Get python process ID for a flask web site and/or port number?

rhel python kill nohup

8,410

Solution 1

You can use lsof to find the process id associated with a known port number

lsof -i :*port*

Alternatively, you may wish to use netstat which can display all network connections, routing tables, interface statistics, masquerade connections, and multicast memberships.

Try netstat -tulpn

Solution 2

One other way is to add it to the flask app itself.

from os import getpid
print("Creating PID file.")
fh=open("/var/run/yourAppNameWithPort.pid", "w")
fh.write(str(getpid()))
fh.close()

8,410

Unknown Coder

Updated on September 18, 2022

Comments

Unknown Coder over 1 year
I have some web applications that I wrote with python flask. I know which port I started each one on and each was started using nohup. Each one was started with something like nohup python mywebapp.py &

When I look at my processes with ps, I only see something like
```
36697 ?        60-21:36:16 python
 36971 ?        63-19:11:43 python
 37038 ?        65-06:57:22 python
 37312 ?        54-23:33:16 python
 37442 ?        54-09:14:57 python
 37716 ?        47-19:45:17 python
 68019 ?        00:29:24 python
146568 ?        00:20:57 python
146699 ?        00:17:08 python
150622 ?        00:32:20 python
```
If I need to stop one particular web application, how can I get from a port number back to a python process id so that I can kill the process?
- Jeff Schaller almost 6 years
  
  where does the port number get specified when you start(ed) them?
- Unknown Coder almost 6 years
  
  @JeffSchaller Great question, that is specified within the python code, specifically with a call to start an app server with the flask library/framework.
- Jeff Schaller almost 6 years
  
  So the parameter mywebapp.py is enough to determine the port?
Unknown Coder almost 6 years

This sounds like its along the right track but this server does not have lsof and I cant use apt-get. Are there any other commands similar to this that you would recommend?
Unknown Coder almost 6 years

Is this something I would do before I startup the app or can I do it even while the app is running?
Tyler Chambers almost 6 years

if you have netstat you may be able to find it using netstat -tulpn. You may have to grep the output for it to be useful.
Unknown Coder almost 6 years

That did it, thank you! I can see the ports and then it gives me the PID in the last column, this is perfect!
Joe M almost 6 years

You'd add this to you app, it would happen on startup. I usually use argparse and pass in the pidfile name as an argument, but that is just my preference.