Hello Stéphane, to conclude the lose end of this thread..
Stéphane Graber [2016-05-31 15:52 -0400]: > > > 1) Does resolved now support split DNS support? > > > That is, can Network Manager instruct it that only *.example.com > > > should be sent to the DNS servers provided by a given VPN? > > > > resolved has a D-Bus API SetLinkDomains(), similar in spirit to > > dnsmasq. However, NM does not yet know about this, and only indirectly > > talks to resolved via writing /etc/resolv.conf (again indirectly via > > resolvconf). So the functionality on the resolved is there, but we > > don't use it yet. This is being tracked in the blueprint. > > Ok and does it support configuring this per-domain thing through > configuration files? > > That's needed so that LXC, LXD, libvirt, ... can ship a file defining a > domain for their bridge which is then forwarded to their dnsmasq > instance. In my other reply I said that resolved doesn't have this kind of fine-grained configuration files, as it mostly expects network management software to tell it about these things. But what you *can* do is to use networkd for this: $ cat /lib/systemd/network/lxdbr0.network [Match] Name=lxdbr0 [Network] DNS=127.0.0.1 Domains= ~lxd With this, networkd won't actually set up the bridge (as there is no DCHP=, Address=, corresponding .netdev etc.), but as soon as it comes up via auto-activation of lxd-bridge.service, it will poke that information into resolved (via the above SetLinkDomains() call). I just tested that in a VM, and it does what you expect. The main drawback is that you need to start systemd-networkd.service for this (at least as a Requires= of lxd-bridge.service). Now, on server/cloud we want to move to networkd anyway, but on a desktop we'd usually only have NetworkManager running. So this overhead would mainly be justified if you would consider replacing lxd-bridge.service by a "full" networkd config, i. e. let the above file actually set up and configure the full bridge (But this doesn't go that well with the existing /etc/default/lxd-bridge format). If using a configuration *file* is not a tight requirement, but you only actually care about this working OOTB, then a less intrusive approach might be to just add a dbus-send/gdbus/busctl ExecStartPost= to lxd-bridge.service that does the SetLinkDomains() call. I initially thought about lxd just dropping a resolvconf hook, but that doesn't work I think: /etc/resolv.conf has no syntax for domain-specific DNS servers, so we need to use a richer API like dnsmasq or resolved for these. Would either approach work for you, or do we need something different? Thanks, Martin -- Martin Pitt | http://www.piware.de Ubuntu Developer (www.ubuntu.com) | Debian Developer (www.debian.org)
signature.asc
Description: PGP signature
-- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
