[systemd-devel] daemon-reload does not pick up changes to /etc/systemd/system during boot

[Andrei Borzenkov]

On 12.10.2022 23:54, Alex Aminoff wrote:
> 
> I am diskless booting Rocky Linux 9 , using an NFS mounted root. This
> works OK so far. However, I want to mount /etc/ as a tmpfs and load up a
> bunch of config files, then have systemd see the (new)
> /etc/systemd/system and use that in the rest of the boot process,
> bringing up some non-default services etc.
> 
> I have a service that does the creation and copying of /etc which runs
> from local-fs-pre.target.wants:
> 
> $ cat nber-rc-initdiskless.service
> 
> [Unit]
> Description=Run NBER diskless setup including /sbin/copy_conf
> DefaultDependencies=no
> Before=local-fs-pre.target
> After=initrd-switch-root.service plymouth-switch-root.service
> OnFailure=emergency.target
> OnFailureJobMode=replace-irreversibly
> AssertPathExists=/etc/rc.initdiskless
> 
> [Service]
> Type=oneshot
> RemainAfterExit=yes
> ExecStart=/usr/bin/bash /etc/rc.initdiskless
> ExecStart=systemctl daemon-reload
> StandardOutput=journal+console
> StandardError=journal+console
> 
> [Install]
> WantedBy=local-fs-pre.target
> 
> I then have for example
> /etc/systemd/system/multi-user.target.wants/autofs.service ->
> /usr/lib/systemd/system/autofs.service
> 
> As soon as the system is up I can ssh in and run systemctl start autofs
> and it works just fine. In journalctl -b I can see my rc.initdiskless
> running followed by the daemon-reload. But no autofs and no evidence
> that systemd tried to start autofs.
> 
> My only guess is that somehow daemon-reload is not enough because as far
> as systemd is concerned we already queued up for starting all the
> services needed by multi-user.target back when we switched root from the
> initrd.
> 

Correct.

> Hopefully it is something obvious that I am missing.

No. See also thread

https://lists.freedesktop.org/archives/systemd-devel/2022-September/048370.html