Knocker

I wanted to use knock servers but wasn't sure how to remember all the knock patterns, plus I pretty much always want to run specific commands straight after knocking.

I also love .ssh/config files (if you don't use one, you are missing out!), so simple yet so powerful.

Installation

Add this line to your application's Gemfile:

gem 'knocker'

And then execute:

$ bundle

Or install it yourself as:

$ gem install knocker

Usage

Like an SSH config is powerful for connecting to SSH daemons:

# SSH config file
Host myvps
  Hostname vps.example.com
  User robert
  Port 22022
  DynamicForward 50000
  LocalForward 3000:localhost:3000
  ForwardX11 yes

I want knocker to be powerful for connecting to knock daemons:

Each config file stores knock patterns which include:

hostname
knock specs
commands to run after knocking

# Knocker config file
# keep this secret, knock patterns are almost like passwords
pattern pvtchatops
  host myvps.example.com
  u 5445
  t 4456
  t 63854
  c xchat --url=irc://$host:36777/chatops

So when you run nkr pvtchatops it actually runs two commands:

The knock client command: knock myvps.example.com 5445:udp 4456:tcp 63854:tcp
The post command: xchat --url=irc://myvps.example.com:36777/chatops

Easy!

The rules

As you saw, the config syntax is simple.

use pattern and a name to name the pattern
h and then the hostname/ip to connect to
t and the port number for a tcp knock (multiples allowed)
u and the port number for a udp knock (multiples allowed)
c and the command to run after knocking (multiples allowed)
on command lines use $host to use host defined for the pattern

Mix this with SSH config files and you will an unstoppable sysadmin!

KEEP THE CONFIG FILE SECRET!!!

Contributing

Fork it ( http://github.com/penguinpowernz/knocker/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request