Comment 10 for bug 1745463

I quite agree with @GeekSmith here. We disabled systemd-resolved on bionic and install ifupdown instead since we install this on server that have a static configuration and we don't want systemd-resolved to modify anything in the resolv.conf file.

Only during the initial installation time of the server we use dhclient to get an IP address. The result is that the resolv.conf file is not modified by dhclient despite systemd-resolved being disabled. To work around this issue, we simply deleted the /etc/dhcp/dhclient-enter-hooks.d/resolved file as we don't need it anyway.

A cleaner way of course it to actually test in the file if systemd-resolved is used, as @GeekSmith's patch does.