docker-stack.yml

#
# https://github.com/SeleniumHQ/docker-selenium/blob/trunk/docker-compose-v3-swarm.yml
#
# cluster:
# - manger: 1  (4vCPU, 4GiB MEM)
# - worker: 10 (8vCPU, 8GiB MEM)
#

version: '3.8'

services:

  hub:
    image: selenium/hub:4
    ports:
      - "4442:4442"
      - "4443:4443"
      - "4444:4444"
    deploy:
      replicas: 1
      placement:
        constraints:
          - node.role == manager
      restart_policy:
        condition: on-failure

  chrome:
    image: selenium/node-chrome:4
    entrypoint: bash -c 'SE_OPTS="--host $$HOSTNAME" /opt/bin/entry_point.sh'
    volumes:
      - type: tmpfs
        target: /dev/shm
        tmpfs:
          size: 2147483648 # numfmt --from=iec 2G
    environment:
      - SE_EVENT_BUS_HOST=hub
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443
      - SE_NODE_OVERRIDE_MAX_SESSIONS=true
      - SE_NODE_MAX_SESSIONS=8
      - SE_NODE_SESSION_TIMEOUT=180
      - START_XVFB=true
      - VNC_NO_PASSWORD=1
      - VNC_VIEW_ONLY=1
    depends_on:
      - hub
    deploy:
      replicas: 10
      placement:
        max_replicas_per_node: 1
        constraints:
          - node.role == worker
      restart_policy:
        condition: on-failure

networks:
  default:
    ipam:
      config:
        - subnet: 192.168.100.0/24