Comment 2 for bug 1646585

I have tested this several times with different network settings and can see that ubiquity plays quite nicely with resolvconf. That includes static (e.g. dns-nameservers entries in /e/n/interfaces) and dhcp cases.

The only problem is the issue identified by Newton Liu above - the resolv.conf gets unlinked. Hence, the correct entries (as present in /run/resolvconf/resolv.conf) are invisible in the system.