What is connect-redis?
The connect-redis npm package is a Redis session store for Express and Connect. It allows you to store session data in a Redis database, which can help with scaling applications by providing a centralized session store.
What are connect-redis's main functionalities?
Basic Setup
This code demonstrates how to set up a basic Express application with connect-redis as the session store. It configures the session middleware to use Redis for storing session data.
const session = require('express-session');
const RedisStore = require('connect-redis')(session);
const express = require('express');
const app = express();
app.use(session({
store: new RedisStore({
host: 'localhost',
port: 6379
}),
secret: 'your secret',
resave: false,
saveUninitialized: false
}));
app.get('/', (req, res) => {
res.send('Hello World!');
});
app.listen(3000, () => {
console.log('Server is running on port 3000');
});
Custom Redis Client
This code demonstrates how to use a custom Redis client with connect-redis. This can be useful if you need to configure the Redis client with specific options or use an existing Redis client instance.
const session = require('express-session');
const RedisStore = require('connect-redis')(session);
const express = require('express');
const redis = require('redis');
const app = express();
const redisClient = redis.createClient({
host: 'localhost',
port: 6379
});
app.use(session({
store: new RedisStore({ client: redisClient }),
secret: 'your secret',
resave: false,
saveUninitialized: false
}));
app.get('/', (req, res) => {
res.send('Hello World!');
});
app.listen(3000, () => {
console.log('Server is running on port 3000');
});
Advanced Configuration
This code demonstrates advanced configuration options for connect-redis, such as setting the time-to-live (ttl) for sessions and enabling error logging.
const session = require('express-session');
const RedisStore = require('connect-redis')(session);
const express = require('express');
const app = express();
app.use(session({
store: new RedisStore({
host: 'localhost',
port: 6379,
ttl: 260,
logErrors: true
}),
secret: 'your secret',
resave: false,
saveUninitialized: false
}));
app.get('/', (req, res) => {
res.send('Hello World!');
});
app.listen(3000, () => {
console.log('Server is running on port 3000');
});
Other packages similar to connect-redis
express-session
express-session is a general-purpose session middleware for Express. It supports various session stores, including in-memory, file-based, and database-backed stores. Unlike connect-redis, it does not provide a Redis-specific store out of the box but can be extended with other packages.
connect-mongo
connect-mongo is a MongoDB session store for Express and Connect. It provides similar functionality to connect-redis but uses MongoDB as the backend store instead of Redis. It is useful for applications that already use MongoDB and want to keep session data in the same database.
express-mysql-session
express-mysql-session is a MySQL session store for Express. It provides similar functionality to connect-redis but uses MySQL as the backend store. It is useful for applications that use MySQL and want to store session data in a relational database.
Connect Redis
connect-redis is a Redis session store backed by node_redis, and is insanely fast :). Requires redis >= 2.0.0
for the SETEX command.
Installation
$ npm install connect-redis
A note for Express 3.x users
In order to use the latest connect-redis
you also have to use express-session
instead of the default connect session
middleware.
$ npm install express-session
Then follow the usage instructions below.
Options
A Redis client is required. An existing client can be passed directly using the client
param or created for you using the host
, port
, or socket
params.
client
An existing clienthost
Redis server hostnameport
Redis server portnosocket
Redis server unix_socket
The following additional params may be included:
ttl
Redis session TTL (expiration) in secondsdisableTTL
disables setting TTL, keys will stay in redis until evicted by other means (overides ttl
)db
Database index to usepass
Password for Redis authenticationprefix
Key prefix defaulting to "sess:"unref
Set true
to unref the Redis client. Warning: this is an experimental feature.serializer
An object containing stringify
and parse
methods compatible with Javascript's JSON
to override the serializer used
Any options not included in this list will be passed to the redis createClient()
method directly.
Usage
Pass the express-session
store into connect-redis
to create a RedisStore
constructor.
var session = require('express-session');
var RedisStore = require('connect-redis')(session);
app.use(session({
store: new RedisStore(options),
secret: 'keyboard cat'
}));
Custom Redis clients
Clients other than node_redis
will work if they support the same interface. Just pass the client instance as the client
configuration option. Known supported clients include:
- ioredis - adds support for Redis Sentinel and Cluster
FAQ
Can I use a URL scheme to make a connection?
Since node_redis
which this library wraps does not include the ability to create a client from a URL. Neither does this library. However, there's a separate module that can be used in conjunction to get this behavior.
How do I handle lost connections to Redis?
By default, the node_redis
client will auto-reconnect when a connection is lost. But requests may come in during that time. In express, one way this scenario can be handled is including a "session check" after setting up a session (checking for the existence of req.session
):
app.use(session( ))
app.use(function (req, res, next) {
if (!req.session) {
return next(new Error('oh no'))
}
next()
})
If you want to retry, here is another option.
License
MIT