itamae/cookbooks/loki/templates/etc/consul.d/service-loki.json.erb

{
  "service": {
    "name": "loki",
    "port": 3100,
    "check":{
      "tcp": "<%= @ipaddr %>:3100",
      "interval": "60s",
      "timeout": "1s",
      "success_before_passing": 3
    }
  }
}