Bug#1079819: systemd-resolved: Feed DNS information from network-manager in postinst

[Luca Boccassi]

Control: tags -1 unreproducible

On Tue, 27 Aug 2024 12:03:29 -0700 Sunil Mohan Adapa <sunil at medhas.org>
wrote:
> Package: systemd-resolved
> Severity: wishlist
> 
> Dear Maintainer,
> 
> Currently, when systemd-resolved is installed on systems with
network-manager,
> DNS resolution stops working until a reboot (or until NM brings down
and up a
> connection with global DNS). This is because 1) systemd-resolved
package
> correctly sets a link from /etc/resolv.conf to
/run/systemd/resolve/stub-
> resolv.conf 2) Currently known DNS servers at the time of package
installation
> are not loaded into systemd-resolved and 3) Understandably, Debian
has removed
> fallback DNS servers in systemd-resolved (using --dns-server=''). In
case
> systemd-networkd is the network configuration tool instead of
network-manager,
> systemd-resolved will pickup DNS servers from .network configuration
files (and
> possibly from DNS servers known to systemd-networkd via DHCP?).
> 
> On desktops and mobiles where network-manager is common, this
experience can be
> improved by loading DNS servers and search domains known to network-
manager
> (static or obtained from DHCP) into systemd-resolved. Postinst script
ought to
> do something like:
> 
> if [ -d /run/NetworkManager ]; then
>     nmcli general reload dns-rc
> fi
> 
> FreedomBox is switching to systemd-resolved from resolvconf. These
machines
> shall automatically upgrade and can't become unreachable over network
or
> request user intervention. Reboots, when necessary, can only be done
once a day
> at a fixed time. We are running 'reload dns-rc' after installing
systemd-
> resolved. This change will also help if/when systemd-resolved becomes
default
> in Debian and users upgrade from a stable release to the next.
> 
> Thank you for maintaining systemd packaging,

Hi, I cannot reproduce this issue. If I remove resolved and reinstall
it, it gets the data from network-manager just fine. How did you
reproduce the issue precisely?