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How to run a shell script at startup


Question

On an Amazon S3 Linux instance, I have two scripts called start_my_app and stop_my_app which start and stop forever (which in turn runs my Node.js application). I use these scripts to manually start and stop my Node.js application. So far so good.

My problem: I also want to set it up such that start_my_app is run whenever the system boots up. I know that I need to add a file inside init.d and I know how to symlink it to the proper directory within rc.d, but I can't figure out what actually needs to go inside the file that I place in init.d. I'm thinking it should be just one line, like, start_my_app, but that hasn't been working for me.

2019/12/30
1
378
12/30/2019 11:46:08 PM

Accepted Answer

In the file you put in /etc/init.d/ you have to set it executable with:

chmod +x /etc/init.d/start_my_app

Thanks to @meetamit, if this does not run you have to create a symlink to /etc/rc.d/

ln -s /etc/init.d/start_my_app /etc/rc.d/

Please note that on latest Debian, this will not work as your script have to be LSB compliant (provide, at least, the following actions: start, stop, restart, force-reload, and status): https://wiki.debian.org/LSBInitScripts

As a note, you should put the absolute path of your script instead of a relative one, it may solves unexpected issues:

/var/myscripts/start_my_app

And don't forget to add on top of that file:

#!/bin/sh
2015/03/19
298
3/19/2015 8:49:47 AM


A simple approach is to add a line in /etc/rc.local :

/PATH/TO/MY_APP &

or if you want to run the command as a special user :

su - USER_FOOBAR -c /PATH/TO/MY_APP &

(the trailing ampersand backgrounds the process and allows the rc.local to continue executing)

If you want a full init script, debian distro have a template file, so :

cp /etc/init.d/skeleton /etc/init.d/your_app

and adapt it a bit.

2019/09/06

This is the way I do it on Red Hat Linux systems.

Put your script in /etc/init.d, owned by root and executable. At the top of the script, you can give a directive for chkconfig. Example, the following script is used to start a Java application as user oracle.

The name of the script is /etc/init.d/apex

#!/bin/bash
# chkconfig: 345 99 10
# Description: auto start apex listener
#
case "$1" in
 'start')
   su - oracle -c "cd /opt/apex ; java -jar apex.war > logs/apex.log 2>logs/apex_error.log &";;
 'stop')
   echo "put something to shutdown or kill the process here";;
esac

This says that the script must run at levels 3, 4, and 5, and the priority for start/stop is 99 and 10.

Then, as user root you can use chkconfig to enable or disable the script at startup:

chkconfig --list apex
chkconfig --add apex

And you can use service start/stop apex.

2019/12/30

Enter cron using sudo:

sudo crontab -e

Add a command to run upon start up, in this case a script:

@reboot sh /home/user/test.sh

Save:

Press ESC then :x to save and exit, or hit ESC then ZZ (that's shift+zz)

Test Test Test:

  1. Run your test script without cron to make sure it actually works.

  2. Make sure you saved your command in cron, use sudo crontab -e

  3. Reboot the server to confirm it all works sudo @reboot

2018/03/06

Just have a line added to your crontab..

Make sure the file is executable:

chmod +x /path_to_you_file/your_file

To edit crontab file:

crontab -e

Line you have to add:

@reboot  /path_to_you_file/your_file

That simple!

2016/11/10

Another option is to have an @reboot command in your crontab.

Not every version of cron supports this, but if your instance is based on the Amazon Linux AMI then it will work.

2013/11/10