How to run a terminal command using python script, which is held through wsgi process? - apache

Question

I have a Centos 7 server with cPanel and I'm working on a Telegram bot for my business needs. The bot should be able to run a terminal command with os.system or subprocess.Popen, however both options do not work when configured through a webhook + wsgi process.
I tested both with bot.polling method and they worked as a charm, however after I switched to webhook method served by flask and wsgi, both stopped working for me. I have tried the following:
mycommand = "python3.6 GoReport.py --id 31-33 --format word"
os.chdir('dir_to_run_command_from')
os.system(mycommand)
and the following one:
mycommand = "python3.6 GoReport.py --id 31-33 --format word"
subprocess.Popen(mycommand, cwd="dir_to_run_command_from", shell=True)
Both options simply do nothing right now. I tried to print them both and received 0 as a response. I wonder if the issue is caused by permissions or something.
I expect both options to work through webhook + wsgi as good as they work through bot.polling method.

Answer 1

I think I got it wrong. Your script writes a report to a specific directory. You do not need a result in your application route.
I wrote a small test application called tryout. It runs in a virtual environment.
$ mkdir tryout
$ cd tryout
$ python3 -m venv tryout
$ source tryout/bin/activate
$ export FLASK_APP=tryout/app
$ export FLASK_ENV=development
$ flask run
Directory structure:
/tryout
/app/*
/bin/*
/include/*
/lib/*
/subdir/*
Application:
# /tryout/app/__init__.py
import sys, os
from flask import Flask
def create_app(env=os.getenv('FLASK_ENV', 'development')):
app = Flask(__name__)
#app.route('/run-script')
def run_script():
import subprocess
cmd = 'python script.py'
cwd = 'subdir'
ret = subprocess.check_output(cmd, cwd=cwd, shell=True)
print(ret)
return ret, 200
return app
app = create_app()
Script:
# /subdir/script.py
import os, sys
def main():
with open('report.txt', 'w+') as fp:
fp.write('Info\n')
sys.stdout.write('It works!')
if __name__ == '__main__':
main()
It works!
A new file named "report.log" is written into the "subdir"-directory.
In Browser appears "It works!".
Hope I could help you or I have no real idea of what you want to do.

Answer 2

If you want to run an external script from inside flask, you could use subprocess to run the script from the command line. This is the right solution.
#app.route('/run-script')
def run_script():
cmd = '<your command here!>'
result = subprocess.check_output(cmd, cwd='<your wordir>', shell=True)
return render_template('results.html', **locals())
Have fun!

Answer 3

#Bogdan Kozlowskyi
Is it possible to pipe on the command line? Do you need to return a result to the user?
cmd = 'first_cmd | tee report.log'
result = subprocess.check_output(cmd, cwd='<your wordir>', shell=True)
Perhaps you should look for shell commands like '>>', '>' and 'tee'.

Answer 4

Seems to be a user-groups permission problem (execute and write).