I am developing a python 3.11 program which will run on a few different servers and needs to connect to the local Redis server. On each machine the latter might run on a different port, sometimes the default 6379 but not always.
On the commandline I can issue the following command which on both my Linux and MacOS servers works well:
(base) bob#Roberts-Mac-mini ~ % sudo lsof -n -i -P | grep LISTEN | grep IPv4 | grep redis
redis-ser 60014 bob 8u IPv4 0x84cd01f56bf0ee21 0t0 TCP *:9001 (LISTEN)
What's the better way to get the running port using python functions/libraries?
What if you run your commands within a py script using the os library:
import os
cmd = 'ls -l' <-- change the command you want to run
os.system(cmd)
or else you could also use subprocess library as well:
import subprocess
print(subprocess.check_output(['ls', '-l']))
Restarting the Django server displays the following error:
this port is already running....
This problem occurs specifically on Ubuntu and not other operating systems. How can I free up the port to restart the server?
A more simple solution just type sudo fuser -k 8000/tcp.
This should kill all the processes associated with port 8000.
EDIT:
For osx users you can use sudo lsof -t -i tcp:8000 | xargs kill -9
netstat -ntlp
It will show something like this.
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:8000 0.0.0.0:* LISTEN 6599/python
tcp 0 0 127.0.0.1:27017 0.0.0.0:* LISTEN -
tcp 0 0 192.168.124.1:53 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN -
tcp6 0 0 :::3306 :::* LISTEN
So now just close the port in which Django/python running already by killing the process associated with it.
kill -9 PID
in my case
kill -9 6599
Now run your Django app.
ps aux | grep -i manage
after that you will see all process
ubuntu#ip-10-154-22-113:~/django-apps/projectname$ ps aux | grep -i manage
ubuntu 3439 0.0 2.3 40228 14064 pts/0 T 06:47 0:00 python manage.py runserver project name
ubuntu 3440 1.4 9.7 200996 59324 pts/0 Tl 06:47 2:52 /usr/bin/python manage.py runserver project name
ubuntu 4581 0.0 0.1 7988 892 pts/0 S+ 10:02 0:00 grep --color=auto -i manage
kill -9 process id
e.d kill -9 3440
`enter code here`after that :
python manage.py runserver project name
By default, the runserver command starts the development server on the internal IP at port 8000.
If you want to change the server’s port, pass it as a command-line argument. For instance, this command starts the server on port 8080:
python manage.py runserver 8080
lsof -t -i tcp:8000 | xargs kill -9
Sorry for comment in an old post but It may help people
Just type this on your terminal
killall -9 python3
It will kill all python3 running on your machine and it will free your all port. Greatly help me when to work in Django project.
We don't use this command { sudo lsof -t -i tcp:8000 | xargs kill -9 } Because it's close all tabs...You should use to
ps -ef | grep python
kill -9 process_id
ps -ef | grep python (show all process with id)
kill -9 11633
(11633 is a process id to :- /bin/python manage.py runserver)
>> ps aux | grep manage
ubuntu 3438 127.0.0 2.3 40256 14064 pts/0 T 06:47 0:00 python manage.py runserver
>> kill -9 3438
Type 'fg' as command after that Ctrl-C.
Command:
Fg will show which is running on background. After that Ctrl-C will stop it.
fg
ctl-c
In terminal, Type ps aux | grep runserver
Hit Enter
Use PID among the result execute kill -9 <PID>
For an instance, If result of step 1 is as follow
root 1041 0.0 0.1 266912 34580 pts/3 S+ 11:31 0:01 python3 manage.py runserver 0.0.0.0:3030
root 1696 4.5 0.1 126128 40708 ? S Feb14 925:43 /usr/local/bin/python manage.py runserver 0.0.0.0:8000
1041 and 1696 are PIDs. We need to choose whichever process we want to kill among them.
This is an expansion on Mounir's answer. I've added a bash script that covers this for you. Just run ./scripts/runserver.sh instead of ./manage.py runserver and it'll work exactly the same way.
#!/bin/bash
pid=$(ps aux | grep "./manage.py runserver" | grep -v grep | head -1 | xargs | cut -f2 -d" ")
if [[ -n "$pid" ]]; then
kill $pid
fi
fuser -k 8000/tcp
./manage.py runserver
For me, this happens because my API request in Postman is being intercepted by a debugger breakpoint in my app... leaving the request hanging. If I cancel the request in Postman before killing my app's server, the error does not happen in the first place.
--> So try cancelling any open requests you are making in other programs.
On macOS, I have been using sudo lsof -t -i tcp:8000 | xargs kill -9 when I forget to cancel the open http request in order to solve error = That port is already in use. This also, complete closes my Postman app, which is why my first solution is better.
Click the arrow in the screenshot and find the bash with already running Django server. You were getting the message because your server was already running and you tried to start the server again.
