Redis Cluster on AWS configuration on connect-redis and ioredis

Question

I have a Redis Cluster configured on AWS (ElastiCache).

It has a configuration endpoint and 6 nodes (3 shards).

When reading the documentation of the npm module here, it says that you have to incorporate ioredis to get it to work for a Redis cluster.

I shared the configuration below which works for a single Redis node but not for a cluster

"use strict";

// Include modules
var express = require("express"),
    cookieParser = require("cookie-parser"),
    bodyParser = require("body-parser"),
    session = require("express-session"),
    RedisStore = require("connect-redis")(session),
    middleware = require("./routes/middleware"),

    app = express(),
    sessionNameOfApp = createAppSpecificSession(configNameOfApp),

//This works but only for a single node. It doesn't work for a Redis Cluster
function createAppSpecificSession(config) {
    return session({
        store: new RedisStore({
            host: config.SESSION.host,
            port: config.SESSION.port,
            pass: config.SESSION.pass
        }),
        resave: false,
        saveUninitialized: false,
        secret: config.SESSION.cookieSecret,
        name: config.SESSION.cookieName,
        genid: sessionMethods.generateSessionId
    });
}

app.use(middleware.setUUIDOnReq);
app.use(middleware.setAgentOnReq);

// additional app modules
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
    extended: false
}));
app.use(cookieParser());

app.use(middleware.setSessionMethods);

// Include routes
require("./routes/app")(express, app);

module.exports = app;

My question is - how do I incorporate ioredis to support clustering?

This is a huge blocker for me so any help will be highly appreciated.

Looked for an example all over the net and got nothing!

Answer 1

This is what worked for me in the end:

app.js file:

"use strict";

// Include modules
var express = require("express"),
    path = require("path"),
    cookieParser = require("cookie-parser"),
    bodyParser = require("body-parser"),
    session = require("express-session"),
    RedisStore = require("connect-redis")(session),
    Redis = require('ioredis'),
    config = require("./config"),
    errorMessage = require("./errors/errorMessage"),
    sessionMethods = require("./utils/sessionMethods"),
    helmet = require("helmet"),
    middleware = require("./routes/middleware"),
    app = express(),
    session = createAppSpecificSession(config),

function createAppSpecificSession(config) {

    var redis = null;
    redis = new Redis({
        host: config.SESSION.host,
        port: config.SESSION.port,
        password: config.SESSION.password
    });

    return session({
        store: new RedisStore({
            client: redis
        }),
        resave: false,
        saveUninitialized: false,
        secret: config.SESSION.cookieSecret,
        name: config.SESSION.cookieName,
        genid: sessionMethods.generateSessionId
    });
}

app.use(helmet());
app.use(middleware.setUUIDOnReq);
app.use(middleware.setAgentOnReq);

// additional app modules
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
    extended: false
}));
app.use(cookieParser());

app.use("/", session);

// Include routes
require("./routes/app")(express, app);

module.exports = app;

And the config file:

config.js

module.exports = {
    SESSION: {
        hosts: [{
            host: "endpoint1.0001.apse1.cache.amazonaws.com",
            port: 6379,
            password: "",
        }, {
            host: "endpoint2.0002.apse1.cache.amazonaws.com",
            port: 6379,
            password: "",
        }, {
            host: "endpoint3.0003.apse1.cache.amazonaws.com",
            port: 6379,
            password: "",
        }],
        cookieName: "connect.sid",
        cookieSecret: ["blablabla", "blablabla"]
    }
};