Unable to connect with redis in app.get method - node.js

Question

I am trying to learn use case of redis. As each tutorial is suggesting that it is better for caching a data.
I have made a simple demo where I am trying to connect with redis server in a web service get method.
var redis = require('redis');
var client = redis.createClient();
var express = require('express')
var app = express()
var port = process.env.PORT || 8080; // <== this is must
app.get('/fetch_offers', function (req, res) {
client.on('connect', function() {
console.log('connected');
});
});
app.listen(port, function () {
console.log(port)
})
I am trying to access it on localhost machine like http://localhost:8080/fetch_offers
I debugged it using console.log method but it does not print connected message. When I make this method outside the app.get... then it prints on executing node app.js.
I want it should make a redis connection on hitting a URL. I am not sure what is best way ? Can anyone help me ?
var redis = require('redis');
var client = redis.createClient();
var express = require('express')
var app = express()
var port = process.env.PORT || 8080; // <== this is must
client.on('connect', function() {
console.log('connected');
});
app.get('/fetch_offers', function (req, res) {
});
app.listen(port, function () {
console.log(port)
})
What wrong I am doing here ?

Answer 1

It doesn't print connection message because the event fires well before you hit the endpoint - at which point nothing is listening for it and it gets lost. Try something like this:
var redis = require('redis');
var client = redis.createClient();
client.on('connect', () => {
console.log('Redis connected');
});
client.on('ready', () => {
console.log('Redis ready');
});
client.on('error', (err) => {
console.log('Redis error:', err.message);
});
and then in your route handler you can use ping to see if you're connected:
app.get('/fetch_offers', function (req, res) {
client.ping((err, data) => {
if (err) {
console.log('Ping error:', err);
return;
}
console.log('Ping response:', data);
});
});
It would be slightly easier if you use promise-redis and async/await:
app.get('/fetch_offers', async (req, res) => {
try {
console.log('Ping response:', await client.ping());
} catch (err) {
console.log('Ping error:', err);
}
});