DNS Service Discovery

Service Discovery with AWS Route53, Mesos, Marathon & Docker

Misakai.Dns is a service discovery project which takes advantage of AWS Route53 DNS service and Mesos Marathon to automatically register the applications deployed with Marathon to Route53 DNS. This build creates a tiny Docker image you can simply deploy into your infrastructure, and the configuration is managed on per-app basis using environment variables.

It is recommended to launch misakai/dns into your cluster using Marathon for availability. You will need only one instance of the DNS running, since it simply queries both Marathon and AWS Route53.

Deploying Misakai.DNS

In order to deploy Misakai.Dns into your cluster, submit a Marathon app with similar configuration:

{
  "id": "dns",
  "cpus": 0.1,
  "mem": 32.0,
  "instances": 1,
  "ports": [8053],
  "requirePorts": true,
  "container": {
    "type": "DOCKER",
    "docker": {
      "image": "misakai/dns:latest"
    }
  },
  "env": {
    "DNS": "dns.example.com",
    "MARATHON_HOST": "http://127.0.0.1",
    "MARATHON_AUTH": "username:password",
    "AWS_ACCESS_KEY": "XXX",
    "AWS_SECRET_KEY": "XXX",
    "AWS_REGION": "eu-west-1"
  },
  "healthChecks": [{
      "protocol": "HTTP",
      "path": "/",
      "portIndex": 0,
      "gracePeriodSeconds": 5,
      "intervalSeconds": 10,
      "timeoutSeconds": 10,
      "maxConsecutiveFailures": 3
    }
  ] 
}

The parameters:

• MARATHON_HOST: the URL of marathon REST API
• MARATHON_AUTH: the optional username:password combination for marathon REST API
• AWS_ACCESS_KEY, AWS_SECRET_KEY, AWS_REGION: AWS Access, Secret Key, and Region. This only requires Route53 access.
• DNS: optional hostname to register itself into

Using Misakai.DNS

Using the DNS is rather straightforward, you simply need to add 'DNS' environment variable* with the entire name you wish that service to register. In the example below, we have myservice.example.com where example.com will be the target hosted zone in AWS Route53 to register the service into.

"env": {
  "DNS": "myservice.example.com"
}

A more complete example:

{
  "id": "solr",
  "cpus": 0.25,
  "mem": 256.0,
  "instances": 1,
  "ports": [8990],
  "requirePorts": true,
  "container": {
    "type": "DOCKER",
    "docker": {
      "image": "manycore/solr"
    }
  },
  "env": {
    "DNS": "solr.example.com"
  }
}