[ClusterLabs] pacemaker systemd resource

[Ken Gaillot]

On Wed, 2020-07-22 at 17:04 +0300, Andrei Borzenkov wrote:
> 
> 
> On Wed, Jul 22, 2020 at 4:58 PM Ken Gaillot <kgaillot at redhat.com>
> wrote:
> > On Wed, 2020-07-22 at 10:59 +0300, Хиль  Эдуард wrote:
> > > Hi there! I have 2 nodes with Pacemaker 2.0.3, corosync 3.0.3 on
> > > ubuntu 20 + 1 qdevice. I want to define new resource as systemd
> > > unit dummy.service :
> > >  
> > > [Unit]
> > > Description=Dummy
> > > [Service]
> > > Restart=on-failure
> > > StartLimitInterval=20
> > > StartLimitBurst=5
> > > TimeoutStartSec=0
> > > RestartSec=5
> > > Environment="HOME=/root"
> > > SyslogIdentifier=dummy
> > > ExecStart=/usr/local/sbin/dummy.sh
> > > [Install]
> > > WantedBy=multi-user.target
> > >  
> > > and /usr/local/sbin/dummy.sh :
> > >  
> > > #!/bin/bash
> > > CNT=0
> > > while true; do
> > >   let CNT++
> > >   echo "hello world $CNT"
> > >   sleep 5
> > > done
> > >  
> > > and then i try to define it with: pcs resource create
> > dummy.service
> > > systemd:dummy op monitor interval="10s" timeout="15s"
> > > after 2 seconds node2 reboot. In logs i see pacemaker in 2
> > seconds
> > > tried to start this unit, and it started, but pacemaker somehow
> > think
> > > he is «Timed Out» . What i am doing wrong? Logs below.
> > 
> > The start is timing out because the ExecStart script never returns.
> > 
> 
> Type=simple does not expect script to go into background. Quite the
> contrary - systemd expects ExecStart command to remain, going into
> background would be interpreted as "service terminated".
> 
> To quote systemd: "the service manager will consider the unit started
> immediately after the main service process has been forked off. It is
> expected that the process configured with ExecStart= is the main
> process of the service".
> 
>  
> > systemd starts processes but it doesn't daemonize them -- the
> > script is
> > responsible for doing that itself. 
> 
> Only for Type=forking

Ah, my bad, sorry for the noise :)
 
> > You can search online for more
> > details about daemonization, but most importantly you want to run
> > your
> > daemon as a subprocess in the background and have your main process
> > return as soon as the daemon is ready for service.
> > 
> > 
> > > Jul 21 15:53:41 node2.local pacemaker-controld[1813]:  notice:
> > Result
> > > of probe operation for dummy.service on node2.local: 7 (not
> > running) 
> > > Jul 21 15:53:41 node2.local systemd[1]: Reloading.
> > > Jul 21 15:53:42 node2.local systemd[1]:
> > > /lib/systemd/system/dbus.socket:5: ListenStream= references a
> > path
> > > below legacy directory /var/run/, updating
> > > /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket;
> > please
> > > update the unit file accordingly.
> > > Jul 21 15:53:42 node2.local systemd[1]:
> > > /lib/systemd/system/docker.socket:6: ListenStream= references a
> > path
> > > below legacy directory /var/run/, updating /var/run/docker.sock →
> > > /run/docker.sock; please update the unit file accordingly.
> > > Jul 21 15:53:42 node2.local pacemaker-execd[1808]:  notice:
> > Giving up
> > > on dummy.service start (rc=0): timeout (elapsed=259719ms,
> > remaining=-
> > > 159719ms)
> > > Jul 21 15:53:42 node2.local pacemaker-controld[1813]:  error:
> > Result
> > > of start operation for dummy.service on node2.local: Timed Out 
> > > Jul 21 15:53:42 node2.local systemd[1]: Started Cluster
> > Controlled
> > > dummy.
> > > Jul 21 15:53:42 node2.local dummy[9330]: hello world 1
> > > Jul 21 15:53:42 node2.local systemd-udevd[922]: Network interface
> > > NamePolicy= disabled on kernel command line, ignoring.
> > > Jul 21 15:53:42 node2.local pacemaker-attrd[1809]:  notice:
> > Setting
> > > fail-count-dummy.service#start_0[node2.local]: (unset) ->
> > INFINITY 
> > > Jul 21 15:53:42 node2.local pacemaker-attrd[1809]:  notice:
> > Setting
> > > last-failure-dummy.service#start_0[node2.local]: (unset) ->
> > > 1595336022 
> > > Jul 21 15:53:42 node2.local systemd[1]: Reloading.
> > > Jul 21 15:53:42 node2.local systemd[1]:
> > > /lib/systemd/system/dbus.socket:5: ListenStream= references a
> > path
> > > below legacy directory /var/run/, updating
> > > /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket;
> > please
> > > update the unit file accordingly.
> > > Jul 21 15:53:42 node2.local systemd[1]:
> > > /lib/systemd/system/docker.socket:6: ListenStream= references a
> > path
> > > below legacy directory /var/run/, updating /var/run/docker.sock →
> > > /run/docker.sock; please update the unit file accordingly.
> > > Jul 21 15:53:42 node2.local pacemaker-execd[1808]:  notice:
> > Giving up
> > > on dummy.service stop (rc=0): timeout (elapsed=317181ms,
> > remaining=-
> > > 217181ms)
> > > Jul 21 15:53:42 node2.local pacemaker-controld[1813]:  error:
> > Result
> > > of stop operation for dummy.service on node2.local: Timed Out 
> > > Jul 21 15:53:42 node2.local systemd[1]: Stopping Daemon for
> > dummy...
> > > Jul 21 15:53:42 node2.local pacemaker-attrd[1809]:  notice:
> > Setting
> > > fail-count-dummy.service#stop_0[node2.local]: (unset) ->
> > INFINITY 
> > > Jul 21 15:53:42 node2.local pacemaker-attrd[1809]:  notice:
> > Setting
> > > last-failure-dummy.service#stop_0[node2.local]: (unset) ->
> > > 1595336022 
> > > Jul 21 15:53:42 node2.local systemd[1]: dummy.service: Succeeded.
> > > Jul 21 15:53:42 node2.local systemd[1]: Stopped Daemon for dummy.
> > > ... lost connection (node rebooting)
> > >  
> > >  
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-- 
Ken Gaillot <kgaillot at redhat.com>