For docker-compose add a comment to include the :Z flag to avoid SELinux issues with running containers

[ggyaxxx]

Description

When running the Infinispan server via Docker on any SELinux-enabled system, the mounted configuration file is not accessible due to SELinux restrictions. This results in a Permission denied error.

Steps to Reproduce

1. Use the following docker-compose.yaml:

   version: "3"
   services:
     infinispan-tracing:
       image: quay.io/infinispan/server:15.1
       volumes:
         - ./infinispan-tracing-configuration-server.yaml:/user-config/infinispan-tracing-configuration-server.yaml
   

2. Run the docker-compose up command and notice the error
   java.io.FileNotFoundException: /user-config/infinispan-tracing-configuration-server.yaml (Permission denied)

Steps to Fix

Adding :Z to the volume declaration in docker-compose.yaml allows SELinux to label the file correctly:

volumes: - ./infinispan-tracing-configuration-server.yaml:/user-config/infinispan-tracing-configuration-server.yaml:Z

Because the :Z flag may cause errors on other systems though, simply adding a comment to the docker-compose file could save users a bit of time of troubleshooting.