2014_consul.org

Consul

Consul

• Service Discovery
• Failure Detection
• Multi Datacenter
• Key/Value Storage

Architecture

Install

$ mkdir consul
$ wget https://dl.bintray.com/mitchellh/consul/0.3.1_linux_amd64.zip
$ unzip -d consul 0.3.1_linux_amd64.zip
$ ln -s /opt/consul/consul /usr/local/

Server

$ consul agent -server -bootstrap -client=172.17.0.31 -dc=local -node=consul1 -data-dir=/root/consul -ui-dir=/opt/consul/dist -bind=172.17.0.31

Client

$ consul agent -dc=local -node=consul2 -data-dir=/tmp/consul2 -bind=172.17.0.32 -join=172.17.0.31

HTTP

$ curl -s http://172.17.0.62:8500/v1/catalog/nodes | jq .
$ curl -s http://172.17.0.62:8500/v1/health/node/consul2 | jq .

DNS

• <node>.node.<datacenter>.<domain>
• <tag>.<service>.service.<datacenter>.<domain>

$ dig @172.17.0.62 -p 8600 node.consul any
$ dig @172.17.0.62 -p 8600 consul.service.consul any

Service

$ curl -s http://172.17.0.62:8500/v1/health/checks/database | jq .

$ cat services/database.json 
{
  "service": {
    "name": "database",
    "tags": [ "mysql" ],
    "port": 5000,
    "check": {
      "script": "<Some Awesome Script>"
      "interval": "10s"
    }
  }
}

$ cat services/unicorn.json 
{
  "service": {
    "name": "unicorn",
    "tags": [ "ver1" ],
    "port": 3000
  }
}