srp_daemon: Detect proper path to systemctl

[nmorey]

While debian uses /bin/systemctl, SUSE only supports /usr/bin/systemctl,
causing srp_daemon to fail silently starting on all ports.
Detect at built which path is the right one and use it.

Fixes: b03beb1 ("srp_daemon: Call systemctl properly from udev")
Signed-off-by: Nicolas Morey-Chaisemartin nmoreychaisemartin@suse.com

[nmorey]

@Honggang-LI @bdrung
Hopefully this patch should get the proper path for all distros. Could you check it does work well on yours ?

[Honggang-LI]

@Honggang-LI @bdrung Hopefully this patch should get the proper path for all distros. Could you check it does work well on yours ?

Tested it with fedora-35. It works for me.

Thanks

[bdrung]

I tested building the master branch on Debian unstable, and 60-srp_daemon.rules got evaluated to:

SUBSYSTEM=="infiniband_mad", KERNEL=="*umad*", PROGRAM=="SYSTEMCTL_BIN-NOTFOUND show srp_daemon -p ActiveState", RESULT=="ActiveState=active", ENV{SYSTEMD_WANTS}+="srp_daemon_port@$attr{ibdev}:$attr{port}.service"

This is caused by not having systemd installed in the minimal chroot environment. Please fall back to use /bin/systemctl if the binary is not found or provide a way to configure it during build.

[rleon]

@nmorey, are you fixing it?