How to configure a keycloak cluster properly (legacy Wildfly edition)

_keycloak-cluster-config.md

Keycloak Cluster Configuration (How to) - Legacy Wildfly Distribution!!!

This is a short and simple example on how to build a proper Keycloak cluster, using JDBC_PING as discovery protocol and an NGINX server as reverse proxy.

Please see also my video about Keycloak Clustering: http://www.youtube.com/watch?v=P96VQkBBNxU

docker-compose-cluster.yml

version: '3'

services:
  postgres:
    container_name: kc_db
    image: postgres:latest
    environment:
      POSTGRES_USER: keycloak
      POSTGRES_PASSWORD: password
    ports:
      - 5432:5432

  kc1:
    container_name: kc1
    image: quay.io/keycloak/keycloak:17.0.0-legacy
    environment:
      DB_VENDOR: postgres
      DB_ADDR: postgres
      KEYCLOAK_FRONTEND_URL: "http://localhost:8000/auth/"
      KEYCLOAK_USER: admin
      KEYCLOAK_PASSWORD: admin
      PROXY_ADDRESS_FORWARDING: "true"
      CACHE_OWNERS_COUNT: 2
      CACHE_OWNERS_AUTH_SESSIONS_COUNT: 2
      JGROUPS_DISCOVERY_PROTOCOL: JDBC_PING
      JGROUPS_DISCOVERY_PROPERTIES: "datasource_jndi_name=java:jboss/datasources/KeycloakDS,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))\",remove_all_data_on_view_change=true"
    depends_on:
      - postgres

  kc2:
    container_name: kc2
    image: quay.io/keycloak/keycloak:latest
    environment:
      DB_VENDOR: postgres
      DB_ADDR: postgres
      KEYCLOAK_FRONTEND_URL: "http://localhost:8000/auth/"
      PROXY_ADDRESS_FORWARDING: "true"
      CACHE_OWNERS_COUNT: 2
      CACHE_OWNERS_AUTH_SESSIONS_COUNT: 2
      JGROUPS_DISCOVERY_PROTOCOL: JDBC_PING
      JGROUPS_DISCOVERY_PROPERTIES: "datasource_jndi_name=java:jboss/datasources/KeycloakDS,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))\",remove_all_data_on_view_change=true"
    depends_on:
      - postgres

  lb:
    container_name: kc_lb
    image: nginx:alpine
    volumes:
      - ${PWD}/nginx.conf:/etc/nginx/conf.d/default.conf
    ports:
      - "8000:8000"
    depends_on:
      - kc1
      - kc2

nginx.conf

upstream backend {
    server kc1:8080 fail_timeout=2s;
    server kc2:8080 fail_timeout=2s;
}

server {
    listen       8000;
    server_name  localhost;

    location / {
        proxy_set_header    Host               $host;
        proxy_set_header    X-Real-IP          $remote_addr;
        proxy_set_header    X-Forwarded-For    $proxy_add_x_forwarded_for;
        proxy_set_header    X-Forwarded-Host   $host;
        proxy_set_header    X-Forwarded-Server $host;
        proxy_set_header    X-Forwarded-Port   $server_port;
        proxy_set_header    X-Forwarded-Proto  $scheme;

        proxy_pass              http://backend;
        proxy_connect_timeout   2s;

        proxy_buffer_size          128k;
        proxy_buffers              4 256k;
        proxy_busy_buffers_size    256k;
    }
}