Ubuntu HPC DNS setup on compute node

To configure correct DNS settings on compute node use:

First test DNS resolution via master using:

nslookup node<n>.<private-zone> <master-private-ip>

Then configure appropriate DNS and search domain using:

resolvectl domain <private-interface> <private-zone>
resolvectl dns <private-interface> <master-private-ip>

Test by using:
```
ping master
ping node<n>
```
Resolvectl based settings don't persist after reboot. For persistent settings launch following as root user:
```
sudo nm-connection-editor
```
and change appropriate interface DNS and search settings using the editor.
Optionally, Reboot the node and validate DNS and domain settings are coming properly after reboot.

Anonymous