Class: Puppet::Application

Inherits:
Object show all
Extended by:
Util
Includes:
Util
Defined in:
lib/puppet/application.rb

Overview

This class handles all the aspects of a Puppet application/executable

  • setting up options

  • setting up logs

  • choosing what to run

  • representing execution status

Usage

An application is a subclass of Puppet::Application.

For legacy compatibility,

Puppet::Application[:example].run

is equivalent to

Puppet::Application::Example.new.run

class Puppet::Application::Example < Puppet::Application

def preinit
    # perform some pre initialization
    @all = false
end

# run_command is called to actually run the specified command
def run_command
    send Puppet::Util::CommandLine.new.args.shift
end

# option uses metaprogramming to create a method
# and also tells the option parser how to invoke that method
option("--arg ARGUMENT") do |v|
    @args << v
end

option("--debug", "-d") do |v|
    @debug = v
end

option("--all", "-a:) do |v|
    @all = v
end

def handle_unknown(opt,arg)
    # last chance to manage an option
    ...
    # let's say to the framework we finally handle this option
    true
end

def read
    # read action
end

def write
    # writeaction
end

end

Preinit

The preinit block is the first code to be called in your application, before option parsing, setup or command execution.

Options

Puppet::Application uses OptionParser to manage the application options. Options are defined with the option method to which are passed various arguments, including the long option, the short option, a description… Refer to OptionParser documentation for the exact format.

  • If the option method is given a block, this one will be called whenever

the option is encountered in the command-line argument.

  • If the option method has no block, a default functionality will be used, that

stores the argument (or true/false if the option doesn't require an argument) in the global (to the application) options array.

  • If a given option was not defined by a the option method, but it exists as a Puppet settings:

  • if unknown was used with a block, it will be called with the option name and argument

  • if unknown wasn't used, then the option/argument is handed to Puppet.settings.handlearg for a default behavior

–help is managed directly by the Puppet::Application class, but can be overridden.

Setup

Applications can use the setup block to perform any initialization. The default setup behaviour is to: read Puppet configuration and manage log level and destination

What and how to run

If the dispatch block is defined it is called. This block should return the name of the registered command to be run. If it doesn't exist, it defaults to execute the main command if defined.

Execution state

The class attributes/methods of Puppet::Application serve as a global place to set and query the execution status of the application: stopping, restarting, etc. The setting of the application status does not directly affect its running status; it's assumed that the various components within the application will consult these settings appropriately and affect their own processing accordingly. Control operations (signal handlers and the like) should set the status appropriately to indicate to the overall system that it's the process of stopping or restarting (or just running as usual).

So, if something in your application needs to stop the process, for some reason, you might consider:

def stop_me!
    # indicate that we're stopping
    Puppet::Application.stop!
    # ...do stuff...
end

And, if you have some component that involves a long-running process, you might want to consider:

def my_long_process(giant_list_to_munge)
    giant_list_to_munge.collect do |member|
        # bail if we're stopping
        return if Puppet::Application.stop_requested?
        process_member(member)
    end
end

Defined Under Namespace

Classes: Agent, Apply, Catalog, Cert, CommandLineArgs, Config, Describe, Device, Doc, Epp, FaceBase, Facts, Filebucket, Generate, Help, IndirectionBase, Key, Lookup, Man, Module, Node, Parser, Plugin, Report, Resource, Script, Ssl, Status

Constant Summary collapse

DOCPATTERN = 
::File.expand_path(::File.dirname(__FILE__) + "/util/command_line/*" )

Constants included from Util

Util::AbsolutePathPosix, Util::AbsolutePathWindows, Util::DEFAULT_POSIX_MODE, Util::DEFAULT_WINDOWS_MODE, Util::RFC_3986_URI_REGEX

Constants included from Util::SymbolicFileMode

Util::SymbolicFileMode::SetGIDBit, Util::SymbolicFileMode::SetUIDBit, Util::SymbolicFileMode::StickyBit, Util::SymbolicFileMode::SymbolicMode, Util::SymbolicFileMode::SymbolicSpecialToBit

Constants included from Util::POSIX

Util::POSIX::LOCALE_ENV_VARS, Util::POSIX::USER_ENV_VARS

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Util

absolute_path?, benchmark, chuser, clear_environment, default_env, deterministic_rand, deterministic_rand_int, exit_on_fail, get_env, get_environment, logmethods, merge_environment, path_to_uri, pretty_backtrace, replace_file, safe_posix_fork, set_env, symbolizehash, thinmark, uri_encode, uri_query_encode, uri_to_path, which, withenv, withumask

Methods included from Util::SymbolicFileMode

#normalize_symbolic_mode, #symbolic_mode_to_int, #valid_symbolic_mode?

