Chee

A Ruby gem that allows interactive User <-> Ruby <-> SSH sessions. It uses Net::SSH and a pseudo-terminal.

Thanks

This post by jtzero provided the solution for using STDIN and Net::SSH: http://stackoverflow.com/questions/6942279/ruby-net-ssh-channel-dies

Limitations

  • Programs that redraw the screen (e.g. vim) don't work that well. Apt-get and other programs that request input in a simple manner should work well enough.

  • A pseudo-terminal is used. Which means it runs in a sub-shell. Which leads to no STDERR access. All returning output from your command is done on STDOUT.

Installation

gem install Chee

Usage: DSL

You could include the DSL into your own object:

require "Chee"
Class My_SSH
  include Chee::DSL
end

o = My_SSH.new
o.server 'my_server'
o.ssh "uptime"

Or you could use Chee directly:

require "Chee"
Chee.server 'my_server'
Chee.ssh "uptime"

:server accepts the same options as Net::SSH.start:

Chee.server(
  'localhost', 
  'me', 
  :password => "try to use private/public keys", 
  :timeout  => 3  
)

:ssh returns a Chee::Result object:

result = Chee.ssh( "uptime" )
result.out         # ==> output from STDOUT
result.exit_status

Usage: Printing Output

Override default printing with :print_data:

def print_data data
  # ignore data
end

# The default is:
def print_data data
  print data   
  STDOUT.flush
end

You can still get the output with the returned value of :ssh or :ssh_to_all:

o.ssh( "uptime" ).out

o.ssh_to_all("uptime").map(&:out)

Usage: Single Server

require "Chee"

Chee.server "my_server"  

Chee.ssh %^ sudo add-apt-repository ppa:nginx/stable ^

Usage: Multiple Servers

Chee.server 'server_1'
Chee.server 'server_2', 'my_username'

Chee.ssh_to_all "uptime"
# --->  [ Chee::Result, Chee::Result ]

Usage: Multiple Line Command

Single Server, multiple commands:

Chee.server 'localhost'

Chee.ssh %^

  sudo add-apt-repository ppa:nginx/stable
  sudo apt-get install nginx

^
# ---> [ Chee::Result, Chee::Result ]

Multiple servers, multiple commands:

Chee.server 'localhost'
Chee.server 'my_other_host'

Chee.ssh_to_all('
  echo "a"
  echo "b"
')
.map(&:out)

# ---> [ "a", "b", "a", "b" ]

Run Tests

To run the tests:

git clone git@github.com:da99/Chee.git
cd Chee
bundle update
bundle exec bacon spec/main.rb

The tests assume you use passwordless SSH login using private keys and put the following in your ~/.ssh/config:

Host localhost
  User *your username*
  IdentityFile ~/.ssh/path_to_priv_key

The following is useful for Ubuntu users:

sudo apt-get install ufw openssh-server
sudo ufw allow from 127.0.0.1 to any port 22
sudo ufw deny ssh
sudo ufw default deny
sudo ufw enable

"I hate writing."

If you know of existing software that makes the above redundant, please tell me. The last thing I want to do is maintain code.