keycloak-request-token/index.js

Simple utility to request a token from a Keycloak Server

/**
 * @module keycloak-request-token
 */

'use strict';

const http = require('http');
const https = require('https');
const url = require('url');
const querystring = require('querystring');

const tokenUrl = 'protocol/openid-connect/token';

/**
  Requests a new Keycloak Access Token
  @param {string} baseUrl - The baseurl for the Keycloak server - ex: http://localhost:8080/auth,
  @param {object} settings - an object containing the settings
  @param {string} settings.username - The username to login to the keycloak server - ex: admin
  @param {string} settings.password - The password to login to the keycloak server - ex: *****
  @param {string} settings.grant_type - the type of authentication mechanism - ex: password,
  @param {string} settings.client_id - the id of the client that is registered with Keycloak to connect to - ex: admin-cli
  @param {string} settings.realmName - the name of the realm to login to - defaults to 'masterg'
  @returns {Promise} A promise that will resolve with the Access Token String.
  @instance
  @example

  const tokenRequester = require('keycloak-request-token');
  const baseUrl = 'http://127.0.0.1:8080/auth';
  const settings = {
      username: 'admin',
      password: 'admi',
      grant_type: 'password',
      client_id: 'admin-cli'
  };

  tokenRequester(baseUrl, settings)
    .then((token) => {
      console.log(token);
    }).catch((err) => {
      console.log('err', err);
    });
 */
function getToken(baseUrl, settings) {
  return new Promise((resolve, reject) => {
    settings = settings || {};

    settings.realmName = settings.realmName ? settings.realmName : 'master';

    const options = url.parse(`${baseUrl}/realms/${settings.realmName}/${tokenUrl}`);

    options.headers = {
      'Content-type': 'application/x-www-form-urlencoded'
    };

    options.method = 'POST';

    options.data = settings;

    const caller = (options.protocol === 'https:') ? https : http;
    const data = [];
    const req = caller.request(options, (res) => {
      res.on('data', (chunk) => {
        data.push(chunk);
      }).on('end', () => {
        try {
          const stringData = Buffer.concat(data).toString();
          // need to look for the 404 since the return value is not really JSON but HTML
          if (res.statusCode === 404) {
            return reject(stringData);
          }

          const parsedData = JSON.parse(stringData);
          if (res.statusCode !== 200) {
            return reject(parsedData);
          }

          const token = parsedData.access_token;
          resolve(token);
        } catch(e) {
          reject(e);
        }
      });
    });

    req.on('error', (e) => {
      reject(e);
    });

    req.write(querystring.stringify(options.data));
    req.end();
  });
}

module.exports = getToken;