Kill localhost process on specific port

When I’m developing this website I got this message every time I run gatsby develop command.

Something is already running at port 8000
? Would you like to run the app at another port instead? > (Y/n)

Since it’s rather annoying to press y everytime I want to build it, I learn one trick on how to kill process on localhost with specific port

First, I need to find which process running on port 8000. I can use this command:

lsof -i :8000

lsof is a command find opened files, socket or network according to Linux man page.

I get the following output.

COMMAND   PID   USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
node    23560 nakama  212u  IPv4 0x6664bdf40d2e27b7      0t0  TCP localhost:irdmi (LISTEN)
node    23560 nakama  222u  IPv4 0x6664bdf410386657      0t0  TCP localhost:irdmi->localhost:64396 (CLOSED)
node    23560 nakama  224u  IPv4 0x6664bdf3d078f7b7      0t0  TCP localhost:irdmi->localhost:65170 (CLOSE_WAIT)

Since there’s one PID running on port 8000, I could kill it using

kill -9 23560