# Swarm

## Setup Docker EasyHAProxy

This method involves using a Docker Swarm installation to discover containers and configure HAProxy.

EasyHAProxy inspects Docker containers within the Swarm and retrieves labels to configure HAProxy. Once it identifies a container with at least the label 'easyhaproxy.http.host,' it configures HAProxy to redirect traffic to that container. To accomplish this, EasyHAProxy may need to attach the same network to its container.

Utilizing Docker Swarm offers several advantages, including:
 - Container Discovery: Docker Swarm facilitates the discovery of containers within the cluster, 
   streamlining the process of identifying services for HAProxy configuration.
 - Remote Node Management: Docker Swarm allows for the management of containers across multiple nodes, 
   providing flexibility and scalability in deploying services while ensuring seamless HAProxy configuration across the cluster.

It's recommended to create a network external to EasyHAProxy.

Limitations:
 - You cannot mix Docker containers with Swarm containers.
 - This method does not work with containers that use the '--network=host' option. (see [limitations](limitations.md))

e.g.:

```bash
docker network create -d overlay --attachable easyhaproxy
```

And then deploy the EasyHAProxy stack:

```yaml
version: "3"

services:
  haproxy:
    image: byjg/easy-haproxy:4.3.1-rc1
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    deploy:
      replicas: 1
    environment:
      EASYHAPROXY_DISCOVER: swarm
      EASYHAPROXY_SSL_MODE: "loose"
      HAPROXY_CUSTOMERRORS: "true"
      HAPROXY_USERNAME: admin
      HAPROXY_PASSWORD: password
      HAPROXY_STATS_PORT: 1936
    ports:
      - "80:80/tcp"
      - "443:443/tcp"
      - "1936:1936/tcp"
    networks:
      - easyhaproxy

networks:
  easyhaproxy:
    external: true
```

And then:

```bash
docker stack deploy --compose-file docker-compose.yml easyhaproxy
```

Mapping to `/var/run/docker.sock` is necessary to discover the docker containers and get the labels;

**Do not** add more than one replica for EasyHAProxy. To understand that see [limitations](limitations.md) page.

## Running containers

To make your containers "discoverable" by EasyHAProxy, that is the minimum configuration you need:

```yaml
version: "3"

services:
  container:
    image: my/image:tag
    deploy:
      replicas: 1
      labels:
        easyhaproxy.http.host: host1.local
        easyhaproxy.http.port: 80
        easyhaproxy.http.localport: 8080
    networks:
      - easyhaproxy

networks:
  easyhaproxy:
    external: true
```

Once the container is running, EasyHAProxy will detect automatically and start to redirect all traffic from `example.org:80` to your container.

You don't need to expose any port in your container.

Please follow the [docker label configuration](container-labels.md) to see other configurations available.

## Setup the EasyHAProxy container

You can configure the behavior of the EasyHAProxy by setup specific environment variables. To get a list of the variables, please follow the [environment variable guide](environment-variable.md)

## More information

You can refer to the [Docker Documentation](docker.md) to get other detailed instructions.

----
[Open source ByJG](http://opensource.byjg.com)