mesos-consul

README

mesos-consul

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

Comparisons to other discovery software

Mesos-dns

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

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.

Building

docker build -t mesos-consul . 

Running

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.

Usage

Options

Option	Description
refresh	Time between refreshes of Mesos tasks
registry-auth	The basic authentication username (and optional password), separated by a colon.
registry-ssl	Use HTTPS while talking to the registry.
registry-ssl-verify	Verify certificates when connecting via SSL.
registry-ssl-cert	Path to an SSL certificate to use to authenticate to the registry server
registry-ssl-cacert	Path to a CA certificate file, containing one or more CA certificates to use to valid the reigstry server certificate
registry-token	The registry ACL token
zk*	Location of the Mesos path in Zookeeper. The default value is zk://127.0.0.1:2181/mesos

Consul Registration

Leader, Master and Follower Nodes

Role	Registration
Leader	leader.mesos.service.consul, master.mesos.service.consul
Master	master.mesos.service.consul
Follower	follower.mesos.service.consul

Mesos Tasks

Tasks are registered as task_name.service.consul

Todo

• Add support for tags
• Use task labels for metadata
• Support for multiple port tasks