App::RemoteCommand 2018

2018.02.09 kichijojipm 13
(original https://www.slideshare.net/skaji/appremotecommand)

Transcript

1. App::RemoteCommand
   2018.02.09 Shoichi Kaji
   

   View Slide

2. Me
   • Shoichi Kaji
   
   
   • github/PAUSE: skaji
   
   
   • Perl5: cpm
   
   
   • Perl6: mi6
   

   View Slide

3. Contents
   • What is App::RemoteCommand?
   
   
   • Why did I create it?
   
   
   • Features
   
   
   • DEMO
   
   
   • Internals
   

   View Slide

4. What is
   App::RemoteCommand?
   

   View Slide

5. A simple remote command
   launcher via SSH
   

   View Slide

6. Why did I created it?
   • We have a lot of tools that support IT
   automation, such as chef, ansible, capistrano,
   fabric, …
   
   
   • OTOH, we sometimes want to do ad hoc
   operation. Then such IT-automation tools are
   obtrusive. But ssh(1) is powerless.
   
   
   • So I created App::RemoteCommand, which is
   simple, and at the same time, powerful.
   

   View Slide

7. Features
   • Execute remote command in parallel
   
   
   • Remember sudo pass
   fi
   rst, never ask again
   
   
   • You may specify a local script
   fi
   le
   
   
   • Append host and time to each output line
   
   
   • Sane signal handling
   

   View Slide

8. DEMO
   https://asciinema.org/a/119109
   

   View Slide

9. Internals
   • a) Built on top of Net::OpenSSH
   
   
   • b) Using its own event loop
   

   View Slide

10. Built on top of Net::OpenSSH
    • Net::OpenSSH is a wrapper around ssh(1),
    created by Salvador Fandiño.
    
    
    • Because it is a wrapper for ssh(1),
    

    it can use the complicated ~/.ssh/con
    fi
    g 😎
    
    
    • It multiplexes SSH connections.
    
    
    • It provides sophisticated I/F for SSH operation,
    including I/F for event oriented programming.
    

    View Slide

11. Using its own event loop
    • Thanks to Net::OpenSSH, we can easily write an application
    working with SSH in event oriented programming.
    
    
    • In fact, App::RemoteCommand uses its own event loop; it
    watches:
    
    
    • SSH: connected,
    fi
    nished-command, disconnected
    
    
    • IO: readable
    
    
    • Process:
    fi
    nished
    
    
    • Signals: catched
    

    View Slide

12. Try it now!
    
    
    ❯ cpm install -g App::RemoteCommand
    

    View Slide