index.js

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();

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

// Make request to Github for Data
async function getRepos(req, res, next){
    try {
        console.log('Fetching Data ....');
        const { username } = req.params;
        const response = await fetch(`https://api.github.com/users/${username}`);

        const data = await response.json();

        const repos = data.public_repos;

        client.setex(username,3600,repos);

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

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, getRepos);

app.listen(5000,()=>{
    console.log(`App Listening on port ${PORT}`);
});