redis-sessions

Redis Sessions

There is a need to maintain a universal session across different application server platforms.

This is a NodeJS module to keep sessions in a Redis datastore and add some useful methods.

Installation

npm install redis-sessions

Basics

• Every session belongs to an app (e.g. webapp, app_cust123).
• A session is created by supplying the app and an id (usually the unique id of the user). A token will be returned.
• A session is queried with the app and token.
• Additional data (key/value) can be stored in the session.
• A session can be killed with the app and token.
• All sessions of an app can be killed.

Additional methods

• TODO: Get an array of all sessions of an app, complete with lastactivity, ip which were active within the last n seconds.
• Get the amount of active sessions of an app within the last n seconds.
• TODO: Get all sessions of a single id.
• TODO: Kill all sessions that belong to a single id. E.g. log out user123 on all devices.

Usage in NodeJS

Setup and creating the first session

RedisSessions = require("../redis-sessions");
rs = new RedisSessions();

app = "myapp";

// Set a session for `user1001`

rs.create({
  app: app,
  id: "user1001"},
  function(err, resp) {
    // resp should be something like 
   // {token: "r30kKwv3sA6ExrJ9OmLSm4Wo3nt9MQA1yG94wn6ByFbNrVWhcwAyOM7Zhfxqh8fe"}
  });

Add some data to the session

rs.set({
  app: app,
  token: "r30kKwv3sA6ExrJ9OmLSm4Wo3nt9MQA1yG94wn6ByFbNrVWhcwAyOM7Zhfxqh8fe",
  d: {
    "unread_msgs": 12,
    "last_action": "/read/news",
    "birthday": "2013-08-13"
  }},
  function(err, resp) {
    /*
    resp contains the session with the new values:

    {  
      "id":"user1001",
      "r": 1,
      "w": 2,
      "idle": 1,
      "ttl": 7200, 
      "d":
        {
          "unread_msgs": 12,
          "last_action": "/read/news",
          "birthday": "2013-08-13"
        }
    }
    */  
  });

Get a session for a token

rs.get({
  app: app,
  token: "r30kKwv3sA6ExrJ9OmLSm4Wo3nt9MQA1yG94wn6ByFbNrVWhcwAyOM7Zhfxqh8fe"},
  function(err, resp) {
    /*
    resp contains the session:

    {  
      "id":"user1001",
      "r": 1,  // The number of reads on this token
      "w": 1,  // The number of writes on this token
      "idle": 21,  // The idle time in seconds.
      "ttl": 7200, // Timeout after 7200 idle time
      "d":
        {
          "unread_msgs": 12,
          "last_action": "/read/news",
          "birthday": "2013-08-13"
        }
    }

    */
  });

Set/Update/Delete

Set/Update/Delete parameters by supplying app, token and some data d.
The d object contains a simple key/value list where values
can be string, number, boolean or null.
To remove keys set them to null, keys that are not supplied will not be touched.

rs.set({
  app: app,
  token: "r30kKwv3sA6ExrJ9OmLSm4Wo3nt9MQA1yG94wn6ByFbNrVWhcwAyOM7Zhfxqh8fe",
  d: {
      "unread_msgs": null
      "last_action": "/read/msg/2121"
  }},
  function(err, resp) {
    /*
    resp contains the session with modified values:

    {  
      "id":"user1001",
      "r": 1,
      "w": 2,
      "idle": 1,
      "ttl": 7200, 
      "d":
        {
          "last_action": "/read/msg/2121",
          "birthday": "2013-08-13"
        }
    }
    */  
  });