Just wanted to let you know that I build a small example [0] that 

demonstrates the usage of Keycloak with mod_auth_oidc [1] 

with Docker + Apache + PHP.

Works like a charm :)

Cheers,

Thomas

[0] https://github.com/thomasdarimont/keycloak_mod_auth_oidc_example

[1] https://github.com/pingidentity/mod_auth_openidc