DNS resolution broke after upgrading to 18.04, resolvconf broken or not fully installed

Question

when googling i find stuff like this: askubuntu resolvconf

but /etc/resolv.conf doesn't seem to exist

sudo dpkg-reconfigure resolvconf

returns that resolvconf is broken or not fully installed

heard 18.04 might be using netplan instead now, but /etc/netplan seems to be completely empty

not sure what to do now, any help would be appreciated

EDIT: running sudo apt install resolvconf asks me to remove openresolv, whatever that is, not sure if i should do that :/

EDIT: /etc/network/interfaces is completely empty aside from loopback interface, can still ping IP addresses tho

How did you perform this upgrade? - upgrading should not remove resolvconf. - upgrading should not install openresolv, which is an alternative implementation that has never been supported by Ubuntu. - upgrading should install the netplan package but will not remove ifupdown. - upgrading using any supported method does NOT delete configuration from /etc/network/interfaces. — slangasek, Sep 17 '18 at 05:46
The short answer should be "you don't need resolvconf on 18.04, /etc/resolv.conf is a symlink to systemd-resolved instead". But it sounds like you have several other things going wrong with your system. — slangasek, Sep 17 '18 at 05:50
seems like resolvconf was broken, not sure how or why, but reinstalling it manually seems to have fixed it — user301538, Sep 17 '18 at 16:15

score 2 · Accepted Answer · answered Sep 17 '18 at 16:15

If someone encounters a similar issue, here's how i fixed it

transfer to Ubuntu PC using USB

sudo apt purge resolvconf
sudo apt install ./resolvconf_1.79ubuntu10_all.deb
sudo dpkg --reconfigure resolvconf
reboot

and then it should be fixed

1 Answers1