App::RemoteCommand is a simple remote command launcher via SSH. It was created because existing IT automation tools can be obtrusive for ad hoc operations, while SSH alone lacks power. Key features include executing commands in parallel on multiple hosts, remembering sudo passwords, specifying local script files, and appending host/time to output. It is built on Net::OpenSSH for its SSH capabilities and uses its own event loop to monitor SSH connections and processes.

1. App::RemoteCommand
2018.02.09 Shoichi Kaji

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

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

4. What is
App::RemoteCommand?

5. A simple remote command
launcher via SSH

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.

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

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

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

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/config 😎
• It multiplexes SSH connections.
• It provides sophisticated I/F for SSH operation,
including I/F for event oriented programming.

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, finished-command, disconnected
• IO: readable
• Process: finished
• Signals: catched

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