Template creates a volume for PostgreSQL and boots up Keycloak connected to it. Traefik is used like load balancer to redirect all request to diferent container instances. The most important change is the JGroups Discovery protocol that is used in this configuration, which is `JDBC_PING`. `JDBC_PING` reuses the same database instance as all Keyc…

keycloak-postgres-jdbc-ping.yml

version: '3'

volumes:
  postgres_data:
    driver: local

services:
  postgres:
    image: 'postgres:alpine'
    volumes:
      - ./postgres:/var/lib/postgresql/data
    restart: 'always'
    # ports:
    #   - 5432:5432
    environment:
      POSTGRES_USER: keycloak
      POSTGRES_PASSWORD: password
      POSTGRES_DB: keycloak
      POSTGRES_HOST: postgres

  traefik:
    image: library/traefik:alpine
    container_name: traefik
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    command: >
      --logLevel=ERROR
      --api.dashboard
      --docker
      --entrypoints="Name:http Address::80"
      --defaultentrypoints="http"
    ports:
      - 80:80
      - 3000:8080

  keycloak:
    image: jboss/keycloak
    environment:
      DB_VENDOR: postgres
      DB_ADDR: postgres
      DB_PORT: 5432
      DB_DATABASE: keycloak
      DB_USER: keycloak
      DB_PASSWORD: password
      KEYCLOAK_USER: admin
      KEYCLOAK_PASSWORD: Pa55w0rd
      # KEYCLOAK_LOGLEVEL: DEBUG
      JGROUPS_DISCOVERY_PROTOCOL: JDBC_PING
      JGROUPS_DISCOVERY_PROPERTIES: datasource_jndi_name=java:jboss/datasources/KeycloakDS,info_writer_sleep_time=500,initialize_sql="CREATE TABLE IF NOT EXISTS JGROUPSPING ( own_addr varchar(200) NOT NULL, cluster_name varchar(200) NOT NULL, created timestamp default current_timestamp, ping_data BYTEA, constraint PK_JGROUPSPING PRIMARY KEY (own_addr, cluster_name))"
    depends_on:
      - postgres
    labels:
      traefik.enable: true
      traefik.port: 8080
      traefik.protocol: http
      traefik.frontend.rule: Host:localhost
      traefik.frontend.passHostHeader: true
      # traefik.backend.loadbalancer.stickiness: true