[systemd-devel] Problems trying to convert a System-V-Init script to systemd

[Holger Kiehl]

On Fri, 15 Jul 2016, Mantas Mikulėnas wrote:

> On Thu, Jul 14, 2016 at 3:34 PM, Holger Kiehl <Holger.Kiehl at dwd.de> wrote:
>       Hello,
> 
>       I am new to systemd and the maintainer of the file distribution
>       software
>       AFD (http://www.dwd.de/AFD) and I am trying to adapt this
>       application
>       to systemd. The problem I am unable to solve is that doing a
>       reboot,
>       poweroff or halt, all process get a SIGTERM before systemd calls
>       the
>       command supplied by ExecStop. If I do a 'systemctl stop
>       afd.service'
>       everything works as expected. I have searched the web for a
>       solution
>       and have tried all the different service Type=, unit
>       After=/Before=
>       combination, but failed so far. I must be doing something
>       obviously
>       wrong, but unable to see what and need help please.
> 
>       The service/unit file looks as follows:
> 
>          [Unit]
>          Description=Automatic File Distributor
>          After=basic.target
> 
>          [Service]
>          RemainAfterExit=yes
>          Type=oneshot
>          ExecStart=-/etc/init.d/afd start
>          ExecStop=-/etc/init.d/afd stop
>          KillMode=none
>          StandardOutput=syslog+console
>          StandardError=syslog+console
> 
>          [Install]
>          WantedBy=multi-user.target
> 
>       /etc/init.d/afd is a shell script that starts one or more
>       instances of
>       the AFD under different users. The users are configured in
>       /etc/sysconfig/afd
>       and are started via the following command: su - $afduser -c
>       "<cmd start/sop AFD>"
>       To speed things up a bit the script forks for each user to
>       start/stop the
>       AFD instances. The script /etc/init.d/afd is just initiating
>       thinks, but
>       always waits for the command to complete. AFD itself has an init
>       process
>       (init_afd) that then starts several other process and monitors
>       them.
> 
> 
> It's possible that `su` moves its children to a different cgroup, making
> them no longer technically part of the service, but rather part of a user
> session.
> 
> Check whether `systemctl status afd` actually shows your sub-daemons while
> they're running... (Other useful tools are `systemd-cgls` or `ps axfo
> pid,user,unit,cmd`.) If that's the problem, try using `runuser -u $afduser
> …` instead.
> 
You are right. See my other mail I just send. systemd-cgls shows that it
is part of the user session. I did try running it with runuser, but that
does not work because AFD needs the user environment, that whats in
~/.profile (or .bash_profile, .cshrc, .login, etc).

> Better yet, forget init.d and create a native afd at .service, with one
> instance per user (afd at user1, afd at user2, etc.), each instance running
> *exactly one* daemon.
> 
But I have users that run multiple AFD's under one user, each in their on
working directory. Can this be done, without having to manually write a
unit file for each AFD instance?

Regards,
Holger