Greatings to you first
I am a student at the university, and my end of study project is to master an information security protocol for autonomous systems
I have a task in this project
when I type in the command line "kill [pid]", the process starts automatically after a delay of a few seconds
how I can achieve this task and thank you in advance
use systemd service
Create a file test.service under /etc/systemd/system, such as:
[Unit]
Description=test service
[Service]
User=root
Restart=always
# number of seconds to wait before restarting
RestartSec=5
# Change it to some meaningful processes
ExecStart=/bin/sleep 30000
[Install]
WantedBy=multi-user.target
To start the service: sudo systemctl start test.service
Then if you kill the process, it will automatically restart in 5 seconds
Note: if you modify the service file, you will have to run sudo systemctl daemon-reload and sudo systemctl restart test to reload the change
Related
I have made a daemon service in linux server. It is running well. The service file is
stargate.service (in /etc/systemd/system).
[Unit]
Description=stargate
[Service]
Type=simple
PIDFile=/app/stargate/stargate.pid
ExecStart=/app/stargate/stargate.sh start
ExecReload=/app/stargate/stargate.sh restart
ExecStop=/app/stargate/stargate.sh stop
[Install]
Alias=stargate
WantedBy=default.target
If by some reasons, the daemon service is die and stop. Do you know how to make the system automatically restart the daemon service ?
How to make the daemon service starts if server get rebooted?
To respawn your service when it fails, add the following to the [Service] block:
[Service]
Restart=on-failure
RestartSec=3
If you wish to always restart when your service is killed use Restart=always
The RestartSec value is the delay between restart attempts.
See more info here: https://www.freedesktop.org/software/systemd/man/systemd.service.html
I was trying to set up a Twonky Server on Ubuntu. The server works fine, but I could not get systemd to autostart the server (using a service file I created at /etc/systemd/system/twonkyserver.service). Sometimes I got the cryptic error message that some PID-file (/var/run/mediaserver.pid) is not accessible, the exit code of the service is 13, which apparently is a EACCES Permission denied error . The service runs as root.
I finally managed to fix the problem by setting PIDFile in the twonkyserver.service file to /var/run/mediaserver.pid. For reference, find the service file below:
[Unit]
Description=Twonky Server Service
After=network.target
[Service]
Type=simple
ExecStart=/usr/local/twonky/twonky.sh start
ExecStop=/usr/local/twonky/twonky.sh stop
ExecReload=/usr/local/twonky/twonky.sh reload
ExecRestart=/usr/local/twonky/twonky.sh restart
PIDFile=/var/run/mediaserver.pid
Restart=on-failure
[Install]
WantedBy=multi-user.target
As described above, the below service file auto-starts the Twonky Server on boot. Simply create it using vim /etc/systemd/system/twonkyserver.service. This assumses that you have installed the Twonky Server to usr/local/twonky. The shell-file twonky.sh already provides a nice interface to the service file (twonky.sh start|stop|reload|restart, also see twonky.sh -h).
[Unit]
Description=Twonky Server Service
After=network.target
[Service]
Type=simple
ExecStart=/usr/local/twonky/twonky.sh start
ExecStop=/usr/local/twonky/twonky.sh stop
ExecReload=/usr/local/twonky/twonky.sh reload
ExecRestart=/usr/local/twonky/twonky.sh restart
PIDFile=/var/run/mediaserver.pid
Restart=on-failure
[Install]
WantedBy=multi-user.target
I would slightly amend the start and stop commands from twonky.sh and put them directly into the twonky.service file for systemd:
[Unit]
Description=Twonky Server Service
After=network.target
[Service]
Type=simple
#Systemd will ensure RuntimeDirectory for the PID file is created under /var/run
RuntimeDirectory=twonky
PIDFile=/var/run/twonky/mediaserver.pid
# use the -mspid argument for twonkystarter to put the pid file in the right place
ExecStart=/usr/local/twonky/twonkystarter -mspid /var/run/twonky/mediaserver.pid -inifile /usr/local/twonky/twonkyserver.ini -logfile /usr/local/twonky/twonky.log -appdata /usr/local/twonky
ExecStop=kill -s TERM $MAINPID
ExecStopPost=-killall -s TERM twonkystarter
ExecStopPost=-killall -s TERM twonky
# Twonky 8.5.1 doesn't reload, it stops instead (on arm at least)
# ExecReload=kill -s HUP $MAINPID
Restart=on-failure
[Install]
WantedBy=multi-user.target
You need to be sure the paths in the ExecStart command match where you unpacked twonky, and also where you want the .pid file, configuration, logfile and runtime appdataunless you are happy with their default locations.
