Update 2013-06-14: Improved the script, removing the github-auth dependency, some of the OS X dependencies, and added firewall punch-through (user specific) and ssh-command with external IP auto-copy to clipboard

I wanted a quick and easy way to set up a new TMUX session with a brand new pair, so I came up with this:

#!/bin/sh
gh-auth add $1
sudo cp ~/.ssh/authorized_keys /Users/pair/.ssh/authorized_keys
sudo chown pair:staff /Users/pair/.ssh/authorized_keys
gh-auth remove $1
tmux -S /tmp/pairing new -ds pairing && chgrp staff /tmp/pairing && tmux -S /tmp/pairing attach -t pairing
sudo rm -f /Users/pair/.ssh/authorized_keys

That will download ssh keys, create a tmux session, and attach to it. When you’re done it will cleanup so the other person has no access to your box.

And I have a pair-session script in the /Users/pair/bin directory that looks like this:

#!/bin/sh
tmux -S /tmp/pairing attach -t pairing

Usage

You can invoke the host one like this: pair-session marksim (replacing marksim with whatever github user you want to pair with)

And your pair simply has to type pair-session to connect.

Requirements

  • github-auth gem (which requires Ruby 1.9)
  • ability to sudo
  • a user called ‘pair’ that has SSH (a.k.a. Remote-Login on OS X) enabled
  • an editor that works in the terminal :)

Positives

  • The user does not have access to your files since they’re not SSHing in as you
  • No need to install a system wide RVM or Ruby 1.9 for github-auth – this copies the .ssh/authorized_keys into your pair account
  • Besides creating a user, you can have a TMUX-ready pair session with a brand new pair ready in under 10 seconds.
  • Automatically de-authorized the user once you’re done.

Negatives

  • I wish it didn’t have to copy authorized_keys – maybe it’s worth hacking to not require github-auth?
  • It requires a sudo password – and can require it twice if your session goes on long enough.
  • Currently, specific to OS X (/Users/, and the ‘staff’ group)

Anyway, I hope it’s useful to others as a simple way to set up your box for pairing.