TUMBLEWEED Ordering cycle at boot with nss-lookup: named fails to start initially; workaround: manually `rcnamed start`

I have seen this on one Raspberry Pi 3 system: named failing to start during a normal reboot.

The solution is to manually rcnamed start as root after boot.

From [Wayback] TUMBLEWEED Ordering cycle at boot with nss-lookup, the rcnamed status is the same as on my system, but no solution in that thread:

# systemctl status named
● named.service - Berkeley Internet Name Domain (DNS)
     Loaded: loaded (/usr/lib/systemd/system/named.service; enabled; vendor preset: disabled)
     Active: inactive (dead) Jul 02 08:13:40 hpprol2 systemd[1]: nss-lookup.target: Found ordering cycle on named.service/start
Jul 02 08:13:40 hpprol2 systemd[1]: nss-lookup.target: Found dependency on time-sync.target/start
Jul 02 08:13:40 hpprol2 systemd[1]: nss-lookup.target: Found dependency on ntpd.service/start
Jul 02 08:13:40 hpprol2 systemd[1]: nss-lookup.target: Found dependency on nss-lookup.target/start
Jul 02 08:13:40 hpprol2 systemd[1]: nss-lookup.target: Job named.service/start deleted to break ordering cycle starting with nss-lookup.target/start

Apparently, sometimes there is a service startup dependency loop, and named becomes the victim of it, effectively rendering DNS inoperable.

My system was running this version of Tumbleweed:

statler:~ # cat /etc/SUSE-brand /etc/os-release 
openSUSE
VERSION = tumbleweed
NAME="openSUSE Tumbleweed"
# VERSION="20200825"
ID="opensuse-tumbleweed"
ID_LIKE="opensuse suse"
VERSION_ID="20200825"
PRETTY_NAME="openSUSE Tumbleweed"
ANSI_COLOR="0;32"
CPE_NAME="cpe:/o:opensuse:tumbleweed:20200825"
BUG_REPORT_URL="https://bugs.opensuse.org"
HOME_URL="https://www.opensuse.org/"
LOGO="distributor-logo"

On an identical system, the boot just worked fine, so it might be timing related.

waldorf:~ # cat /etc/SUSE-brand /etc/os-release 
openSUSE
VERSION = tumbleweed
NAME="openSUSE Tumbleweed"
# VERSION="20200825"
ID="opensuse-tumbleweed"
ID_LIKE="opensuse suse"
VERSION_ID="20200825"
PRETTY_NAME="openSUSE Tumbleweed"
ANSI_COLOR="0;32"
CPE_NAME="cpe:/o:opensuse:tumbleweed:20200825"
BUG_REPORT_URL="https://bugs.opensuse.org"
HOME_URL="https://www.opensuse.org/"
LOGO="distributor-logo"

It has been fixed late January 2021 as per [Wayback] Bug 1177491 – systemd ordering cycle with nss-lookup.target:

Josef Möllers 2021-01-27 15:50:15 UTC

Fixed by removing "Before=nss-lookup.target" from systemd's service file.

It means editing /etc/systemd/system/multi-user.target.wants/named.service from

[Unit]
Description=Berkeley Internet Name Domain (DNS)
After=network.target
After=time-sync.target
Before=nss-lookup.target
Wants=nss-lookup.target
Wants=time-sync.target

[Service]
Type=forking
ExecStart=/usr/sbin/named.init start
ExecReload=/usr/sbin/named.init reload
ExecStop=/usr/sbin/named.init stop

[Install]
WantedBy=multi-user.target

into

[Unit]
Description=Berkeley Internet Name Domain (DNS)
After=network.target
After=time-sync.target
Wants=nss-lookup.target
Wants=time-sync.target

[Service]
Type=forking
ExecStart=/usr/sbin/named.init start
ExecReload=/usr/sbin/named.init reload
ExecStop=/usr/sbin/named.init stop

[Install]
WantedBy=multi-user.target

Note that it is an alias, so it won’t show up in a versioned /etc directory (for instance using etckeeper):

# ls -Alh /etc/systemd/system/multi-user.target.wants/named.service 
lrwxrwxrwx 1 root root 37 Sep  5  2020 /etc/systemd/system/multi-user.target.wants/named.service -> /usr/lib/systemd/system/named.service

–jeroen