Use variables in scripts to ease secret externalisation
Use variables for all templated values (just like in templates/scripts/init-keycloak
file).
I will also open the possible externalisation of secrets management. Indeed, it would be easy to replace all lines defining a variable with a hardcoded secret by a call to an external tools that will provide the secret at runtime.
For example, replacing:
clientSecret="mybestsecret"
by
clientSecret=$(get_secret_for(nextcloud, keycloackSecret))