docker-easy-haproxy/docs/swarm.md

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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.

:::tip Docker Swarm Advantages

• 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.

:::warning Limitations

• You cannot mix Docker containers with Swarm containers.
• This method does not work with containers that use the --network=host option. See limitations for details. :::

For example:

docker network create -d overlay --attachable easyhaproxy

And then deploy the EasyHAProxy stack:

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

Deploy the stack:

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;

:::danger Single Replica Only Do not add more than one replica for EasyHAProxy. To understand why, see the limitations page. :::

Running containers

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

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 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

More information

You can refer to the Docker Documentation to get other detailed instructions.

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Open source ByJG