], agentTimeout);
+    }
+    socket[SOCKET_REQUEST_COUNT]++;
+    debug('%s(requests: %s, finished: %s) reuse on addRequest, timeout %sms',
+      socket[SOCKET_NAME], socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT],
+      getSocketTimeout(socket));
+  }
+
+  [CREATE_ID]() {
+    const id = this[CURRENT_ID]++;
+    if (this[CURRENT_ID] === Number.MAX_SAFE_INTEGER) this[CURRENT_ID] = 0;
+    return id;
+  }
+
+  [INIT_SOCKET](socket, options) {
+    // bugfix here.
+    // https on node 8, 10 won't set agent.options.timeout by default
+    // TODO: need to fix on node itself
+    if (options.timeout) {
+      const timeout = getSocketTimeout(socket);
+      if (!timeout) {
+        socket.setTimeout(options.timeout);
+      }
+    }
+
+    if (this.options.keepAlive) {
+      // Disable Nagle's algorithm: http://blog.caustik.com/2012/04/08/scaling-node-js-to-100k-concurrent-connections/
+      // https://fengmk2.com/benchmark/nagle-algorithm-delayed-ack-mock.html
+      socket.setNoDelay(true);
+    }
+    this.createSocketCount++;
+    if (this.options.socketActiveTTL) {
+      socket[SOCKET_CREATED_TIME] = Date.now();
+    }
+    // don't show the hole '-----BEGIN CERTIFICATE----' key string
+    socket[SOCKET_NAME] = `sock[${this[CREATE_ID]()}#${options._agentKey}]`.split('-----BEGIN', 1)[0];
+    socket[SOCKET_REQUEST_COUNT] = 1;
+    socket[SOCKET_REQUEST_FINISHED_COUNT] = 0;
+    installListeners(this, socket, options);
+  }
+
+  createConnection(options, oncreate) {
+    let called = false;
+    const onNewCreate = (err, socket) => {
+      if (called) return;
+      called = true;
+
+      if (err) {
+        this.createSocketErrorCount++;
+        return oncreate(err);
+      }
+      this[INIT_SOCKET](socket, options);
+      oncreate(err, socket);
+    };
+
+    const newSocket = super.createConnection(options, onNewCreate);
+    if (newSocket) onNewCreate(null, newSocket);
+    return newSocket;
+  }
+
+  get statusChanged() {
+    const changed = this.createSocketCount !== this.createSocketCountLastCheck ||
+      this.createSocketErrorCount !== this.createSocketErrorCountLastCheck ||
+      this.closeSocketCount !== this.closeSocketCountLastCheck ||
+      this.errorSocketCount !== this.errorSocketCountLastCheck ||
+      this.timeoutSocketCount !== this.timeoutSocketCountLastCheck ||
+      this.requestCount !== this.requestCountLastCheck;
+    if (changed) {
+      this.createSocketCountLastCheck = this.createSocketCount;
+      this.createSocketErrorCountLastCheck = this.createSocketErrorCount;
+      this.closeSocketCountLastCheck = this.closeSocketCount;
+      this.errorSocketCountLastCheck = this.errorSocketCount;
+      this.timeoutSocketCountLastCheck = this.timeoutSocketCount;
+      this.requestCountLastCheck = this.requestCount;
+    }
+    return changed;
+  }
+
+  getCurrentStatus() {
+    return {
+      createSocketCount: this.createSocketCount,
+      createSocketErrorCount: this.createSocketErrorCount,
+      closeSocketCount: this.closeSocketCount,
+      errorSocketCount: this.errorSocketCount,
+      timeoutSocketCount: this.timeoutSocketCount,
+      requestCount: this.requestCount,
+      freeSockets: inspect(this.freeSockets),
+      sockets: inspect(this.sockets),
+      requests: inspect(this.requests),
+    };
+  }
+}
+
+// node 8 don't has timeout attribute on socket
+// https://github.com/nodejs/node/pull/21204/files#diff-e6ef024c3775d787c38487a6309e491dR408
+function getSocketTimeout(socket) {
+  return socket.timeout || socket._idleTimeout;
+}
+
+function installListeners(agent, socket, options) {
+  debug('%s create, timeout %sms', socket[SOCKET_NAME], getSocketTimeout(socket));
+
+  // listener socket events: close, timeout, error, free
+  function onFree() {
+    // create and socket.emit('free') logic
+    // https://github.com/nodejs/node/blob/master/lib/_http_agent.js#L311
+    // no req on the socket, it should be the new socket
+    if (!socket._httpMessage && socket[SOCKET_REQUEST_COUNT] === 1) return;
+
+    socket[SOCKET_REQUEST_FINISHED_COUNT]++;
+    agent.requestCount++;
+    debug('%s(requests: %s, finished: %s) free',
+      socket[SOCKET_NAME], socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT]);
+
+    // should reuse on pedding requests?
