class Aruba::Processes::SpawnProcess

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`.

@private

Public Class Methods

match?(_mode) click to toggle source

Use as default launcher

# File lib/aruba/processes/spawn_process.rb, line 100
def self.match?(_mode)
  true
end
new(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) click to toggle source

Create process

@param [String] cmd

Command string

@param [Numeric] exit_timeout

The timeout until we expect the command to be finished

@param [Numeric] io_wait_timeout

The timeout until we expect the io to be finished

@param [String] working_directory

The directory where the command will be executed

@param [Hash] environment

Environment variables

@param [Class] main_class

E.g. Cli::App::Runner

@param [String] stop_signal

Name of signal to send to stop process. E.g. 'HUP'.

@param [Numeric] startup_wait_time

The amount of seconds to wait after Aruba has started a command.
Calls superclass method Aruba::Processes::BasicProcess::new
# File lib/aruba/processes/spawn_process.rb, line 129
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

Public Instance Methods

close_io(name) click to toggle source

Close io

# File lib/aruba/processes/spawn_process.rb, line 243
def close_io(name)
  return if stopped?

  @process.public_send(name.to_sym).close
end
content() click to toggle source

Content of command

@return [String]

The content of the script/command. This might be binary output as
string if your command is a binary executable.
# File lib/aruba/processes/spawn_process.rb, line 325
def content
  File.read command_path
end
filesystem_status() click to toggle source

Return file system stats for the given command

@return [Aruba::Platforms::FilesystemStatus]

This returns a File::Stat-object
# File lib/aruba/processes/spawn_process.rb, line 316
def filesystem_status
  Aruba.platform.filesystem_status.new(command_path)
end
interactive?() click to toggle source
# File lib/aruba/processes/spawn_process.rb, line 329
def interactive?
  true
end
pid() click to toggle source

Output pid of process

This is the PID of the spawned process.

# File lib/aruba/processes/spawn_process.rb, line 295
def pid
  @process.pid
end
send_signal(signal) click to toggle source

Send command a signal

@param [String] signal

The signal, i.e. 'TERM'
# File lib/aruba/processes/spawn_process.rb, line 303
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() { |self| ... } click to toggle source

Run the command

@yield [SpawnProcess]

Run code for process which was started
# File lib/aruba/processes/spawn_process.rb, line 144
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 = {}) click to toggle source

Access to stderr of process

@param [Hash] opts

Options

@option [Integer] wait_for_io

Wait for IO to be finished

@return [String]

The content of stderr
# File lib/aruba/processes/spawn_process.rb, line 224
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() click to toggle source

Access to stdin of process

# File lib/aruba/processes/spawn_process.rb, line 189
def stdin
  return if @process.exited?

  @process.io.stdin
end
stdout(opts = {}) click to toggle source

Access to stdout of process

@param [Hash] opts

Options

@option [Integer] wait_for_io

Wait for IO to be finished

@return [String]

The content of stdout
# File lib/aruba/processes/spawn_process.rb, line 205
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(*) click to toggle source

Stop command

# File lib/aruba/processes/spawn_process.rb, line 250
def stop(*)
  return @exit_status if stopped?

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

  terminate
end
terminate() click to toggle source

Terminate command

# File lib/aruba/processes/spawn_process.rb, line 264
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() click to toggle source

Wait for command to finish

# File lib/aruba/processes/spawn_process.rb, line 259
def wait
  @process.wait
end
write(input) click to toggle source
# File lib/aruba/processes/spawn_process.rb, line 233
def write(input)
  return if stopped?

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

  self
end

Private Instance Methods

command_path() click to toggle source
# File lib/aruba/processes/spawn_process.rb, line 344
def command_path
  @command_path ||=
    if Aruba.platform.builtin_shell_commands.include?(command)
      command
    else
      Aruba.platform.which(command, environment["PATH"])
    end
end
command_string() click to toggle source
# File lib/aruba/processes/spawn_process.rb, line 335
def command_string
  if command_path.nil?
    raise LaunchError,
          %(Command "#{command}" not found in PATH-variable "#{environment['PATH']}".)
  end

  Aruba.platform.command_string.new(command_path, *arguments)
end
read_temporary_output_file(file) click to toggle source
# File lib/aruba/processes/spawn_process.rb, line 358
def read_temporary_output_file(file)
  file.flush
  file.rewind
  data = file.read
  file.close

  data.force_encoding("UTF-8")
end
wait_for_io(time_to_wait) { || ... } click to toggle source
# File lib/aruba/processes/spawn_process.rb, line 353
def wait_for_io(time_to_wait)
  sleep time_to_wait
  yield
end