<div dir="ltr"> <div class="gmail_extra"> <div class="gmail_quote">On Mon, Mar 19, 2018 at 5:52 PM, John Ioannidis <<a href="mailto:systemd-devel@tla.org" target="_blank">systemd-devel@tla.org</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>I want to have a service with several instances, each of which has a configuration file; when configuration files appear and disappear, I want the corresponding instances to be created and started, and die, respectively, and in particular have the running processes corresponding to the removed units be killed. </div> I can get them to start the first time, but they do not stop when configuration files change. If I systemctl daemon-reload, the links in /run/systemd/system-generators get properly adjusted, but I cannot figure out how to tell my service to kill the no-longer-needed processes. If I also systemctl reload the service, all existing processes are killed, which is absolutely not what I want.<div> </div><div><span style="color:rgb(34,34,34);font-family:"times new roman",serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">Here is what I've done: what am I doing wrong? I tried modelling this after what OpenVPN does: # cat /etc/systemd/system/letters.service [Unit] Description=Letters service After=network.target [Service] Type=oneshot RemainAfterExit=yes ExecStart=/bin/true ExecReload=/bin/true WorkingDirectory=/var/tmp/letters [Install] WantedBy=multi-user.target # cat /etc/systemd/system/letters@.service [Unit] Description=Letters for %i PartOf=letters.service ReloadPropagatedFrom=letters.service Before=systemd-user-sessions.service After=syslog.target network-online.target Wants=network-online.target [Service] Type=simple PrivateTmp=false WorkingDirectory=/var/tmp/letters ExecStart=/usr/local/bin/letter --daemon --pidfile /run/letters/%i.pid PIDFile=/run/letters/%i.pid ExecReload=/bin/kill -HUP $MAINPID DeviceAllow=/dev/null rw ProtectSystem=true ProtectHome=true [Install] WantedBy=multi-user.target # cat /etc/systemd/system-generators/letters #!/bin/sh exec 2>> /tmp/opg2 set -eux GENDIR="$1" WANTDIR="$1/letters.service.wants" SERVICEFILE="/lib/systemd/system/letters@.service" CONFIG_DIR=/var/letters/ mkdir -p "$WANTDIR" for CONFIG in `cd $CONFIG_DIR; ls *.conf 2> /dev/null`; do NAME=${CONFIG%%.conf} ln -s "$SERVICEFILE" "$WANTDIR/letters@$NAME.service" done exit 0 Now for the fun:<div> </div><div># touch /var/letters/aleph.conf /var/letters/e.conf /var/letters/zeta.conf</div><div># systemctl daemon-reload # ls -l /run/systemd/generator/letters.service.wants total 0 lrwxrwxrwx 1 root root 36 Mar 19 17:37 letters@aleph.service -> /lib/systemd/system/letters@.service lrwxrwxrwx 1 root root 36 Mar 19 17:37 letters@e.service -> /lib/systemd/system/letters@.service lrwxrwxrwx 1 root root 36 Mar 19 17:37 letters@zeta.service -> /lib/systemd/system/letters@.service # systemctl enable letters.service Created symlink /etc/systemd/system/multi-user.target.wants/letters.service → /etc/systemd/system/letters.service. # systemctl start letters.service # ps ax | grep lett 22853 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/e.pid 22927 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/aleph.pid 22928 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/zeta.pid </div><div>So far so good. This is working as expected. Even better:</div><div> </div><div># touch /var/letters/tcha.conf # systemctl daemon-reload # systemctl start letters.service # ps ax | grep lett 22853 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/e.pid 22927 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/aleph.pid 22928 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/zeta.pid 23083 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/tcha.pid </div><div>But now the trouble begins:</div><div> </div><div># rm /var/letters/e.conf # systemctl daemon-reload # ls -l /run/systemd/generator/letters.service.wants total 0 lrwxrwxrwx 1 root root 36 Mar 19 17:44 letters@aleph.service -> /lib/systemd/system/letters@.service lrwxrwxrwx 1 root root 36 Mar 19 17:44 letters@tcha.service -> /lib/systemd/system/letters@.service lrwxrwxrwx 1 root root 36 Mar 19 17:44 letters@zeta.service -> /lib/systemd/system/letters@.service </div><div><span style="color:rgb(34,34,34);font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><span style="color:rgb(34,34,34);font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">The link letters@e.service has been correctly removed, but the corresponding process still exists:</div><div># ps ax | grep e.pid 22853 ? S 0:00 /usr/local/bin/letter --daemon --pidfile /run/letters/e.pid </div><div> </div> <div> </div></div></div> </blockquote></div> </div><div class="gmail_extra">I also tried this with requires instead of wants, but the behavior is the same.</div><div class="gmail_extra"> </div></div>