Class: Aruba::Processes::SpawnProcess

Inherits:
BasicProcess show all
Defined in:
lib/aruba/processes/spawn_process.rb

Overview

Spawn a process for command

‘SpawnProcess` is not meant for direct use - `SpawnProcess.new` - by users. Only it’s public methods are part of the public API of aruba, e.g. ‘#stdin`, `#stdout`.

Instance Attribute Summary

Attributes inherited from BasicProcess

#environment, #exit_status, #exit_timeout, #io_wait_timeout, #main_class, #startup_wait_time, #stop_signal, #working_directory

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from BasicProcess

#after_run, #arguments, #before_run, #command, #commandline, #empty?, #inspect, #output, #restart, #started?, #stopped?, #timed_out?

Constructor Details

#initialize(cmd, exit_timeout, io_wait_timeout, working_directory, environment = Aruba.platform.environment_variables.hash_from_env, main_class = nil, stop_signal = nil, startup_wait_time = 0) ⇒ SpawnProcess

Create process

Parameters:

  • cmd (String) —

    Command string

  • exit_timeout (Numeric) —

    The timeout until we expect the command to be finished

  • io_wait_timeout (Numeric) —

    The timeout until we expect the io to be finished

  • working_directory (String) —

    The directory where the command will be executed

  • environment (Hash) (defaults to: Aruba.platform.environment_variables.hash_from_env) —

    Environment variables

  • main_class (Class) (defaults to: nil) —

    E.g. Cli::App::Runner

  • stop_signal (String) (defaults to: nil) —

    Name of signal to send to stop process. E.g. ‘HUP’.

  • startup_wait_time (Numeric) (defaults to: 0) —

    The amount of seconds to wait after Aruba has started a command.



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# File 'lib/aruba/processes/spawn_process.rb', line 131

def initialize(cmd, exit_timeout, io_wait_timeout, working_directory, # rubocop:disable Metrics/ParameterLists
               environment = Aruba.platform.environment_variables.hash_from_env,
               main_class = nil, stop_signal = nil, startup_wait_time = 0)
  super

  @process      = nil
  @stdout_cache = nil
  @stderr_cache = nil
end

Class Method Details

.match?(_mode) ⇒ Boolean

Use as default launcher

Returns:

  • (Boolean) 


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# File 'lib/aruba/processes/spawn_process.rb', line 102

def self.match?(_mode)
  true
end

Instance Method Details

#close_io(name) ⇒ Object

Close io



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# File 'lib/aruba/processes/spawn_process.rb', line 245

def close_io(name)
  return if stopped?

  @process.public_send(name.to_sym).close
end

#content ⇒ String

Content of command

Returns:

  • (String) —

    The content of the script/command. This might be binary output as string if your command is a binary executable.



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# File 'lib/aruba/processes/spawn_process.rb', line 327

def content
  File.read command_path
end

#filesystem_status ⇒ Aruba::Platforms::FilesystemStatus

Return file system stats for the given command

Returns:



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# File 'lib/aruba/processes/spawn_process.rb', line 318

def filesystem_status
  Aruba.platform.filesystem_status.new(command_path)
end

#interactive? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/aruba/processes/spawn_process.rb', line 331

def interactive?
  true
end

#pid ⇒ Object

Output pid of process

This is the PID of the spawned process.



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# File 'lib/aruba/processes/spawn_process.rb', line 297

def pid
  @process.pid
end

#send_signal(signal) ⇒ Object

Send command a signal

Parameters:

  • signal (String) —

    The signal, i.e. ‘TERM’



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# File 'lib/aruba/processes/spawn_process.rb', line 305

def send_signal(signal)
  error_message = %(Command "#{commandline}" with PID "#{pid}" has already stopped.)
  raise CommandAlreadyStoppedError, error_message if @process.exited?

  Process.kill signal, pid
rescue Errno::ESRCH
  raise CommandAlreadyStoppedError, error_message
end

#start {|SpawnProcess| ... } ⇒ Object

Run the command

Yields:



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# File 'lib/aruba/processes/spawn_process.rb', line 146

def start
  if started?
    error_message =
      "Command \"#{commandline}\" has already been started. " \
      'Please `#stop` the command first and `#start` it again. ' \
      'Alternatively use `#restart`.'
    raise CommandAlreadyStartedError, error_message
  end

  @started = true

  @process = ProcessRunner.new(command_string.to_a)

  @stdout_file = Tempfile.new('aruba-stdout-')
  @stderr_file = Tempfile.new('aruba-stderr-')

  @stdout_file.sync = true
  @stderr_file.sync = true

  @stdout_file.set_encoding('ASCII-8BIT')
  @stderr_file.set_encoding('ASCII-8BIT')

  @exit_status = nil

  before_run

  @process.stdout = @stdout_file
  @process.stderr = @stderr_file
  @process.cwd    = @working_directory

  @process.environment = environment

  begin
    @process.start
    sleep startup_wait_time
  rescue SystemCallError => e
    raise LaunchError, "It tried to start #{commandline}. " + e.message
  end

  after_run

  yield self if block_given?
end

#stderr(opts = {}) ⇒ String

Access to stderr of process

Parameters:

  • opts (Hash) (defaults to: {}) —

    Options

  • [Integer] (Hash) —

    a customizable set of options

Returns:

  • (String) —

    The content of stderr



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# File 'lib/aruba/processes/spawn_process.rb', line 226

def stderr(opts = {})
  return @stderr_cache if stopped?

  wait_for_io opts.fetch(:wait_for_io, io_wait_timeout) do
    @process.stderr.flush
    open(@stderr_file.path).read
  end
end

#stdin ⇒ Object

Access to stdin of process



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# File 'lib/aruba/processes/spawn_process.rb', line 191

def stdin
  return if @process.exited?

  @process.io.stdin
end

#stdout(opts = {}) ⇒ String

Access to stdout of process

Parameters:

  • opts (Hash) (defaults to: {}) —

    Options

  • [Integer] (Hash) —

    a customizable set of options

Returns:

  • (String) —

    The content of stdout



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# File 'lib/aruba/processes/spawn_process.rb', line 207

def stdout(opts = {})
  return @stdout_cache if stopped?

  wait_for_io opts.fetch(:wait_for_io, io_wait_timeout) do
    @process.stdout.flush
    open(@stdout_file.path).read
  end
end

#stop ⇒ Object

Stop command



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# File 'lib/aruba/processes/spawn_process.rb', line 252

def stop(*)
  return @exit_status if stopped?

  @process.poll_for_exit(@exit_timeout) or @timed_out = true

  terminate
end

#terminate ⇒ Object

Terminate command



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# File 'lib/aruba/processes/spawn_process.rb', line 266

def terminate
  return @exit_status if stopped?

  unless @process.exited?
    if @stop_signal
      # send stop signal ...
      send_signal @stop_signal
      # ... and set the exit status
      wait
    else
      begin
        @process.stop
      rescue Errno::EPERM # This can occur on MacOS
        nil
      end
    end
  end

  @exit_status = @process.exit_code

  @stdout_cache = read_temporary_output_file @stdout_file
  @stderr_cache = read_temporary_output_file @stderr_file

  @started = false

  @exit_status
end

#wait ⇒ Object

Wait for command to finish



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# File 'lib/aruba/processes/spawn_process.rb', line 261

def wait
  @process.wait
end

#write(input) ⇒ Object 



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# File 'lib/aruba/processes/spawn_process.rb', line 235

def write(input)
  return if stopped?

  @process.stdin.write(input)
  @process.stdin.flush

  self
end