systemd problem

[Seraangel]

Hi I have written a systemd service for imapfilter. When I start this imapfilter also runs once. However, the process does not stay active and continues to check the emails at the specified interval. Status of the service dead. However, when I call imapfilter in the shell, the constant check in the interval works and the process remains.

Can anyone give me a hint what I am doing wrong?

I am using imapfilter version 2.6.12.

[lefcha]

Do you mean that when running inside systemd, the interval for sleeping is not respected, and instead it does a continuous loop?

And are the 2 configs (when run inside systemd and from the shell) exactly the same?

Or that it dies when running inside systemd, and thus continuously restarted by systemd?

[Seraangel]

Hi a little more details:

at the end of my config.lua: become_daemon(600, <function>)

my systemd.service:

[Unit]
Description=ImapFilter Client Daemon
Documentation=man:imapfilter
# Start after network and specified mounts are available.
After=network-online.target

[Service]
Type=simple
User=<user>
Group=<user>
ExecStart=/usr/bin/imapfilter -c ./.imapfilter/config.lua -l /var/log/imapfilter/imapfilter.log
WorkingDirectory=/home/<user>/
Restart=on-failure
StartLimitIntervalSec=3

# Time to wait before forcefully stopped.
TimeoutStopSec=30

[Install]
WantedBy=multi-user.target

when I start the service:

● imapfilter.service - ImapFilter Client Daemon
   Loaded: loaded (/etc/systemd/system/imapfilter.service; enabled; vendor preset: enabled)
   Active: inactive (dead) since Sun 2021-12-12 16:59:28 CET; 1s ago
     Docs: man:imapfilter
  Process: 6181 ExecStart=/usr/bin/imapfilter -c ./.imapfilter/config.lua -l /var/log/imapfilter/imapfilter.log (code=exited, status=0/SUCCESS)
 Main PID: 6181 (code=exited, status=0/SUCCESS)

Dez 12 16:59:26 device systemd[1]: Started ImapFilter Client Daemon.
Dez 12 16:59:27 device imapfilter[6181]: <output>
Dez 12 16:59:28 device systemd[1]: imapfilter.service: Succeeded.

So it run once successfully but seems to ignore the become_daemon functionality. When I ssh to the shell and use imapfilter on user, the process keeps running and the demon works every 10 minutes.

What am I doing wrong?

[lefcha]

I tried this, and indeed it seems that imapfilter doesn't run correctly as a systemd service using become_daemon(). I suspect that it might be because imapfilter becomes daemon by use of the fork() function.

Since systemd handles running services as daemons itself, you can structure your config like this:

function loop()
    -- your commands
end

-- become_daemon(600, loop)
while true
    loop()
    sleep(600)
end

So the loop function is repeated with the same interval, but imapfilter runs as a normal process, and not as a daemon.

I have tried this systemd, and it seems to work as expected.