Dead-simple DNS Server Daemon written in NodeJS

• A fully functional IPv4/IPv6 DNS Server ( test it yourself with dig -4 and dig -6 ) listening on TCP/UDP
• A full plugin logic to extend the DNS with custom functionality ( see below for more details )

You can install dynsdjs by simply running:

$ npm install -g dynsdjs
$ dynsd # sudo is required to bind port 80 and 53

$ git clone https://github.com/julianxhokaxhiu/dynsdjs.git
$ cd dynsdjs
$ npm install
$ npm link
$ dynsd # sudo is required to bind port 80 and 53

You can configure dynsdjs through Environment variables

• DYNSD_DNSPORT for the DNS service ( default is 53 )
• DYNSD_DNSRESOURCES to define a list of supported resources. Must be a string separated by comma ( default is A,AAAA,NS,CNAME,PTR,NAPTR,TXT,MX,SRV,SOA,TLSA )

The parameter DYNSD_DNSRESOURCES will help you to either restrict or extend the functionalities of the DNS Server. Either because of security reasons or whatever. This functionality will be a heavy whitelist, when resolving an internal domain present in the list ( injected through the init event ).

So, if you for eg. set DYNSD_DNSRESOURCES='A,AAAA' ( like in the example down here ), this means that even if the plugins will return an extended entry with other resource records ( like MX, NS, etc. ) your DNS will answer only with A and AAAA records.

$ DYNSD_DNSPORT=5353 DYNSD_DNSRESOURCES='A,AAAA' dynsd

See also package.json as a real world example.

You can extend this Daemon by creating a package that has a name that starts with dynsdjs-plugin prefix. In order to use it, it's just required to install it globally or in the current working directory, so dynsdjs will be able to auto-detect it.

$ npm install -g dynsdjs-plugin-api

The plugin at this point will be run automatically on the next restart of the daemon

In order to create a plugin, what you need is just to have a constructor that accepts as first argument the DNS daemon instance. For eg.:

module.export = function ( dns ) {
    // `dns` is the daemon instance
}

You can use the daemon instance to listen for events that are emitted from it. At the current state there are three known events. An example would be:

module.export = function ( dns ) {
    dns.on( 'init', function ( resolve, reject, data ) {
        console.log( 'Hello world!' );
      	resolve();
    })
}

The init event is emitted as soon as the DNS daemon starts. The event gives tree arguments:

• resolve: a promise function that must be called if everything on the plugin side went well.
• reject: a promise function that must be called if something went wrong.
• data.entries: this object will hold the current entries present in the daemon. You can extend/manipulate it, as long as you prefer. This object is an instance of node-cache, therefore see its API for more informations.

The structure of every entry must be Dictionary where:

• key must be a resource type ( eg. A,AAAA,etc. )
• value a valid Dictionary, composed of the keys explained in native-dns ResourceRecord documentation

This is an example of valid structure:

{
  "A": {
    "name": "awesomedomain.local",
    "address": "0.0.0.0",
    "ttl": 600
  },
  "AAAA": {
    "name": "awesomedomain.local",
    "address": "::",
    "ttl": 600
  }
}

The resolve.internal event is emitted as soon as the DNS daemon hits an internal entry. The event gives you three arguments. See the next event for more informations.

The resolve.external event is emitted as soon as the DNS daemon does not hit an internal entry, and goes therefore through external resolvers. The event gives you three arguments:

• resolve: a promise function that must be called if everything on the plugin side went well.
• reject: a promise function that must be called if something went wrong.
• data.req: an object representing the current request coming from the native-dns server instance.
• data.res: an object representing the current response object coming from the native-dns server instance.

A current list of plugins that are available can be found here:

• NPM: https://www.npmjs.com/search?q=dynsdjs-plugin
• Github: https://github.com/dynsdjs?q=dynsdjs-plugin

See LICENSE