[systemd-devel] proper way for shutdown script

[Xen]

Lennart Poettering schreef op 05-10-2016 14:52:

>> nss_initgroups_ignoreusers
>> _apt,avahi,avahi-autoipd,backup,bin,colord,daemon,dnsmasq,games,gnats,hplip,irc,kernoops,list,lp,mail,man,messagebus,news,proxy,pulse,root,rtkit,saned,sddm,sshd,sync,sys,syslog,systemd-bus-proxy,systemd-network,systemd-resolve,systemd-timesync,unscd,usbmux,uucp,uuidd,whoopsie,www-data
> 
> Urgs, what an ugly approach...

:).

Still better than a non-booting system :p. So apparently this situation 
has already existed for quite some time.

Even worse is that by default the ldap configuration is set to 
bind-policy = hard, which can also create this issue (a failing LDAP 
query will then never return, or only return after a long timeout).

> It's the way to go on systemd. With current systemd you should be able
> to leave out the ExecStart=/bin/true bit, if you only care about
> shutdown?
> 
> But as I understood you actually wanted to run something both at boot
> and at shutdown, hence why would you not make use of ExecStart= as
> well here?

No that's not true.

I only wanted shutdown.

If the service never gets started how can it shut down?

ExecStop does weird things on services that are oneshot but not 
RemainAfterStart, at least.

> Note that the above unit file you posted is a bit contradictory: if
> you plug something into sysinit.target then your service should be an
> early-boot service, and those have to have the DefaultDependencies=no
> setting, as they need to configure their preicse ordering manually,
> instead of relying on the generic dependencies.

I realized that, but it works :p. The reason I picked it like this is 
because it *seems* that you might have rescue mode situations in which 
basic.target is never reached, neither is multi-user.target ever 
reached, but sysinit.target will be reached?

Since this is about the system remaining bootable I considered it reason 
enough to pick it like this :p.

> hence, either change the Wantedby= setting to
> WantedBy=multi-user.target and make the service a proper late-boot
> service, or also set DefaultDEpendencies=no and add the appropriate,
> manual early-boot dependencies.

Ya ya, it was documented also. I read it.