Arch Linux

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 768

[Solved] systemctl seems to start and stop my service when I run start

I've written a simple .service to enable a script I wrote as a service:

[Unit]
Description=run through a list of netcfg profiles starting them in order and stopping when one connects succesfully.
Before=network.target
Wants=network.target
Conflicts=netcfg.service

[Service]
Type=oneshot
ExecStart=/usr/bin/netcfg-manager
ExecStop=/usr/bin/netcfg -a

[Install]
WantedBy=multi-user.target

when I run

systemctl start netcfg-manager.service

and the request the status I get the following output from the status request:

netcfg-manager.service - run through a list of netcfg profiles starting them in order and stopping when one connects succesfully.
	  Loaded: loaded (/usr/lib/systemd/system/netcfg-manager.service; disabled)
	  Active: inactive (dead) since Sun 2013-01-27 20:12:28 UTC; 3s ago
	 Process: 1834 ExecStop=/usr/bin/netcfg -a (code=exited, status=0/SUCCESS)
	 Process: 1821 ExecStart=/usr/bin/netcfg-manager (code=exited, status=0/SUCCESS)

Jan 27 20:12:28 kirstine netcfg-manager[1821]: ethernet-static already connected
Jan 27 20:12:28 kirstine netcfg[1834]: :: ethernet-static down [done]

Which suggests to me that it is running both ExecStart and ExecStop when I simply ask it to start.

Obviously this is a problem.

Can anyone shed any light on what it going on here?

I don't think it's a factor, but, just in case, here is the script that gets called:

#!/bin/bash
i=0
while read line; do
        # ignore comment lines
        echo "$line" | grep "^#" >/dev/null 2>&1 && continue
        profiles[i]=$line
        ((i++))
done < /etc/netcfg-manager.conf
for p in ${profiles[@]}
do
        netcfg -u $p
        if [ $? -eq 0 ]
        then
                echo "Started profile $p succesfully";
                break;
        fi
done

Last edited by phunni (2013-01-28 10:56:14)

chris_l

Member

Registered: 2010-12-01

Posts: 390

Re: [Solved] systemctl seems to start and stop my service when I run start

well, from man systemd.service

Type=
           Behavior of oneshot is similar to simple, however it is expected that the process has to exit before systemd starts follow-up units. RemainAfterExit= is particularly useful for this type of service.
RemainAfterExit=
           Takes a boolean value that specifies whether the service shall be considered active even when all its processes exited. Defaults to no.

Not sure 100%, but probably if you set RemainAfterExit to yes

...and why you are doing this instead of systemctl enable netcfg@<profile> ?

---

"open source is about choice"
No.
Open source is about opening the source code complying with this conditions, period. The ability to choose among several packages is just a nice side effect.

Trilby

Inspector Parrot

Registered: 2011-11-29

Posts: 29,523

Website

Re: [Solved] systemctl seems to start and stop my service when I run start

Or set type to forking.

---

"UNIX is simple and coherent..." - Dennis Ritchie, "GNU's Not UNIX" -  Richard Stallman

chris_l

Member

Registered: 2010-12-01

Posts: 390

Re: [Solved] systemctl seems to start and stop my service when I run start

Or set type to forking.

hmm.
As a forking service, the parent is expected to end, and the cgroup will contain the children (not sure about what would happen with the children using oneshot+RemainAfterExit )

However, the official netcfg.service and netcfg@.service files are set as oneshot+RemainAfterExit instead of forking.
Since there are not children process from netcfg (none that I have seen, maybe Im wrong), I think that maybe, the right thing™™ is oneshot+RemainAfterExit instead of forking.

---

"open source is about choice"
No.
Open source is about opening the source code complying with this conditions, period. The ability to choose among several packages is just a nice side effect.

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 768

Re: [Solved] systemctl seems to start and stop my service when I run start

...and why you are doing this instead of systemctl enable netcfg@<profile> ?

Because this is different

I want netcfg to try profiles in a given order and then stop when one succeeds.  As far as I can tell (and from conversations about it on this very board) netcfg doesn't have this functionality.  So, I've written a script to extend it.

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 768

Re: [Solved] systemctl seems to start and stop my service when I run start

BTW using RemainAfterExit=yes appears to have worked.  Thanks.