Mesos to Consul bridge for service discovery.

Mesos-consul automatically registers/deregisters services run as Mesos tasks.

This means if you have a Mesos task called application, this program will register the application in Consul, and it will be exposed via DNS as application.service.consul.

This program also does Mesos leader discovery, so that leader.mesos.service.consul will point to the current leader.

Table of Contents

• mesos-consul
  • Comparisons to other discovery software
    • [Mesos-dns](#mesos-dnshttpsgithubcommesospheremesos-dns)
    • [Registrator](#registratorhttpsgithubcomgliderlabsregistrator)
  • Building
  • Running
  • Usage
    • Options
    • Consul Registration
      • Leader, Master and Follower Nodes
      • Mesos Tasks
  • Todo

This project is similar to mesos-dns in that it polls Mesos to get information about tasks. However, instead of exposing this information via a built-in DNS server, we populate Consul service discovery with this information. Consul then exposes the services via DNS and via its API.

Benefits of using Consul:

• Integration with other tools like consul-template
• Multi-DC DNS lookups
• Configurable health checks that run on each system

Registrator is another tool that populates Consul (and other backends like etcd) with the status of Docker containers. However, Registrator is currently limited to reporting on Docker containers and does not track Mesos tasks.

docker build -t mesos-consul . 

Mesos-consul can be run in a Docker container via Marathon. If your Zookeeper and Marathon services are registered in consul, you can use .service.consul to find them, otherwise change the vaules for your environment:

curl -X POST -d@mesos-consul.json -H "Content-Type: application/json" http://marathon.service.consul:8080/v2/apps'

Where mesos-consul.json is similar to (replacing the image with your image):

{
  "args": [
    "--zk=zk://zookeeper.service.consul:2181/mesos"
  ],  
  "container": {
    "type": "DOCKER",
    "docker": {
      "network": "BRIDGE",
      "image": "{{ mesos_consul_image }}:{{ mesos_consul_image_tag }}"
    }   
  },  
  "id": "mesos-consul",
  "instances": 1,
  "cpus": 0.1,
  "mem": 256 
}

You can add options to authenticate via basic http or Consul token.

Tasks are registered as task_name.service.consul

Tags can be added to consul by using labels in Mesos. If you are using Marathon you can add a label called tags to your service definition with a comma-separated list of strings that will be registered in consul as tags.

For example, in your marathon service definition:

{
  "id": "tagging-test",
  "container": { /*...*/},
  "labels": {
    "tags": "label1,label2,label3"
  }
}

This will result in a service tagging-test being created in consul with 3 separate tags: label1 label2 and label3

// GET /v1/catalog/service/tagging-test
[
  {
    Node: "consul",
    Address: "10.0.2.15",
    ServiceID: "mesos-consul:10.0.2.15:tagging-test:31562",
    ServiceName: "tagging-test5",
    ServiceTags: [
      "label1",
      "label2",
      "label3"
    ],
    ServiceAddress: "10.0.2.15",
    ServicePort: 31562
  }
]

• Use task labels for metadata
• Support for multiple port tasks