I am trying to run my flask application on my linux server using nohup , but each time i run my flask application with nohup , my server will require me to kill with cntrl + c in order for me to do other things
assuming i have 2 file in my server
path(home/app/)
flask_app.py [ which is my flask application ]
flk.sh
inside my run.sh i have included
nohup python /home/app/flask_app.py
when i run my shell script in my server which is sh flk.sh
my system will hang as per shown in below image if i dont exit it as its running and all activity will go inside nohup.out
how can i run nohup on my flask application without me having to use cntrl + c to exit to run other commands.
You usually want to use nohup command arg1 arg2 &. You're just missing the ampersand.
Briefly, nohup prevents the OS from killing your job, & sends the job in the background, so it isn't tied to your current shell.
Related
I have a shell script called kill.sh that helps me restart a python script I've written. I normally use pkill -f main.py to kill my forever-running python script. However, when I wrote it into a shell script it does not work.
My script
pkill -f main.py
ps aux | grep main.py # Still shows the process running.
While just executing pkill -f main.py in bash command line works as expected. Why is this?
This is not a satisfactory answer, as I cannot find out the root cause of why pkill -f does not work in a script. I ended up using a systemd Service file to manage my python process. Here's an example fyi.
[Unit]
Description=Service Name
[Service]
Environment=PYTHONUNBUFFERED=1
ExecStart=/path/to/python /path/to/python/script.py
Restart=on-failure
RestartSec=5s
WorkingDirectory=/python/project/dir/
Name the file main.service and place it in /lib/systemd/system/
Running the service systemctl start main.service
Stop the service systemctl stop main.service
Restart the service systemctl restart main.service
Show status and output systemctl status main.service -l
Now I don't have to worry about multiple processes running. If the program dies it'll even restart.
I running python flask as my backend and react as my frontend. Every time I start my app, I have to run export FLASK_APP=app and then flask start in terminal 1 and npm start in terminal 2. How do I write a single script that starts both processes?
Here is my attempt:
#!/bin/bash
export FLASK_APP=microblog.py
flask run > /dev/null
npm start --prefix ~/app
Try this:
#!/bin/bash
export FLASK_APP=microblog.py
flask run > /dev/null & pids=$!
npm start --prefix ~/app & pids+=" $!"
trap "kill $pids" SIGTERM SIGINT
wait $pids
This script starts both flask and npm in background, and stores their PIDs. After that, we set up a trap - in case you hit CTRL - C, both programs will get killed.
The wait line will block until both the flask and npm process has finished - so you can easily terminate both with CTRL-C.
Overview
I'm trying to use python fabric to run an ssh command as root on a remote server.
The command: nohup ./foo &
foo is expected to command run for several days. I must be able to disassociate foo from fabric's remote ssh session, and put foo in the background.
The Fabric FAQ says you should use something like screen or tmux when you run your fabric script (which runs the backgrounded command). I tried that, but my fabric script still hung. foo is not hanging.
Question
How do I use fabric to run this command on a remote server without the script hanging: nohup ./foo &
Details
This is my script:
#!/bin/sh
# Credit: https://unix.stackexchange.com/a/20895/6766
if "true" : '''\'
then
exec "/nfs/it/network_python/$OSREL/bin/python" "$0" "$#"
exit 127
fi
'''
from getpass import getpass
import os
from fabric import Connection, Config
assert os.geteuid()==0, "ERROR: Must run as root"
for host in ['host1.foo.local', 'host2.foo.local']:
# Make an ssh connection to the host...
conn = Connection(host)
# The script always hangs at this line
result = conn.run('nohup ./foo &', warn=True, hide=True)
I always open a tmux session to run the aforementioned script in; even doing so, the script hangs when I get to conn.run(), above.
I'm running the script on a vanilla CentOS 6.5 VM; it runs under python 2.7.10 and fabric 2.1.
The Fabric FAQ is unclear... I thought the FAQ wanted tmux used on the local side when I executed the Fabric script.
The correct way to fix this problem is to replace nohup in the remote command, with screen -d -m <command>. Now I can run the whole script locally with no hangs (and I don't have to use tmux in the local term).
Explicitly, I have to rewrite the last line of my script in my question as:
# Remove &, and nohup...
result = conn.run('screen -d -m ./foo', warn=True, hide=True)
I want to run a python script on boot of ubuntu 14.04LTS.
My rc.local file is as follows:
sudo /home/hduser/morey/zookeeper-3.3.6/bin/zkServer.sh start
echo "test" > /home/hduser/test3
sudo /home/hduser/morey/kafka/bin/kafka-server-start.sh /home/hduser/morey/kafka/config/server.properties &
echo "test" > /home/hduser/test1
/usr/bin/python /home/hduser/morey/kafka/automate.py &
echo "test" > /home/hduser/test2
exit 0
everything except my python script is working fine even the echo statement after running the python script, but the python script doesnt seem to run.
My python script is as follows
import sys
from subprocess import Popen, PIPE, STDOUT
cmd = ["sudo", "./sbt", "project java-examples", "run"]
proc = Popen(cmd, shell=False, stdout=PIPE, stdin=PIPE, stderr=STDOUT)
proc.communicate(input='1\n')
proc.stdin.close()
which works perfectly fine if executed individually.
I went through the following questions , link
I did a lot of research but couldn't find a solution
Edit : echo statements are for testing purpose only, and the second actual command (not considering the echo statements) is starting a server which keeps on running, and even the python script starts a listener which runs on an infinite loop, if this is any help
The Python script tries to launch ./sbt. Are you sure of what if the current directory when rc.local runs? The rule is always use absolute paths in system scripts
Do not run the Python script in background, run it in foreground. Do not exit from its parent script. Better call another script from "rc.local" that does all the job of "echo" and script launching.
Run that script from "rc.local"; not in background (no &).
You do not need "sudo" as "rc.local" is run as root.
If you want to run python script at system boot there is an alternate solution which i have used.
1:Create sh file like sample.sh and copy paste following content
#!/bin/bash
clear
python yourscript.py
2:Now add a cron job at reboot.If you are using linux you can use as following
a:Run crontab -e(Install sudo apt-get install cron)
b:#reboot /full path to sh file > /home/path/error.log 2>&1
And restart your device
we run a django app on our server through this command.
python manage.py runfcgi host=127.0.0.1 port=8070 pidfile=/home/ubuntu/autoleg_webapp/autoleg_clients.pid --settings=PROD_Settings
I have made some changes to PROD_Settings.py file,i want to restart now, how would i do that?
Tour processe's PID is in the pidfile, so you should basically kill this PID.
To do so, execute the following in your shell:
kill `cat /home/ubuntu/autoleg_webapp/autoleg_clients.pid`
Thanks to the backticks, your shell will replace cat home/ubuntu/autoleg_webapp/autoleg_clients.pid with the PID that's in the file.