What complicates matters is that you’ve not said what features are enabled on Foreman - it can manage PuppetCA, DHCP, DNS, and TFTP, or just a subset of these - and of course expectations depend on configuration.
Assuming a complete configuration of controlling everything, then I would expect click “Build” to cause just the changes to PXE file, but that’s because alll the other stuff is done at host creation time. If this were a brand new host, you’d see:
A DHCP reservation created for the MAC/IP combination
A DNS A-record and PTR-record created for the IP/name combination
A PXElinux config file created for the MAC
This would mean that when the host boots for the first time, it can get an IP from the DHCP server, and be told where the TFTP server is (‘nextserver’ option in the lease). It then queries said IP for TFTP/PXE, and is given a PXE file, which it then uses to load an initrd/kernel over the network.
Again, I’m desribing generics here, for example if your provisioning network has not got Foreman managing DHCP, then you’d be responsible for ensuring the leases give out the right nextserver IP, and so forth.
This is host creation rather than just flipping the Build flag, but you get the idea - here you see it creating a DHCP lease, creating the PXElinux cfg files, and checking if the initrd/vmlinuz files need downloading to the proxy. This is the kind of output you’re looking for in production.log. I encourage you to read that thread as there are other log examples they may help you make sense of what you’re seeing, since you can’t share it for us to see.
To answer your question, yes, you’d only expect to see the button change from Build to Cancel Build in the UI - the rest happens behind the scenes. You’d then go reboot the server at your leisure, and it should pick up the changed PXElinux cfg file.
