server.js

const e = require('express');
const express = require('express');
const fetch = require('node-fetch');
const redis = require('redis');

const PORT = process.env.PORT || 5000;
const REDIS_PORT = process.env.REDIS_PORT || 6379;

const client = redis.createClient(REDIS_PORT)

const app = express();

function setResponse(username, repos){
    return `<h2>${username} has ${repos} github repos</h2>`
}

//make request to github for data
async function getRepose(req, res, next){
    try{
        console.log('getting data from github')
        const { username } = req.params;

        const response = await fetch(`https://api.github.com/users/${username}`)
        const data = await response.json();

        const repos = data.public_repos;

        // Set data to redis
        client.setex(username, 3600, repos)

        res.send(setResponse(username, repos))    
    } 
    catch (err) {
        console.error(err);
        res.status(500)
    }
}

//Cache middleware
function cache(req, res, next){
    const { username } = req.params;

    client.get(username, (err, data)=>{
        if(err) throw err;

        if(data !== null){
            res.send(setResponse(username, data))
        }else{
            next();
        }
    })
}

app.get('/repos/:username', cache, getRepose)

app.listen(PORT, ()=> console.log( `server listening on ${PORT}`))