systemd-resolved.service is active after initrd about mkinitcpio-systemd-tool

[Andrei-Pozolotin]

1. RE: a lot of things around DNS resolution

• Requires=systemd-resolved.service is used (historically) to help with initial setup / network config debug

2. RE: the service keep running even after initrd

• initrd-network.service (and its hard dependencies) should not be enabled outside of initrd mode due to ConditionPathExists=/etc/initrd-release stanza

• this is likely an issue specific to your setup, please try to trace dependencies more carefully

• for example, one could use systemd-analyze:
  https://www.freedesktop.org/software/systemd/man/systemd-analyze.html

systemd-analyze dot systemd-resolved* | dot -T png > systemd-resolved.png

systemd-analyze dot initrd* | dot -T png > systemd-total.png

systemd-analyze dot --order initrd* | dot -T png > systemd-order.png

systemd-analyze dot --require initrd* | dot -T png > systemd-require.png

[ArchangeGabriel]

Not sure if I was clear, but resolved is started during initrd, and never stopped. Anyway, here are the pictures.

[Andrei-Pozolotin]

resolved is started during initrd, and never stopped

ok, then:

• if you comment out Requires=systemd-resolved.service in initrd-network.service
• is systemd-resolved.service still active after initrd?

[ArchangeGabriel]

If I comment out this line, systemd-resolved is never started, and thus is not active after initrd (nor during it).

[Andrei-Pozolotin]

ok, thinking

[Andrei-Pozolotin]

please verify the following workaround:
https://www.freedesktop.org/software/systemd/man/systemd.unit.html#StopWhenUnneeded=

1. create service overrides

/etc/systemd/system/systemd-networkd.service.d/override.conf

[Unit]
StopWhenUnneeded=yes

/etc/systemd/system/systemd-resolved.service.d/override.conf

[Unit]
StopWhenUnneeded=yes

2. remove service autostart

systemctl disable systemd-networkd.service
systemctl disable systemd-resolved.service

3. refresh service cache

systemctl daemon-reload

4. perform image rebuild and system reboot

mkinitcpio -p linux
systemctl reboot

5. confirm that both services are active during initrd and inactive during rootfs

[Andrei-Pozolotin]

there seems no elegant way to make this any more simple,
so will treat this use case and the workaround as a "feature" not a "bug"

[MahouShoujoMivutilde]

The workaround works fine, thanks.

[ArchangeGabriel]

Sorry for the long delay (for some reason both unbound and systemd-resolved were binding to :53 without issue, so my system happened to work even if I did not take care of this, but after recently upgrading with the tinyssh key changes I’ve remembered about this issue), but indeed the workaround works fine, and since I’m using systemd-networkd I’ve only add the override for systemd-resolved, and that was enough. Maybe this should be documented then?