The "set service ssh listen-address" command only accepts IPv4 or IPv6 addresses as arguments but if the given interface is getting it's address from DHCP, this address is unknown as it can and will change over time. Other commands accept an interface for these cases so it would be fantastic if we could do this...
set service ssh listen-address eth0
... and have eth0 translated to the provisioned address at runtime (and update sshd_config, restart sshd, etc. whenever the IP address changes via dhcpc hooks/systemd/etc.).
I'm opening this as a feature request but IMHO this is a gap in Crux that prevents VyOS from being fully utilized with DHCP interfaces. Thanks!