On Wed, Dec 06, 2017 at 05:35:46PM +0100, DGSJ wrote:
> Hallo.
> In order to migrate my SistemV to Runit, I'm writing the service scripts,
> but I'm having a problem I can't solve.
All right, lets take a look!
> 
> First, lest see an example that works well. The run file for the 
> touchpad mouse:
> 
> #!/bin/bash
> [ -f /etc/sysconfig/mouse ] && . /etc/sysconfig/mouse
> echo -e "Mouse working (ratonpad)..."
> exec /usr/sbin/gpm -D -m "${MDEVICE}" -t "${PROTOCOL}" ${GPMOPTS} > /dev/null 
> 2>&1
> 
> An this is how the processes and PID's look like.
> # ps -fx 
>   1 ?        Ss     0:00 runit
> 192 ?        Ss     0:00 runsvdir -P /service log: ..................
> .....................................................................
> 194 ?        Ss     0:00  \_ runsv ratonpad
> 198 ?        S      0:00  |   \_ /usr/sbin/gpm -D -m /dev/input/mice -t imps2
> 
> This kind of run file seems to work fine with daemons like gpm, sysklogd
> syslogd...
> 
> But when I try to make the same with other services like udev, something 
> goes wrong.
> 
> This is the run file:
> #!/bin/bash -e
> echo "daemon udevd"
> exec 2>&1
> exec /sbin/udevd --daemon
> 
> And this is what happens:
> 466 ?        Ss     0:00 /sbin/udevd --daemon
> 470 ?        Ss     0:00 /sbin/udevd --daemon
> 474 ?        Ss     0:00 /sbin/udevd --daemon
> 478 ?        Ss     0:00 /sbin/udevd --daemon
> 484 ?        Ss     0:00 /sbin/udevd --daemon
> 488 ?        Ss     0:00 /sbin/udevd --daemon
> 492 ?        Ss     0:00 /sbin/udevd --daemon
> 496 ?        Ss     0:00 /sbin/udevd --daemon
> 
> The processes doesn't fit into the typical runsv tree, and every one second
> a new PID is created on and on.
> 
> What can be wrong?
systemd-udevd(8) says: --daemon Detach and run in the background.

The main thing about supervision is that things shouldn't background
themselves, otherwise the supervisor loses track of it and spawns a new
copy. Dropping the `--daemon' should fix it.
> 
> With other more elaborated run files, for services different than daemons, 
> it happens more or less the same. Let see the behaviour of this 
> interesting template I have found.
> 
> This is the run file.
> #!/bin/bash -e
> echo -e "-------------"
> exec 2>&1
> exec /opt/example2/foo-service.sh 
> 
> This is the script for the foo-service.sh
> #!/bin/bash -e
> echo "Empieza el servicio...root (service begins)"
> for i in {1..2}
> do
>     echo "haciendo cosas...root (making things...)"
>     sleep 1
> done
> 
> It doesn't matter if you end the script with exit 1 o 0, the result,
> regarding the uncontrolled creation of PID's is the same.
> 
> This is the output of ps -fx
> 
> 197 ?        Ss     0:00  \_ runsv example2
> 820 ?        S      0:00      \_ /bin/bash -e /opt/example2/foo-service.sh
> 821 ?        S      0:00          \_ sleep 1
> 
> It looks nice, but after a while:
> 197 ?        Ss     0:00  \_ runsv example2
> 989 ?        S      0:00      \_ /bin/bash -e /opt/example2/foo-service.sh
> 991 ?        S      0:00          \_ sleep 1
This is a matter of confusion on the part of the user. ./run is being
replaced via exec with foo-service.sh, a program that does three things:
echoes some stuff, forks a one-second sleep, and then exits. Once it
exits, the supervisor (runsv) will re-launch it.
> 
> Old processes are killed, and new ones created every second
> 820 - 821 --> 989 - 991.
> 
> Another view with pstree.
>       |-runsvdir-+-runsv---login---bash---
>       |          |                        
>       |          |-runsv---gpm
>       |          |-runsv---syslogd
>       |          |-runsv-+-klogd
>       |          |       `-run---svlogd
>       |          `-runsv---foo-service.sh---sleep
> 
> 
> Well, I think I've missed something... 
> 
> It seems that every time the service is controlled, at the same time the
> process is recreated again and again with increasing PIDs. 
> What am I doing wrong?
In your test case, the design of foo-service.sh is the problem. If you
replaced `for i in {1..2} ; do' with `while : ; do' the script will
never actually terminate and foo-service.sh will be properly supervised. 
> 
> I'm very interested in using runit for controlling other services different
> than daemons, so any help will be welcomed.
The only rules are: it has to not background/detatch/whatever, and when
it terminates it'll get re-launched.
> 
> Thank you in advance for your help.
Cheers!
> -- 
> -------------------------
> Daniel Gutiérrez San José

-- 
Colin Booth

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