Starting with Puma 6.0, the --daemon flag has been removed for security reasons. Puma no longer supports daemonizing itself directly. If you need to run Puma in the background as a service, you should use a process manager like systemd, Upstart, or foreman, instead of using --daemon.
Instead of using Puma’s built-in daemon mode, you can manage it with a process manager like systemd. Here’s an example of how you can set up Puma with systemd:
Create a file called /etc/systemd/system/puma.service with the following content (replace paths with your specific setup):
[Unit]