Net::SSH sudo command hangs after entering password

Question

I\'ve been trying to write a small library using Thor to help assist me in quick creating new projects and sites. I wrote this small method:

def ssh(cmd)
           


        

Answer 1

Actually in the end, I did something very similar to Riba's suggestion (although his/her code is much better and smarter, I think)

def ssh(env, cmd, opts={})
    Net::SSH.start( config[env]["ip"], config[env]["user"], :port => config[env]["port"]) do |session|
        cmd = "sudo #{cmd}" if opts[:sudo]
        print cmd
        session.exec cmd
    end
end

Answer 2

I cheated by doing adding this:

sudouser  ALL=(ALL:ALL) NOPASSWD: ALL

to /etc/sudoers

Also, be sure to use visudo when editing!!!

Answer 3

It's possible to set it up with net/ssh, but it's really too much effort, just execute ssh command like this:

system("ssh", "-t", "#{user}@#{host}", "sudo cp #{file_from_path} #{file_to_path}")

This -t means to allocate a tty. Without it it will still work, but your password will be seen in clear.

(I assume you intend to type sudo password manually. If not, go the authorized keys way).

Answer 4

Here is a possible solution :

def ssh(cmd)
  Net::SSH.start( server_ip, user, :port => port) do |session|
    result = nil
    session.exec!(cmd) do |channel, stream, data|
      if data =~ /^\[sudo\] password for user:/
        channel.send_data 'your_sudo_password'
      else
        result << data
      end
    end
    result # content of 'cmd' result
  end
end

But with this solution, you have your root password writen in clear in a script file somewhere ...

Answer 5

I hope this will help someone searching. I also needed to sudo during deployment (restarting thin instances)

# deploy.rake
require 'net/ssh'

# INITIALIZE CONSTANTS HERE
HOST = 'yourwebsite.com'
USER = 'admin'
PASSWORD = 'your server password' # or use ENV variables?
# etc.

namespace :deploy do 
  namespace :staging do  
    task :restart do
      commands = [
        "cd #{PATH_TO_STAGING_APP} && git checkout master",
        "git reset --hard HEAD",
        "git pull origin master",
        "bundle install --without test development",
        "sudo thin restart -C /etc/thin/#{STAGING_APP}.yml"
      ]

      Net::SSH.start(HOST, USER, :password => PASSWORD) do |ssh|
        ssh.open_channel do |channel|
          channel.request_pty do |ch, success|
            if success
              puts "Successfully obtained pty"
            else
              puts "Could not obtain pty"
            end
          end

          channel.exec(commands.join(';')) do |ch, success|
            abort "Could not execute commands!" unless success

            channel.on_data do |ch, data|
              puts "#{data}"
              channel.send_data "#{PASSWORD}\n" if data =~ /password/
            end

            channel.on_extended_data do |ch, type, data|
              puts "stderr: #{data}"
            end

            channel.on_close do |ch|
              puts "Channel is closing!"
            end
          end
        end
        ssh.loop
      end
    end
  end
end

Note that one channel can only execute one command. Hence I chained the commands together with commands.join(';')

Reference: Net::SSH::Connection::Channel

Answer 6

The first thing you might want to try is using public keys instead of passwords to login. Then also try running the command from the interactive shell.

For example:

(This part really depends on the server/client software you have)

$ ssh-keygen
$ scp .ssh/id-dsa.pub server:
$ ssh server
server$ cat id-dsa.pub >> .ssh/authorizedkeys

$ scp -c "ls"

this should work without any prompts, if the key sharing was successful.