Systemd and containers

Posted Jun 11, 2015 17:33 UTC (Thu) by kleptog (subscriber, #1183)
In reply to: Systemd and containers by gfa
Parent article: Systemd and containers

I think you misunderstood. The active connections in this case are for example a VPN to your work and a VPN to your Uni. So when asked to resolve a domain resolved asks each of the upstream nameservers (at your work and at Uni) and merges the results. I don't think dnsmasq can do that and your example certainly doesn't (it sends everything to 8.8.8.8).

Systemd and containers

Posted Jun 11, 2015 18:00 UTC (Thu) by cuviper (subscriber, #56273) [Link] (5 responses)

You can do split networks with dnsmasq though, as NetworkManager will do with the dnsmasq plugin. For example I get a something like "dnsmasq --server=/redhat.com/$VPN_DNS --server=$ISP_DNS", so all redhat.com queries go over the VPN, and the rest go to my ISP. That seems better than "ask everyone and merge" that you describe.

Systemd and containers

Posted Jun 11, 2015 22:42 UTC (Thu) by rahvin (guest, #16953) [Link] (4 responses)

The method you describe would require that you configure every time you change connection what connections go over what links. This can become exceedingly micromanaging and drive someone nuts. The systemd method ensures that you always get the results regardless of what links are up or active. As long as names don't overlap that is, if you have overlaps in names the systemd method would be a resolv nightmare.

Systemd and containers

Posted Jun 11, 2015 22:45 UTC (Thu) by cuviper (subscriber, #56273) [Link] (3 responses)

Yeah, it's not something I'd want to configure manually, but NetworkManager does it for me.

Systemd and containers

Posted Jun 12, 2015 8:16 UTC (Fri) by anselm (subscriber, #2796) [Link] (2 responses)

NetworkManager is a useful but quite complicated piece of software, and adding potentially several instances of dnsmasq into the mix isn't going to make things more straightforward. It would be useful to be able to deal with as many of the standard use cases as is reasonable with systemd-networkd (and if it plays well with containers, so much the better) and reserve the extra complexity of NetworkManager for those situations where it is actually needed (like dealing with lots of different wireless networks).

Systemd and containers

Posted Jun 18, 2015 8:07 UTC (Thu) by dakas (guest, #88146) [Link] (1 responses)

NetworkManager is a useful but quite complicated piece of software,

So does systemd differ by being not useful or by being not complicated? I don't quite see the point you try to make against this being NIH syndrome.

Systemd and containers

Posted Jun 18, 2015 9:08 UTC (Thu) by anselm (subscriber, #2796) [Link]

There are lots of systems that profit from being based on systemd but have no conceivable need for NetworkManager (mostly because NetworkManager's strength is dealing with a changing network environment, while these systems may be sitting firmly on a desk or in a rack somewhere). It makes sense to investigate whether such systems could use something simpler than NetworkManager+dnsmasq.