class SSH

SSH provides a simple streaming ssh command runner. That's it. This is a one trick pony.

ssh = SSH.new "example.com", "/var/log"
puts ssh.run "ls"

SSH was extracted from rake-remote_task which was extracted from vlad.

SSH's idea contributed by Joel Parker Henderson.

Constants

VERSION

Attributes

ssh_cmd[RW]

ssh_flags[RW]

sudo_password[RW]

sudo_prompt[RW]

target_dir[RW]

target_host[RW]

Public Class Methods

new(target_host = nil, target_dir = nil) click to toggle source

# File lib/ssh.rb, line 32
def initialize target_host = nil, target_dir = nil
  self.ssh_cmd       = "ssh"
  self.ssh_flags     = []
  self.target_host   = target_host
  self.target_dir    = target_dir

  self.sudo_prompt   = /^Password:/
  self.sudo_password = nil
end

Public Instance Methods

empty_streams(pid, inn, out, err) click to toggle source

# File lib/ssh.rb, line 68
def empty_streams pid, inn, out, err
  result  = []
  inn.sync   = true
  streams    = [out, err]
  out_stream = {
    out => $stdout,
    err => $stderr,
  }

  # Handle process termination ourselves
  status = nil
  Thread.start do
    status = Process.waitpid2(pid).last
  end

  until streams.empty? do
    # don't busy loop
    selected, = select streams, nil, nil, 0.1

    next if selected.nil? or selected.empty?

    selected.each do |stream|
      if stream.eof? then
        streams.delete stream if status # we've quit, so no more writing
        next
      end

      data = stream.readpartial(1024)
      out_stream[stream].write data

      if stream == err and data =~ sudo_prompt then
        inn.puts sudo_password
        data << "\n"
        $stderr.write "\n"
      end

      result << data
    end
  end

  return status, result
end

run(command) click to toggle source

# File lib/ssh.rb, line 42
def run command
  command = "cd #{target_dir} && #{command}" if target_dir
  cmd     = [ssh_cmd, ssh_flags, target_host, command].flatten

  if $DEBUG then
    trace = [ssh_cmd, ssh_flags, target_host, "'#{command}'"]
    warn trace.flatten.join ' '
  end

  pid, inn, out, err = popen4(*cmd)

  status, result = empty_streams pid, inn, out, err

  unless status.success? then
    e = status.exitstatus
    c = cmd.join ' '
    raise(CommandFailedError.new(status), "Failed with status #{e}: #{c}")
  end

  result.join
ensure
  inn.close rescue nil
  out.close rescue nil
  err.close rescue nil
end