[Rails] Port佔用問題 - Address already in use - bind(2) (Errno::EADDRINUSE)

錯誤訊息

開啟的時候發現port被佔用

$ rails s
=> Booting Puma
=> Rails 5.1.0.rc1 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.8.2 (ruby 2.3.1-p112), codename: Sassy Salamander
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Exiting
/Users/XinYing/.rvm/gems/ruby-2.3.1/gems/puma-3.8.2/lib/puma/binder.rb:269:in `initialize': Address already in use - bind(2) for "0.0.0.0" port 3000 (Errno::EADDRINUSE)

處理方式

先查佔用該port的PID

這邊舉例port3000

$ lsof -i tcp:3000 
#OMMAND   PID    USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
#ruby    28143 ANXGANG   19u  IPv4 0xaacecc8b906857cf      0t0  TCP *:hbci (LISTEN)

根據PID強制刪除

$ kill -9 28143

備註

雖然是月經文，但因為指令實在太難記，特別紀錄下：

• lsof： list open files
• -i: select IPv[46] files

參考

1. http://stackoverflow.com/questions/31039998/address-already-in-use-bind2-errnoeaddrinuse