Simple redis cache

auth.js

async function getAuthResponse(req) {
  let serviceRes = await cacheController.getCachedCustomerAuth(req.headers.authorization);
  if (serviceRes === null) {
    serviceRes = await CustomerService.isAuthenticated(req);
    cacheController.cacheCustomerAuth(req.headers.authorization, serviceRes);
  }
  return serviceRes;
}

cache_controller.js

const RedisClient = require('./redis_client');
const hydra = require('hydra-express').getHydra();
const KEY_CACHE = 'cache';

class CacheController {
  /**
   * @param {RedisClient} redisClient 
   */
  constructor(redisClient) {
    this._redisClient = redisClient;
  }

  cacheCustomerAuth(token, customerResponse) {
    this._redisClient.cacheValue(this._formatCacheKey(token), JSON.stringify(customerResponse));
  }

  getCachedCustomerAuth(token) {
    return this._redisClient.getCachedValue(this._formatCacheKey(token)).then(JSON.parse);
  }

  _formatCacheKey(key) {
    return `${KEY_CACHE}:${hydra.getServiceName()}:${key}`;
  }
}

module.exports = new CacheController(new RedisClient());

redis_client.js

const redis = require('redis');
const config = require('../config.json');

const REDIS_CONFIG = config['hydra']['redis'];
const CACHE_EXPIRE_SEC = 3600;

class RedisClient {
  constructor() {
    this._client = redis.createClient(REDIS_CONFIG['url']);
  }

  cacheValue(key, value) {
    this._client.setex(key, CACHE_EXPIRE_SEC, value);
  }

  getCachedValue(key) {
    return new Promise((resolve, reject) => {
      this._client.get(key, (err, reply) => {
        if (err) {
          reject(err);
        } else {
          resolve(reply);
        }
      });
    });
  }
}

module.exports = RedisClient;