Replacing the background of keycloak login screen in docker / docker-compose

So. You want to replace the default background of the login-screen in a docker-image in docker-compose?

Just mount a new image on the existing background 😉

keycloak:
image: quay.io/keycloak/keycloak:13.0.0
environment:
- KEYCLOAK_USER=admin
- KEYCLOAK_PASSWORD=superdupersecret
- DB_VENDOR=h2
- PROXY_ADDRESS_FORWARDING=true
volumes:
- ./keycloak-data:/opt/jboss/keycloak/standalone/data
- ./my-custom-image.png:/opt/jboss/keycloak/themes/keycloak/login/resources/img/keycloak-bg.png