How can I trigger a script say A (in python) using Jenkins such that a shell script triggered internally from script A keeps running in background even after Jenkins build is done.
Right now, what I observe is that as soon as Jenkins job ends, it kills the background shell script too.
However, running the python script manually on the terminal is fine.
Is there a way that I can skip killing that background shell script from Jenkins?
After searching for the solution, I came across this link "Spawning process from build"
https://wiki.jenkins.io/display/JENKINS/Spawning+processes+from+build
Adding below command to build step helped:
BUILD_ID=dontKillMe nohup shell_script_to_run.sh &
Related
I have a complex python 2.7 script that is launched by a node.js app using spawn. This script runs fine most of the time, but occasionally, it crashes and I don't know why. I did not have this problem when launching the script from the command line or as a service.
To simulate this, I start the script via node.js, get the process id using the ps or pgrep command, then kill it using kill -9 on the process id. My question is how do my script to generate an error code or debug output when it crashes unexpectedly?
I've coded a stock trading bot in Python3. I have it hosted on a server (Ubuntu 18.10) that I use iTerm to SSH into. Wondering how to keep the script actively running so that when I exit out of my session it won't kill the active process.
Basically, I want to SSH into my server, start the script then close out and come back into it when the days over to stop the process.
You could use nohup and add & at the end of your command to safely exit you session without killing original process. For example if your script name is script.py:
nohup python3 script.py &
Normally, when running a command using & and exiting the shell afterwards, the shell will terminate the sub-command with the hangup signal (kill -SIGHUP <pid>). This can be prevented using nohup, as it catches the signal and ignores it so that it never reaches the actual application.
You can use screen
sudo apt-get install screen
screen
./run-my-script
Ctrl-A then D to get out of your screen
From there you will be able to close out your ssh terminal. Come back later and run
screen -ls
screen -r $screen_running
The screen running is usually the first 5 digits you see after you've listed all the screens. You can see if you're script is still running or if you've added logging you can see where in the process you are.
Using tmux is a good option. Alternatively you could run the command with an & at the end which lets it run in the background.
https://tmuxcheatsheet.com/
I came here for finding nohup python3 script.py &
Right solution for this thread is screen OR tmux. :)
I know this is an exact copy of this question, but I've been trying different solutions for a while and didn't come up with anything.
I have this simple script that uses PRAW to find posts on Reddit. It takes a while, so I need it to stay alive when I log out of the shell as well.
I tried to set it up as a start-up script, to use nohup in order to run it in the background, but none of this worked. I followed the quickstart and I can get the hello word app to run, but all these examples are for web applications and all I want is start a process on my VM and keep it running when I'm not connected, without using .yaml configuration files and such. Can somebody please point me in the right direction?
Well, at the end using nohup was the answer. I'm new to the GNU environment and I just assumed it didn't work when I first tried. My program was exiting with an error, but I didn't check the nohup.out file so I was unaware of it..
Anyway here is a detailed guide for future reference (Using Debian Stretch):
Make your script an executable
chmod +x myscript.py
Run the nohup command to execute the script in the background. The & option ensures that the process stays alive after exiting. I've added the shebang line to my python script so there's no need to call python here
nohup /path/to/script/myscript.py &
Logout from the shell if you want
logout
Done! Now your script is up and running. You can login back and make sure that your process is still alive by checking the output of this command:
ps -e | grep myscript.py
I have 3-4 python scripts which I want to run continuously on a remote server(which i am accessing through ssh login).The script might crash due to exceptions(handling all the exceptions is not practical now), and in such cases i want to immediately restart the script.
What i have done till now.
I have written a .conf file in /etc/init
chdir /home/user/Desktop/myFolder
exec python myFile.py
respawn
This seemed to work fine for about 4 hours and then it stopped working and i could not start the .conf file.
Suggest changes to this or i am also open to a new approach
Easiest way to do it - run in infinite bash loop in screen. Also it's the worst way to do it:
screen -S sessionName bash -c 'while true; python myFile.py ; done'
You can also use http://supervisord.org/ or daemon by writing init.d script for it http://www.linux.com/learn/tutorials/442412-managing-linux-daemons-with-init-scripts
If your script is running on an Ubuntu machine you have the very convenient Upstart, http://upstart.ubuntu.com/
Upstart does a great job running services on boot and respawning a process that died.
I've setup an Amazon EC2 server. I have a Python script that is supposed to download large amounts of data from the web onto the server. I can run the script from the terminal through ssh, however very often I loose the ssh connection. When I loose the connection, the script stops.
Is there a method where I tell the script to run from terminal and when I disconnect, the script is still running on the server?
You have a few options.
You can add your script to cron to be run regularly.
You can run your script manually, and detach+background it using nohup.
You can run a tool such as GNU Screen, and detach your terminal and log out, only to continue where you left off later. I use this a lot.
For example:
Log in to your machine, run: screen.
Start your script and either just close your terminal or properly detach your session with: Ctrl+A, D, D.
Disconnect from your terminal.
Reconnect at some later time, and run screen -rD. You should see your stuff just as you left it.
You can also add your script to /etc/rc.d/ to be invoked on book and always be running.
You can also use nohup to make your script run in the background or when you have disconnected from your session:
nohup script.py &
The & at the end of the command explicitly tells nohup to run your script in the background.
If it just a utility you run ad-hoc, not a service daemon of some kind, i would just run it in screen. Than you can disconnect if you want and open the terminal back up later... Or reconnect the terminal if you get disconnected. It should be in your linux distros package manager. Just search for screen
http://www.gnu.org/software/screen/
nohup runs the given command with hangup signals ignored, so that the command can continue running in the background after you log out.
Syntax:
nohup Command [Arg]...
Example:
nohup example.py
nohup rasa run
Also, you can run scripts continuously using the cron command.
For more:
https://ss64.com/bash/nohup.html
https://opensource.com/article/17/11/how-use-cron-linux