Koa-redis-snowman NPM

koa-redis

Redis storage for Koa session middleware/cache with Sentinel and Cluster support

A fork of koa-redis, rewritten in typescript and with better support for koa-session

Install

npm install koa-redis

yarn:

yarn add koa-redis

Usage

koa-redis-snowman works with koa-session (a basic session middleware for koa).

Basic

const Session = require('koa-session-snowman');
const RedisStore = require('koa-redis');
const koa = require('koa');

const app = koa();
app.keys = ['keys', 'keykeys'];
app.use(new Session({
  store: new RedisStore({
    // Options specified here
  })
}, app));

app.use(function *() {
  switch (this.path) {
  case '/get':
    get.call(this);
    break;
  case '/remove':
    remove.call(this);
    break;
  case '/regenerate':
    yield regenerate.call(this);
    break;
  }
});

function get() {
  const session = this.session;
  session.count = session.count || 0;
  session.count++;
  this.body = session.count;
}

function remove() {
  this.session = null;
  this.body = 0;
}

function *regenerate() {
  get.call(this);
  yield this.regenerateSession();
  get.call(this);
}

app.listen(8080);

Sentinel

const Session = require('koa-session');
const RedisStore = require('koa-redis');
const koa = require('koa');

const app = koa();
app.keys = ['keys', 'keykeys'];
app.use(new Session({
  store: new RedisStore({
    // Options specified here
    // <https://github.com/luin/ioredis#sentinel>
    sentinels: [
      { host: 'localhost', port: 26379 },
      { host: 'localhost', port: 26380 }
      // ...
    ],
    name: 'mymaster'
  })
}, app));

// ...

Cluster

const Session = require('koa-session');
const RedisStore = require('koa-redis');
const koa = require('koa');

const app = koa();
app.keys = ['keys', 'keykeys'];
app.use(new Session({
  store: new RedisStore({
    // Options specified here
    // <https://github.com/luin/ioredis#cluster>
    isRedisCluster: true,
    nodes: [
      {
        port: 6380,
        host: '127.0.0.1'
      },
      {
        port: 6381,
        host: '127.0.0.1'
      }
      // ...
    ],
    // <https://github.com/luin/ioredis/blob/master/API.md#new-clusterstartupnodes-options>
    clusterOptions: {
      // ...
      redisOptions: {
        // ...
      }
    }
  })
}, app));

// ...

Options

all ioredis options - Useful things include url, host, port, and path to the server. Defaults to 127.0.0.1:6379
db (number) - will run client.select(db) after connection
client (object) - supply your own client, all other options are ignored unless duplicate is also supplied
duplicate (boolean) - When true, it will run client.duplicate() on the supplied client and use all other options supplied. This is useful if you want to select a different DB for sessions but also want to base from the same client object.
serialize - Used to serialize the data that is saved into the store.
unserialize - Used to unserialize the data that is fetched from the store.
isRedisCluster (boolean) - Used for creating a Redis cluster instance per ioredis Cluster options, if set to true, then a new Redis cluster will be instantiated with new Redis.Cluster(options.nodes, options.clusterOptions) (see Cluster docs for more info).
nodes (array) - Conditionally used for creating a Redis cluster instance when isRedisCluster option is true, this is the first argument passed to new Redis.Cluster and contains a list of all the nodes of the cluster ou want to connect to (see Cluster docs for more info).
clusterOptions (object) - Conditionally used for created a Redi cluster instance when isRedisCluster option is true, this is the second argument passed to new Redis.Cluster and contains options, such as redisOptions (see Cluster docs for more info).
DEPRECATED: old options - auth_pass and pass have been replaced with password, and socket has been replaced with path, however all of these options are backwards compatible.

Events

See the ioredis docs for more info.

Note that as of v4.0.0 the disconnect and warning events are removed as ioredis does not support them. The disconnect event is deprecated, although it is still emitted when end events are emitted.

API

These are some the functions that koa-session uses that you can use manually. You will need to initialize differently than the example above:

const Session = require('koa-session');
const RedisStore = require('koa-redis')({
  // Options specified here
});
const app = require('koa')();

app.keys = ['keys', 'keykeys'];
app.use(new Session({
  store: new RedisStore
}, app));

module(options)

Initialize the Redis connection with the optionally provided options (see above). The variable session below references this.

session.get(sid)

Generator that gets a session by ID. Returns parsed JSON is exists, null if it does not exist, and nothing upon error.

session.set(sid, sess, ttl)

Generator that sets a JSON session by ID with an optional time-to-live (ttl) in milliseconds. Yields ioredis's client.set() or client.setex().

session.destroy(sid)

Generator that destroys a session (removes it from Redis) by ID. Tields ioredis's client.del().

session.quit()

Generator that stops a Redis session after everything in the queue has completed. Yields ioredis's client.quit().

Benchmark

Note: these are from the generator based version, should retry with new async version.

Server	Transaction rate	Response time
connect without session	6763.56 trans/sec	0.01 secs
koa without session	5684.75 trans/sec	0.01 secs
connect with session	2759.70 trans/sec	0.02 secs
koa with session	2355.38 trans/sec	0.02 secs

Detailed benchmark report here

Testing

Start a Redis server on localhost:6379. You can use redis-windows if you are on Windows or just want a quick VM-based server.
Clone the repository and run npm i in it (Windows should work fine).
If you want to see debug output, turn on the prompt's DEBUG flag.
Run npm test to run the tests and generate coverage. To run the tests without generating coverage, run npm run-script test-only.