On Fr, 16.09.22 10:10, Antonio Murdaca (run...@redhat.com) wrote: > Hi, following > https://systemd.io/AUTOMATIC_BOOT_ASSESSMENT/#how-to-adapt-this-scheme-to-other-setups > I've been experimenting on a fedora system > with systemd-boot-check-no-failures.service and the ability to have > services run "after" boot-complete.target. The basic use case would just to > have something that checks services are up and running, reach boot-complete > if they are, and start other services afterwards. > I've taken from that blog this piece specifically: > ``` > To support additional components that shall only run on boot success, > simply wrap them in a unit and order them after boot-complete.target, > pulling it in. > ``` > So I've done the following with an example service and by enabling : > > # cat /etc/systemd/system/test.service > [Unit] > Description="Order after boot-complete.target, pulling it in" > After=boot-complete.target > Requires=boot-complete.target > > [Service] > Type=oneshot > ExecStart=/usr/bin/echo "Additional component that shall only run on boot > success" > RemainAfterExit=yes > > [Install] > WantedBy=default.target > > # systemctl enable test.service systemd-boot-check-no-failures.service > Created symlink /etc/systemd/system/default.target.wants/test.service → > /etc/systemd/system/test.service. > Created symlink > /etc/systemd/system/boot-complete.target.requires/systemd-boot-check-no-failures.service > → /usr/lib/systemd/system/systemd-boot-check-no-failures.service. > > # systemctl reboot > > Unfortunately, the above results in: > > systemd[1]: multi-user.target: Found ordering cycle on test.service/start > systemd[1]: multi-user.target: Found dependency on > boot-complete.target/start > systemd[1]: multi-user.target: Found dependency on > systemd-boot-check-no-failures.service/start > systemd[1]: multi-user.target: Found dependency on multi-user.target/start > systemd[1]: multi-user.target: Job test.service/start deleted to break > ordering cycle starting with multi-user.target/start > > so what's the correct way to perform the mentioned "order [units] after > boot-complete.target", if they cannot be pulled in through the usual > default/multi-user targets? If I add DefaultDependencies=no to test.service > it now appears to work w/o the dependency cycle.
It should suffice adding After=multi-user.target to your service. The things is that systemd-boot-check-no-failures.service runs late, after the startup transaction is done to check if everything succeeded. But now you want to run something more, so by default s-b-c-n-f.s would also want to run after that, to know if it succeeded. But htat of course makes little sense: the output of your service cannot be part of the input of s-b-c-n-f.s if your service should run after s-b-c-n-f.s! So, my recommended fix: add After=multi-user.target to your service. Note that systemd handling of .wants/ works like this: 1. add Wants= type dep 2. if no After=/Before= dep is set, then also add Before= This means, that just adding an explicit After=multi-user.target to your service means rule #2 won't take effect anymore. With that in place things should just work (untested, but afaics), as it means s-b-c-n-f.s can run after multi-user.target, and then boot-complete.target after that, and then finally your service. Does that make sense? Lennart -- Lennart Poettering, Berlin