Using Redis to cache API calls (Node.js)

api-query.js

const rp = require('request-promise');
const { to } = require('await-to-js');
const crypto = require('crypto');
const redisClient = require('./redis-client');

/**
 * Execute an API call
 * @param {String}        uri       API URI
 * @param {Number}        ttl       Expiration of cache in seconds
 */
const cachingQuery = (module.exports = (uri, ttl = 0) => {
  return new Promise(async (resolve, reject) => {
    let err, results;

    const hash = crypto
      .createHash('sha1')
      .update(uri)
      .digest('hex');
    redisClient.getCache(hash, async (err, data) => {
      if (err || !data) {
        [err, results] = await to(_execute(uri, ttl));
        if (err) return reject(err);
        return resolve(results);
      } else {
        return resolve(data);
      }
    });
  });
});

function _execute(uri, ttl) {
  return new Promise((resolve, reject) => {
    const hash = crypto
      .createHash('sha1')
      .update(uri)
      .digest('hex');
    
    const options = {
      uri,
      headers: {},
      json: true,
    };
    rp(options)
      .then(result => {
        redisClient.setCache(hash, ttl, result, (err, data) => {
          if (err || !data) return reject('Error getting redis cache');
          return resolve(result);
        });
      })
      .catch(error => reject(error));
  });
}

index.js

#!/usr/bin/env node
'use strict';

require('dotenv').config();

const rp = require('request-promise');
const query = require('./api-query');

const retrieveData = async () => {
  let projects = await query('https://api.example.com/v1/projects', 3600); // ttl in seconds
  return console.log(projects);
};

(async function() {
  await retrieveData();
})();

redis-client.js

const redis = require('redis');
const multicb = require('multicb');

const redisClient = (module.exports = redis.createClient(process.env.REDIS_PORT, process.env.REDIS_HOST, { no_ready_check: true }));

if (process.env.REDIS_PASSWORD) {
  redisClient.auth(process.env.REDIS_PASSWORD);
}

redisClient.on('error', err => console.log('Redis ' + err));

setInterval(function() {
  redisClient.ping();
}, 1000 * 30);

// =====================
// API caching functions
// =====================
redisClient.getCache = (key, next) => {
  redisClient.get(`api:${key}`, (err, result) => {
    if (err || !result) return next(err);
    return next(null, JSON.parse(result));
  });
};

redisClient.setCache = (key, ttl, data, next) => {
  redisClient.setex(`api:${key}`, ttl, JSON.stringify(data), (err, result) => {
    if (err || !result) return next(err);
    return next(null, result);
  });
};