+    const name = agent.getName(options);
+    if (socket.writable && agent.requests[name] && agent.requests[name].length) {
+      // will be reuse on agent free listener
+      socket[SOCKET_REQUEST_COUNT]++;
+      debug('%s(requests: %s, finished: %s) will be reuse on agent free event',
+        socket[SOCKET_NAME], socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT]);
+    }
+  }
+  socket.on('free', onFree);
+
+  function onClose(isError) {
+    debug('%s(requests: %s, finished: %s) close, isError: %s',
+      socket[SOCKET_NAME], socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT], isError);
+    agent.closeSocketCount++;
+  }
+  socket.on('close', onClose);
+
+  // start socket timeout handler
+  function onTimeout() {
+    // onTimeout and emitRequestTimeout(_http_client.js)
+    // https://github.com/nodejs/node/blob/v12.x/lib/_http_client.js#L711
+    const listenerCount = socket.listeners('timeout').length;
+    // node <= 10, default listenerCount is 1, onTimeout
+    // 11 < node <= 12, default listenerCount is 2, onTimeout and emitRequestTimeout
+    // node >= 13, default listenerCount is 3, onTimeout,
+    //   onTimeout(https://github.com/nodejs/node/pull/32000/files#diff-5f7fb0850412c6be189faeddea6c5359R333)
+    //   and emitRequestTimeout
+    const timeout = getSocketTimeout(socket);
+    const req = socket._httpMessage;
+    const reqTimeoutListenerCount = req && req.listeners('timeout').length || 0;
+    debug('%s(requests: %s, finished: %s) timeout after %sms, listeners %s, defaultTimeoutListenerCount %s, hasHttpRequest %s, HttpRequest timeoutListenerCount %s',
+      socket[SOCKET_NAME], socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT],
+      timeout, listenerCount, defaultTimeoutListenerCount, !!req, reqTimeoutListenerCount);
+    if (debug.enabled) {
+      debug('timeout listeners: %s', socket.listeners('timeout').map(f => f.name).join(', '));
+    }
+    agent.timeoutSocketCount++;
+    const name = agent.getName(options);
+    if (agent.freeSockets[name] && agent.freeSockets[name].indexOf(socket) !== -1) {
+      // free socket timeout, destroy quietly
+      socket.destroy();
+      // Remove it from freeSockets list immediately to prevent new requests
+      // from being sent through this socket.
+      agent.removeSocket(socket, options);
+      debug('%s is free, destroy quietly', socket[SOCKET_NAME]);
+    } else {
+      // if there is no any request socket timeout handler,
+      // agent need to handle socket timeout itself.
+      //
+      // custom request socket timeout handle logic must follow these rules:
+      //  1. Destroy socket first
+      //  2. Must emit socket 'agentRemove' event tell agent remove socket
+      //     from freeSockets list immediately.
+      //     Otherise you may be get 'socket hang up' error when reuse
+      //     free socket and timeout happen in the same time.
+      if (reqTimeoutListenerCount === 0) {
+        const error = new Error('Socket timeout');
+        error.code = 'ERR_SOCKET_TIMEOUT';
+        error.timeout = timeout;
+        // must manually call socket.end() or socket.destroy() to end the connection.
+        // https://nodejs.org/dist/latest-v10.x/docs/api/net.html#net_socket_settimeout_timeout_callback
+        socket.destroy(error);
+        agent.removeSocket(socket, options);
+        debug('%s destroy with timeout error', socket[SOCKET_NAME]);
+      }
+    }
+  }
+  socket.on('timeout', onTimeout);
+
+  function onError(err) {
+    const listenerCount = socket.listeners('error').length;
+    debug('%s(requests: %s, finished: %s) error: %s, listenerCount: %s',
+      socket[SOCKET_NAME], socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT],
+      err, listenerCount);
+    agent.errorSocketCount++;
+    if (listenerCount === 1) {
+      // if socket don't contain error event handler, don't catch it, emit it again
+      debug('%s emit uncaught error event', socket[SOCKET_NAME]);
+      socket.removeListener('error', onError);
+      socket.emit('error', err);
+    }
+  }
+  socket.on('error', onError);
+
+  function onRemove() {
+    debug('%s(requests: %s, finished: %s) agentRemove',
+      socket[SOCKET_NAME],
+      socket[SOCKET_REQUEST_COUNT], socket[SOCKET_REQUEST_FINISHED_COUNT]);
+    // We need this function for cases like HTTP 'upgrade'
+    // (defined by WebSockets) where we need to remove a socket from the
+    // pool because it'll be locked up indefinitely
+    socket.removeListener('close', onClose);
+    socket.removeListener('error', onError);
+    socket.removeListener('free', onFree);
+    socket.removeListener('timeout', onTimeout);
+    socket.removeListener('agentRemove', onRemove);
+  }
+  socket.on('agentRemove', onRemove);
+}
+
+module.exports = Agent;
+
+function inspect(obj) {
+  const res = {};
+  for (const key in obj) {
+    res[key] = obj[key].length;
+  }
+  return res;
+}