After putting that all into/etc/systemd/system/twonky.server, run
sudo systemctl daemon-reload
sudo systemctl start twonky
sudo systemctl enable twonky
I have managed to install daemon service in /etc/systemd/system, however I am not sure about 2 things:
Whether the daemon services should reside there
How can I elegantly check whether a daemon service is installed or not in systemd?
1.If the daemon services should reside there
yes, it is the .service location. The file that you should put here is:
mydeamon.service
[Unit]
Description=ROT13 demo service
After=network.target
StartLimitIntervalSec=0
[Service]
Type=simple
Restart=always
RestartSec=1
User=**YourUser**
ExecStart=**pathToYourScript**
[Install]
WantedBy=multi-user.target
You’ll need to:
set your actual username after User=
set the proper path to your script in ExecStart= (usually /usr/bin/ You can put your script here)
creating-a-linux-service-with-systemd
2.How can I elegantly check if a daemon service is installed or not in systemd?
systemctl has an is-active subcommand for this:
systemctl is-active --quiet service
will exit with status zero if service is active, non-zero otherwise, making it ideal for scripts:
systemctl is-active --quiet service && echo Service is running
test Service is running
I have a python app that I made it as a service on centos 7.
I created a file in /usr/lib/systemd/system with my project name. And wrote these on it:
[Unit]
Description=My Script Service
After=multi-user.target
[Service]
Type=idle
ExecStart=/usr/bin/python3.6 /usr/src/python-project/sampleService-services/serverprotocol.py
[Install]
WantedBy=multi-user.target
After that:
$ sudo systemctl daemon-reload
$ sudo systemctl enable sampleService.service
$ sudo reboot
I can start, restart and stop this service with commands:
$ systemctl start sampleService.service
$ systemctl restart sampleService
$ systemctl stop sampleService
But when i try to reload it with these commands:
$ systemctl reload sampleService
or
$ service sampleService reload
I get this error:
Failed to reload sampleService.service: Job type reload is not applicable for unit basiscore.service.
See system logs and 'systemctl status sampleService.service' for details.
Is there any command for reload this pythonic service ?!
how can I reload my service without restarting it ?!
Under the ExecStart= line, try to add
Restart=on-failure
RestartSec=10s
For systemctl reload ... to work, you need to provide an ExecReload= line in your unit (service) file. A common example is:
ExecReload=/bin/kill -HUP $MAINPID
That requires your program to catch and act on a SIGHUP signal. If your application has a different mechanism to trigger a reload of its configuration while running, then provide some other suitable command which generates that trigger.
I'm running a Debian web server with nginx and gunicorn running a django app. I've got everything up and running just fine but after rebooting the server I get a 502 bad gateway error. I've traced the issue back to gunicorn being inactive after the reboot. If I start the service the problem is fixed until I reboot the server again.
Starting the service:
systemctl start gunicorn.service
After the reboot here is my gunicorn service status:
{username}#instance-3:~$ sudo systemctl status gunicorn
● gunicorn.service - gunicorn daemon
Loaded: loaded (/etc/systemd/system/gunicorn.service; enabled)
Active: inactive (dead)
Contents of my /etc/systemd/system/gunicorn.service file:
[Unit]
Description=gunicorn daemon
After=network.target
[Service]
User={username}
Group={username}
WorkingDirectory=/home/{username}/web/{projname}
ExecStart=/usr/local/bin/gunicorn {projname}.wsgi:application
Restart=on-failure
[Install]
WantedBy=multi.user.target
Any ideas to figure out why the gunicorn service isn't starting after reboot?
Edit:
Could the issue be that the gunicorn.conf has a different dir in chdir and the exec than the working directory?
{username}#instance-3:~$ cat /etc/init/gunicorn.conf
cription "Gunicorn application server handling {projname}"
start on runlevel [2345]
stop on runlevel [!2345]
respawn
setuid {username}
setgid {username}
chdir /home/data-reporting/draco_reporting
exec {projname}/bin/gunicorn --workers 3 --bind unix:/home/{username}/data-reporting/{projname}/{projname}.sock {projname}.wsgi:application
You have a small typo in your gunicorn.service file. Change to:
WantedBy=multi-user.target
Also, you may want to change to:
Restart=always
I made old school crontab and the problem was solved.
crontab -e
and then
#reboot sudo systemctl restart nginx && sudo systemctl restart gunicorn.service
and just save crontab.