Class: Train::Extras::LinuxCommand

Inherits:
CommandWrapperBase show all
Defined in:
lib/train/extras/command_wrapper.rb

Overview

Wrap linux commands and add functionality like sudo.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(backend, options) ⇒ LinuxCommand

Returns a new instance of LinuxCommand.



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# File 'lib/train/extras/command_wrapper.rb', line 41

def initialize(backend, options)
  @backend = backend
  validate_options(options)

  @shell         = options[:shell]
  @shell_options = options[:shell_options] # e.g. '--login'
  @shell_command = options[:shell_command] # e.g. '/bin/sh'
  @sudo          = options[:sudo]
  @sudo_options  = options[:sudo_options]
  @sudo_password = options[:sudo_password]
  @sudo_command  = options[:sudo_command]
  @user          = options[:user]
end

Instance Attribute Details

#backend ⇒ Object (readonly)

Returns the value of attribute backend.



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# File 'lib/train/extras/command_wrapper.rb', line 39

def backend
  @backend
end

Class Method Details

.active?(options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/train/extras/command_wrapper.rb', line 104

def self.active?(options)
  options.is_a?(Hash) && (
    options[:sudo] ||
    options[:shell]
  )
end

Instance Method Details

#run(command) ⇒ Object 



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# File 'lib/train/extras/command_wrapper.rb', line 100

def run(command)
  shell_wrap(sudo_wrap(command))
end

#verify ⇒ Object 



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# File 'lib/train/extras/command_wrapper.rb', line 56

def verify
  # Do nothing, successfully. Don't use "true", that's not available on Windows.
  cmd = if @sudo
          # Wrap it up. It needs /dev/null on the outside to disable stdin
          "sh -c '(#{run("echo")}) < /dev/null'"
        else
          run("echo")
        end

  # rubocop:disable Style/BlockDelimiters
  res = @backend.with_sudo_pty {
    @backend.run_command(cmd)
  }
  return nil if res.exit_status == 0

  rawerr = "#{res.stdout} #{res.stderr}".strip

  case rawerr
  when /Sorry, try again/
    ["Wrong sudo password.", :bad_sudo_password]
  when /sudo: no tty present and no askpass program specified/
    ["Sudo requires a password, please configure it.", :sudo_password_required]
  when /sudo: command not found/
    ["Can't find sudo command. Please either install and "\
      "configure it on the target or deactivate sudo.", :sudo_command_not_found]
  when /sudo: sorry, you must have a tty to run sudo/
    ["Sudo requires a TTY. Please see the README on how to configure "\
      "sudo to allow for non-interactive usage.", :sudo_no_tty]
  when /sudo: a terminal is required to read the password; either use/
    ["Sudo cannot prompt for password because there is no terminal. "\
        "Please provide the sudo password directly", :sudo_missing_terminal]
  else
    [rawerr, nil]
  end
end

#verify! ⇒ Object

Raises:



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# File 'lib/train/extras/command_wrapper.rb', line 92

def verify!
  msg, reason = verify
  return nil unless msg

  raise Train::UserError.new("Sudo failed: #{msg}", reason)
end