Dont use CTRL + Z to stop server, use CTRL + C to stop the server, I had also had the same problem in my linux (fedora) , I used to stop the server using CTRL + Z and again I used to kill the server using sudo fuser -k 8000/tcp command, which worked fine. But later when I started using CTRL + C , I didnot get that port running issue anymore.
if you have face this problem in mac you just need to open activity monitor and force quite python then try again
In case You are using the VSC's screen terminal, The error might be due to the fact that you already runserver in some other shell.
Just click on the dropbox on the left of the + sign in the header of the terminal of VSC and select some other shell and check if the server is already running there. Quit that server and you are ready to launch a another server.
I was trying all the solutions but they were not working i suggest you to keep press the power button or if your battery is removeable then remove it all the process will be killed and your local host will be reset
I have a text file like below with host, site and port to telnet
Hostname site port
appwlsqa02.comp.xxx.com fgh-fst13-scan.comp.xxx.com 1521
appwlsqa03.comp.xxx.com fgh-fst23-scan.comp.xxx.com 1521
cappwlsqa01.comp.xxx.com fgh-fst13-scan.comp.xxx.com 1521
My goal is to ssh each hostname and execute telnet command
for example for the first row in the file
ssh appwlsqa02.comp.xxx.com
then,
telnet fgh-fst13-scan.comp.xxx.com 1521
I have tried below:
while read HOST site port ; do ssh $HOST "echo exit | telnet $site $port " < /dev/null; done < text.txt`
I have to read hostnames as one variable $HOST and host to check as $site and port as$port
Update:
Here is the script i have developed based on sugegstions:
# /bin/bash
while read HOST site port ;
do
echo $HOST $site $port
ssh -n $HOST "telnet $site $port | grep "Connected" " >> t.txt &
PID=$!
sleep 2
kill "$PID"
if [ -s t.txt ]
then
echo from $HOST to $site $port is open >> succ.txt
else
echo from $HOST to $site $port is closed >> fail.txt
fi
rm t.txt
done < text.txt
When trying to use telnet, you need to run something like expect. Telnet grabs the terminal io. Expect replaces the terminal with a pseudo terminal and allows you to script the input and output.
I have the following TcpDump command written in Python but it doesn't give me any output file with the requested packets although I have TcpDump installed and tested on my Ubuntu VM :
command = 'sudo /usr/sbin/tcpdump -i eth1 {} -c {} -s 0 -w {}'\
.format( 'tcp host 10.0.2.15','30000',
'/home/results/xyz.pcap')
cat test.py
import os
command = '/usr/sbin/tcpdump -i eth1 {} -c {} -s 0 -w {}'.format( 'host 192.168.254.74','30000','res.pcap')
print(command)
os.system(command)
sudo python test.py
/usr/sbin/tcpdump -i eth1 host 192.168.1.10 -c 30000 -s 0 -w res.pcap
tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 10 bytes
^C0 packets captured
6 packets received by filter
0 packets dropped by kernel
ls -l | grep test
-rw------- 1 admin admin 155 Dec 2 23:05 test.py
Seems to work just fine for me.
The test file is 'test.py'. I run it under sudo and exit after some time. I can see that 6 packets were captured and the file size is > 0.
Make sure the command itself runs properly outside of python.
I am installing Hadoop 2.5.0 on a Ubuntu 12.04 cluster, 64-bit. At the end of the instructions I type $ jps on the master node and do not get a NameNode. I checked the Hadoop logs and found:
BindException error stating :9000 is already in use.
$ netstat -a -t --numeric-ports -p | grep :9000 returns that python is listening on this port. It appears I need to move python 2.7 to another port. How do I move python?
Followed the command below, the pid=2346.
$ ps -p 2346
PID TTY TIME CMD
2346 ? 01:28:13 python
Tried second command:
$ ps -lp 2346
F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD
4 S 0 2346 1 0 80 0 - 332027 poll_s ? 01:28:30 python
more detail:
$ ps -Cp 2346
PID TTY STAT TIME COMMAND
2346 ? Ssl 88:34 /usr/lib/cmf/agent/build/env/bin/python /usr/lib/cmf/agent/src/cmf/agent.py --package_dir /usr/lib/cmf
It appears a failed Cloudera Hadoop distribution installation has not been removed. It installed python 2.7 automatically. Not sure what else is automatically running. Will attempt to uninstall python 2.7.
To be clear a program written in python is using port 9000 and not python2.7 itself.
You need to track down this program and then work out how to config it to listen on a different port. You could use this command to get the full details of the process listening on port 9000
netstat -a -t --numeric-ports -p | grep :9000 | awk '{print $7}' | sed -e 's/\/.*//' | xargs echo ps -lp
It appears Cloudera installed python 2.7. This was removed / replace with python 3.2.
The $jps command on Hadoop now returns the expected results including NameNode.