namespace :ssh do
  desc "Install your public key on a remote server."
  task :install_public_key do
    begin
      require 'rubygems'
      require 'net/ssh'
      require 'net/scp'
      require 'highline'
    rescue LoadError
      abort "There was a problem loading net-ssh, net-scp, or highline.  Please make sure you have them installed via RubyGems."
    end
 
    unless discovered_key = %w[id_rsa id_dsa identity].detect { |f| File.exists?("#{ENV['HOME']}/.ssh/#{f}.pub") }
      abort <<-EOS
I wasn't able to discover your public key.  I tried to find id_rsa.pub, id_dsa.pub,
or identity.pub in "#{ENV['HOME']}/.ssh".  You can hard code the path to the file by 
passing public_key_path via the command line.
        EOS
    end
 
    h = HighLine.new
    not_blank = Proc.new { |s| !s.empty? }
    def not_blank.to_s; "not blank"; end
    h.say "I need some information to SSH into the server."
    hostname = h.ask("Remote Hostname: ") { |q| q.validate = not_blank }
    username = h.ask("Username, enter for default: ") { |q| q.default = ENV["USER"] }
    password = h.ask("Password: ") { |q| q.echo = "*" }
    public_key_path = "#{ENV['HOME']}/.ssh/#{discovered_key}.pub"
    
    begin
      Net::SSH.start(hostname, username, :password => password) do |ssh|
        puts "Uploading your public key... "
        ssh.scp.upload! public_key_path, "my_public_key"
 
        puts "Creating '.ssh' directory in your home directory"
        ssh.exec!("mkdir .ssh")
 
        puts "Concatenating your public key into the authorized_keys file"
        ssh.exec!("cat my_public_key >> .ssh/authorized_keys")
 
        puts "Removing your public key"
        ssh.exec!("rm my_public_key")
 
        puts "Setting permissions on .ssh"
        ssh.exec!("chmod 700 .ssh")
 
        puts "Setting permissions on your authorized_keys file"
        ssh.exec!("chmod 600 .ssh/authorized_keys")
 
        puts "\nAll done!  Enjoy your new, potentially password-free login."
      end
    rescue Net::SSH::AuthenticationFailed
      puts "\nWhat we've got here... is a failure to communicate.  There was a problem authenticating you."
    end
  end
end