Feature/ws api (#72)

initial changes to support websockets as an alternative to webhooks

lib/utils/http-requestor.js

@@ -0,0 +1,105 @@
+const bent = require('bent');
+const parseUrl = require('parse-url');
+const assert = require('assert');
+const BaseRequestor = require('./base-requestor');
+const {HookMsgTypes} = require('./constants.json');
+const snakeCaseKeys = require('./snakecase-keys');
+
+const toBase64 = (str) => Buffer.from(str || '', 'utf8').toString('base64');
+
+function basicAuth(username, password) {
+  if (!username || !password) return {};
+  const creds = `${username}:${password || ''}`;
+  const header = `Basic ${toBase64(creds)}`;
+  return {Authorization: header};
+}
+
+
+class HttpRequestor extends BaseRequestor {
+  constructor(logger, account_sid, hook, secret) {
+    super(logger, account_sid, hook, secret);
+
+    this.method = hook.method || 'POST';
+    this.authHeader = basicAuth(hook.username, hook.password);
+
+    const u = parseUrl(this.url);
+    const myPort = u.port ? `:${u.port}` : '';
+    const baseUrl = this._baseUrl = `${u.protocol}://${u.resource}${myPort}`;
+
+    this.get = bent(baseUrl, 'GET', 'buffer', 200, 201);
+    this.post = bent(baseUrl, 'POST', 'buffer', 200, 201);
+
+
+    assert(this._isAbsoluteUrl(this.url));
+    assert(['GET', 'POST'].includes(this.method));
+  }
+
+  get baseUrl() {
+    return this._baseUrl;
+  }
+
+  /**
+   * Make an HTTP request.
+   * All requests use json bodies.
+   * All requests expect a 200 statusCode on success
+   * @param {object|string} hook - may be a absolute or relative url, or an object
+   * @param {string} [hook.url] - an absolute or relative url
+   * @param {string} [hook.method] - 'GET' or 'POST'
+   * @param {string} [hook.username] - if basic auth is protecting the endpoint
+   * @param {string} [hook.password] - if basic auth is protecting the endpoint
+   * @param {object} [params] - request parameters
+   */
+  async request(type, hook, params) {
+    assert(HookMsgTypes.includes(type));
+    const payload = params ? snakeCaseKeys(params, ['customerData', 'sip']) : null;
+    const url = hook.url || hook;
+    const method = hook.method || 'POST';
+
+    assert.ok(url, 'HttpRequestor:request url was not provided');
+    assert.ok, (['GET', 'POST'].includes(method), `HttpRequestor:request method must be 'GET' or 'POST' not ${method}`);
+    const {url: urlInfo = hook, method: methodInfo = 'POST'} = hook;  // mask user/pass
+    this.logger.debug({url: urlInfo, method: methodInfo, payload}, `HttpRequestor:request ${method} ${url}`);
+    const startAt = process.hrtime();
+
+    let buf;
+    try {
+      const sigHeader = this._generateSigHeader(payload, this.secret);
+      const headers = {...sigHeader, ...this.authHeader};
+      //this.logger.info({url, headers}, 'send webhook');
+      buf = this._isRelativeUrl(url) ?
+        await this.post(url, payload, headers) :
+        await bent(method, 'buffer', 200, 201, 202)(url, payload, headers);
+    } catch (err) {
+      this.logger.error({err, secret: this.secret, baseUrl: this.baseUrl, url, statusCode: err.statusCode},
+        `web callback returned unexpected error code ${err.statusCode}`);
+      let opts = {account_sid: this.account_sid};
+      if (err.code === 'ECONNREFUSED') {
+        opts = {...opts, alert_type: this.Alerter.AlertType.WEBHOOK_CONNECTION_FAILURE, url};
+      }
+      else if (err.name === 'StatusError') {
+        opts = {...opts, alert_type: this.Alerter.AlertType.WEBHOOK_STATUS_FAILURE, url, status: err.statusCode};
+      }
+      else {
+        opts = {...opts, alert_type: this.Alerter.AlertType.WEBHOOK_CONNECTION_FAILURE, url, detail: err.message};
+      }
+      this.Alerter.writeAlerts(opts).catch((err) => this.logger.info({err, opts}, 'Error writing alert'));
+
+      throw err;
+    }
+    const rtt = this._roundTrip(startAt);
+    if (buf) this.stats.histogram('app.hook.response_time', rtt, ['hook_type:app']);
+
+    if (buf && buf.toString().length > 0) {
+      try {
+        const json = JSON.parse(buf.toString());
+        this.logger.info({response: json}, `HttpRequestor:request ${method} ${url} succeeded in ${rtt}ms`);
+        return json;
+      }
+      catch (err) {
+        //this.logger.debug({err, url, method}, `HttpRequestor:request returned non-JSON content: '${buf.toString()}'`);
+      }
+    }
+  }
+}
+
+module.exports = HttpRequestor;