DNS provisioning mostly works out of the box. But once for a cloud instance the DNS resolver had terrible response times. So I added another resolver.
Ubuntu uses netplan as abstraction layer for network config.
sudo nano /etc/netplan/01-netcfg.yaml
...
nameservers:
search: [ invalid ]
addresses:
- 127.0.0.1 # the new resolver
- 123.123.123.1 # provided dns resolver
- 223.123.123.2 # provided dns resolver
For a containerized DNS resolver see here.
DNS resolvers should NOT be exposed to public networks (dns amplification attacks etc.)! So make sure to bind the dns server socket to localhost or the local network.
Finally, run: sudo netplan apply
Check which DNS resolver is currently in use: sudo resolvectl status eth0 (filter for network interface eth0 is optional)
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