On Tue, Sep 01, 2020 at 07:50:46AM +0800, Ed Greshko wrote:
I don't think the DHCP server for the QEMU VMs is supplying a domain. However, Network Manager will add a "search" option to resolv.conf when "hostname" returns a FQDN.
Ed opened https://bugzilla.redhat.com/show_bug.cgi?id=1874419. To follow up on this from a slightly different perspective:
NM *does* support pushing "search domains" into systemd-resolved, and in general this is expected to work. For example, I now have a company VPN configured using NM, and the "redhat.com" search domain is active:
$ resolvectl status tun0 Link 35 (tun0) Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 ... Current DNS Server: 10.38.5.26 DNS Servers: 10.45.248.15 10.38.5.26 DNS Domain: redhat.com
$ resolvectl query www www.redhat.com www: 23.211.151.51 -- link: hub0 2a02:26f0:1300:186::d44 -- link: hub0 2a02:26f0:1300:190::d44 -- link: hub0 (e3396.dscx.akamaiedge.net)
-- Information acquired via protocol DNS in 263.0ms. -- Data is authenticated: no www.redhat.com: 2a02:26f0:1300:190::d44 -- link: hub0 2a02:26f0:1300:186::d44 -- link: hub0 23.211.151.51 -- link: hub0 (e3396.dscx.akamaiedge.net)
-- Information acquired via protocol DNS in 2.4ms. -- Data is authenticated: no
(It says "hub0" because the address is public, so it would not be routed through tun0. The relevant part is that "www" gets treated as "www.redhat.com" by resolved.)
What does *not* happen, is the domainname part of a hostname received via DHCP being installed as a search domain. In the case of a lease received via DHCP by NetworkManager, it's NetworkManager that decides what config to push to resolved. As discussed in https://bugzilla.redhat.com/show_bug.cgi?id=1874419, automatically installing the domain name as search domain this is not expected and probably not a good idea as a default.
Zbyszek