Extension of jboss/keycloak-ha-postgres official image which don't rely on UDP (multicast) for clustering but instead use TCP (unicast). Useful for orchestators which does not support multicast between distinct hosts like Docker Swarm or Cattle
First start a PostgreSQL instance using the PostgreSQL docker image:
docker run --name postgres -e POSTGRES_DATABASE=keycloak -e POSTGRES_USER=keycloak -e POSTGRES_PASSWORD=keycloak -e POSTGRES_ROOT_PASSWORD=password -d postgres
Start one Keycloak instance that form a cluster and connect to the PostgreSQL instance running in previously started 'postgres' container:
docker run --name keycloak1 -p 8081:8080 --link postgres:postgres -e KEYCLOAK_USER=keycloak -e KEYCLOAK_PASSWORD=keycloak -e POSTGRES_DATABASE=keycloak -e POSTGRES_USER=keycloak -e POSTGRES_PASSWORD=keycloak shelbert/keycloak-ha-postgres-no-udp
Browse to http://localhost:8081 to connect to the first instance (log in : keycloak/keycloak).
Start more Keycloak instances that form a cluster with the first one :
docker run --name keycloak2 -p 8082:8080 --link keycloak1:keycloak1 --link postgres:postgres -e KEYCLOAK_USER=keycloak -e KEYCLOAK_PASSWORD=keycloak -e POSTGRES_DATABASE=keycloak -e POSTGRES_USER=keycloak -e POSTGRES_PASSWORD=keycloak -e JGROUPS_TCPPING_INITIAL_HOSTS=keycloak1[7600] shelbert/keycloak-ha-postgres-no-udp
Browse to http://localhost:8082 and check that changes in first instance are visible from the second one and vice versa.
Optional. Cluster nodes in the form <host1>[7600],<host1>[7600],<host3>[7600] for example : keycloak1[7600],keycloak2[7600],keycloak3[7600]