HAProxy, Backend, ZEO container example#

This example is a very simple setup with one or more backend instances accessing a ZEO server and data being persisted in a Docker volume.

HAProxy is used for load balancing in this example. We will use the image plone/plone-haproxy.

Setup#

Create a directory for your project, and inside it create a docker-compose.yml file that starts your Plone instance and the ZEO instance with volume mounts for data persistence.

version: "3"
services:

  lb:
    image: plone/plone-haproxy
    depends_on:
    - backend
    ports:
    - "8080:8080"
    - "1936:1936"
    environment:
      FRONTEND_PORT: "8080"
      BACKENDS: "backend"
      BACKENDS_PORT: "8080"
      DNS_ENABLED: "True"
      HTTPCHK: "GET /"
      INTER: "5s"
      LOG_LEVEL: "info"

  backend:
    image: plone/plone-backend:6.0.0b2
    restart: always
    environment:
      ZEO_ADDRESS: zeo:8100
    ports:
    - "8080"
    depends_on:
      - zeo

  zeo:
    image: plone/plone-zeo:latest
    restart: always
    volumes:
      - data:/data
    ports:
    - "8100"

volumes:
  data: {}

Build the project with multiple backends#

Run docker compose up -d --scale backend=4 from your project directory.

Access Plone via Browser#

Point your browser at http://localhost:8080. Login using the username and password combination of admin and admin. You should see the default Plone site creation page.

Access HAProxy Stats Page via Browser#

Point your browser at http://localhost:1936. Login using the username and password combination of admin and admin. You should see HAProxy statistics for your Plone cluster.

Shutdown and cleanup#

The command docker compose down removes the containers and default network, but preserves the Plone database.

The command docker compose down --volumes removes the containers, default network, and the Plone database.