ruby running commands on a remote machine

Question

I'm trying to run commands remotely with ruby's net ssh. I need the output as well as the exit code. There are other stackoverflow threads on this topic but the accepted solutions do not work. Some people suggested using net-ssh-shell gem but as I tried it, I got an error saying that this package is in conflict with the version of my net-ssh package... Here is what I have:

  Net::SSH.start(remote_ip, username,:keys => [ssh_key_path], :verbose => :debug) do |ssh|
    cmd = "blah bla"
    result = ssh.exec!(cmd)
    puts result
  end

It works but it does not raise an exception if it fails. I've also tried using the channel to retrieve the exit code but it always returns 0:

channel.on_request("exit-status") do |ch,data|
  exit_code = data.read_long
end

Please help me out. I've already tried several things based on wrong info on the internet.

Answer 1

If you are using Ruby 1.9+ I would suggest Open3.popen3:

i, o, e, t = Open3.popen3("ssh ... remote_user@remote_host remote_command")
i.write ... # if your command needs input
output = o.read
error = e.read
status = t.value.exitstatus