remove hardcoded DNS servers

[furlongm]

First pass at removing hardcoded DNS servers so these boxes can use the DHCP-supplied DNS server.

Closes #54

[ladar]

Leaving this open for now. I'll need to do some testing before merging.

I assume these changes mean the boxes won't work if they don't get a DNS server via DHCP?

Any idea how we can setup fall back resolvers?

[furlongm]

The boxes won't have working DNS if they don't get a DNS server via DHCP.

For systemd-enabled systems with resolved, fallback resolvers can be specified in /etc/systemd/resolved.conf:

e.g.

FallbackDNS=1.1.1.1

[ladar]

I've tried using this, and it caused a number of the box creation configs to fail, particularly on Hyper-V. Setting a FALLBACK also caused problems on the boxes I tried it with.

I'm still traveling, so part of the problem could have been the crappy hotel DNS servers. I plan to play with this more when I get a Windows built bot setup at the datacenter.

I'm also hoping that when I finally get the robox blade servers online it will be easier to test out changes like this across all the different box/distro/platform combinations.

Long story short, this request isn't dead, just pending further research.

[Pesa]

@ladar any updates?

[Jasper-Ben]

Also interested in a fix. We just ran into this issue with a split DNS setup.