egg-session

Session plugin for egg, based on koa-session.

Install

$ npm i egg-session --save

Usage

egg-session is a built-in plugin in egg and enabled by default.

// {app_root}/config/plugin.js
exports.session = true; // enable by default

External Store

egg-session support external store, you can store your sessions in redis, memcached or other databases.

For example, if you want to store session in redis, you must:

1. Dependent egg-redis

npm i --save egg-redis

2. Import egg-redis as a plugin and set the configuration

// config/plugin.js
exports.redis = {
  enable: true,
  package: 'egg-redis',
};

// config/config.default.js
exports.redis = {
  // your redis configurations
};

3. Implement a session store with redis

// app.js

module.exports = app => {
  // set redis session store
  // session store must have 3 methods
  // define sessionStore in `app.js` so you can access `app.redis`
  app.sessionStore = {
    * get(key) {
      const res = yield app.redis.get(key);
      if (!res) return null;
      return JSON.parse(res);
    },

    * set(key, value, maxAge) {
      // maxAge not present means session cookies
      // we can't exactly know the maxAge and just set an appropriate value like one day
      if (!maxAge) maxAge = 24 * 60 * 60 * 1000;
      value = JSON.stringify(value);
      yield app.redis.set(key, value, 'PX', maxAge);
    },

    * destroy(key) {
      yield app.redis.del(key);
    },
  };

  // session store can be a session store class
  // app.sessionStore = class Store {
  //   constructor(app) {
  //     this.app = app;
  //   }
  //   * get() {}
  //   * set() {}
  //   * destroy() {}
  // };
};

Once you use external session store, session is strong dependent on your external store, you can't access session if your external store is down. Use external session stores only if necessary, avoid use session as a cache, keep session lean and stored by cookie!

Configuration

Support all configurations in koa-session.

View the default configurations

Questions & Suggestions

Please open an issue here.

License

MIT