When automating WildFly server builds using tools like Puppet, Chef, or Ansible, customization of configuration files such as standalone.xml, domain.xml, host.xml, and host-slave.xml is crucial. Two primary methods exist: directly editing these XML files or utilizing the WildFly CLI. Direct XML editing is straightforward and does not require a running WildFly instance, but it risks overwriting runtime changes and complicates version upgrades. In contrast, the CLI approach, although more complex and requiring a running instance, offers idempotency and ease of upgrade across WildFly versions. CLI scripts allow targeted changes with immediate error feedback and can be adapted for complex environments using Java libraries. Despite each method's benefits and drawbacks, the choice depends on the specific requirements for idempotency and ease of use, with CLI scripts favored for idempotency and XML editing for simplicity.