docker-etcd-registrator

Docker Hub

Registers all swarm services in a etcd in a format suitable for nginx-autoproxy. Services are registered at key: /services/:service_name.

Services are put into BASE_DIR/{service_name} key in the JSON format. Json contains following fields:

{
  "name": "{service_name}",
  "address": "{service_name}:{published_port}",
  "Env": [ "copy of service environment variables" ],
  "{docker_service_label}": "{label_value}"
}

Example:

{
  "name": "play_app",
  "address": "play_app:9000",
  "Env": [ "DEBUG=true", "DB_HOST=mysql" ],
  "test_label": "foo"
}

If docker service is removed it will also be removed from the etcd. But the actual number of containers for specific service is ignored.

Run steps:

1. Create a swarm cluster.
2. Start etcd service:

docker service create --name etcd \
  --network swarm_network \
  --publish 2380 --publish 2379:2379 \ 
  quay.io/coreos/etcd:latest etcd \
    -advertise-client-urls http://etcd:2379 \
    -listen-client-urls http://0.0.0.0:2379

3. Run registrator on a swarm manager:

docker service create --name registrator \
  --network swarm_network \
  --constraint 'node.role == manager' \
  --mount type=bind,source=/var/run/docker.sock,target=/var/run/docker.sock \
  --env ETCD_HOST=etcd --env ETCD_PORT=2379 \
  sergkh/docker-etcd-registrator

Configuration options

Configuration can be set using following environment variables:

• ETCD_HOST – Etcd daemon host (default: etcd)
• ETCD_PORT – Etcd daemon port (default: 2379)
• BASE_DIR – Base directroy in the etcd where services will be registered (default: /services)
• UPDATE_INTERVAL – Docker polling interval in seconds (default: 120)
• RUN_ONCE – Stops container after services update. Possible values are: True/False (default: False)

Ignoring a service

Service can be ignored by simply adding a label registry_ignore:

docker service create --name kafka --label registry_ignore wurstmeister/kafka

Contributions

Contributions are welcomed. Thanks @fsanaulla for his contributions.