blog.nek0.eu/site/posts/2014-10-23-Daemonize-a-yesod-app.md

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2016-03-01 07:03:27 +00:00
---
title: Daemonize a Yesod application
author: nek0
tags: english, meta, programming
description: Found a way to daemonize my commenting service
---
**If you want to create a systemd service file, look [here][systemd]**
As you might know I have written my own commenting service, which up until recently I had to start manually in a [screen](https://www.gnu.org/software/screen/) session. Then I decided to write my own init-script.
I have to admit, that I am no experienced sysadmin or something like that, but just a random guy with a strange love (or addiction) to computers. So this is my first time doing this.
For managing the starting and stopping of the service I chose to use the start-stop-daemon shipped with the system on my server. Additionally I used the skeleton file for init-scripts, which you can find in `/etc/init.d/skeleton`.
After consulting the manpage of start-stop-daemon I came up with the following command for starting the commenting service:
```bash
start-stop-daemon --start -b -u nek0 --chuid nek0 --name yacs --exec ./yacs -d /home/nek0/www/yacs-run/ \
-- config/settings.yml > /var/log/yacs.log
```
What this actually means: The first option ist pretty self explanatory. `-b` starts the service in the background. `-u` and `--chuid` ensure, that the service runs as a user, not as root. I chose my own user here, but you can also use `nobody` if you like. The name of the service is specified by `--name`. `-d` specifies the working directory of the service you want to start and finally `--exec` is the path to the executable, in this case relative to the working directory. Everything after the final double-dashes are arguments passed to the executable itself.
for stopping the whole thing I use the following command:
```bash
start-stop-daemon --stop -u nek0 --name yacs
```
This is even simpler than the above and is really self explanatory after all the information you got above.
the whole init-script looks like this:
```bash
#! /bin/sh
### BEGIN INIT INFO
# Provides: yacs
# Required-Start: $nginx
# Required-Stop:
# Default-Start: 2 3 4 5
# Default-Stop:
# Short-Description: Start YACS commenting service
# Description: start YACS commenting service
### END INIT INFO
case "$1" in
start)
logger starting YACS
start-stop-daemon --start -b -u nek0 --chuid nek0 --name yacs --exec ./yacs -d /home/nek0/www/yacs-run/ \
-- config/settings.yml > /var/log/yacs.log
;;
stop)
logger stopping YACS
start-stop-daemon --stop -u nek0 --name yacs
;;
restart)
logger restarting YACS
start-stop-daemon --stop -u nek0 --name yacs
start-stop-daemon --start -b -u nek0 --chuid nek0 --name yacs --exec ./yacs -d /home/nek0/www/yacs-run/ \
-- conifg/settings.yml > /var/log/yacs.log
;;
status)
# No-op
;;
*)
echo "Usage: yacs {start|stop|restart}" >&2
exit 3
;;
esac
```
I hope this is helpful for others. If something is unclear, you can always leave a comment now ^^
2016-07-05 13:56:17 +00:00
[systemd]:https://nek0.eu/posts/2015-08-28-Daemonize-a-Yesod-application-systemd-style.html