Methods included from Util::POSIX

#get_posix_field, #gid, groups_of, #idfield, #methodbyid, #methodbyname, #search_posix_field, #uid

Constructor Details

#initialize(command_line = Puppet::Util::CommandLine.new) ⇒ Application 


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# File 'lib/puppet/application.rb', line 344

def initialize(command_line = Puppet::Util::CommandLine.new)
  @command_line = CommandLineArgs.new(command_line.subcommand_name, command_line.args.dup)
  @options = {}
end

Class Attribute Details

.run_status ⇒ Object

Returns the value of attribute run_status


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# File 'lib/puppet/application.rb', line 134

def run_status
  @run_status
end

Instance Attribute Details

#command_line ⇒ Object (readonly)

Returns the value of attribute command_line


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# File 'lib/puppet/application.rb', line 314

def command_line
  @command_line
end

#options ⇒ Object (readonly)

Returns the value of attribute options


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# File 'lib/puppet/application.rb', line 314

def options
  @options
end

Class Method Details

.[](name) ⇒ Object 


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# File 'lib/puppet/application.rb', line 273

def [](name)
  find(name).new
end

.available_application_names ⇒ Array<String>

Returns the names of available applications


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# File 'lib/puppet/application.rb', line 211

def available_application_names
  # Use our configured environment to load the application, as it may
  # be in a module we installed locally, otherwise fallback to our
  # current environment (*root*). Once we load the application the
  # current environment will change from *root* to the application
  # specific environment.
  environment = Puppet.lookup(:environments).get(Puppet[:environment]) ||
                Puppet.lookup(:current_environment)
  @loader.files_to_load(environment).map do |fn|
    ::File.basename(fn, '.rb')
  end.uniq
end


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# File 'lib/puppet/application.rb', line 198

def banner(banner = nil)
  @banner ||= banner
end

.clear! ⇒ Object 


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# File 'lib/puppet/application.rb', line 136

def clear!
  self.run_status = nil
end

.clear? ⇒ Boolean

Indicates that Puppet::Application believes that it's in usual running run_mode (no stop/restart request currently active).


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# File 'lib/puppet/application.rb', line 168

def clear?
  run_status.nil?
end

.clear_everything_for_tests ⇒ Object

This is for testing only


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# File 'lib/puppet/application.rb', line 309

def clear_everything_for_tests
  @run_mode = @banner = @run_status = @option_parser_commands = nil
end

.controlled_run(&block) ⇒ Object

Only executes the given block if the run status of Puppet::Application is clear (no restarts, stops, etc. requested). Upon block execution, checks the run status again; if a restart has been requested during the block's execution, then controlled_run will send a new HUP signal to the current process. Thus, long-running background processes can potentially finish their work before a restart.


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# File 'lib/puppet/application.rb', line 177

def controlled_run(&block)
  return unless clear?
  result = block.call
  Process.kill(:HUP, $PID) if restart_requested?
  result
end

.environment_mode(mode_name) ⇒ Object

Sets environment_mode name

Raises:


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# File 'lib/puppet/application.rb', line 297

def environment_mode(mode_name)
  raise Puppet::Error, _("Invalid environment mode '%{mode_name}'") % { mode_name: mode_name } unless [:local, :remote, :not_required].include?(mode_name)
  @environment_mode = mode_name
end

.exit(code) ⇒ Object

this is used for testing


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# File 'lib/puppet/application.rb', line 495

def self.exit(code)
  exit(code)
end

.find(application_name) ⇒ Class

Finds the class for a given application and loads the class. This does not create an instance of the application, it only gets a handle to the class. The code for the application is expected to live in a ruby file `puppet/application/##name.rb` that is available on the `$LOAD_PATH`.

Raises:

  • (Puppet::Error) —

    if the application class was not found.

  • (LoadError) —

    if there was a problem loading the application file.


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# File 'lib/puppet/application.rb', line 234

def find(application_name)
  begin
    require @loader.expand(application_name.to_s.downcase)
  rescue LoadError => e
    Puppet.log_and_raise(e, _("Unable to find application '%{application_name}'. %{error}") % { application_name: application_name, error: e })
  end

  class_name = Puppet::Util::ConstantInflector.file2constant(application_name.to_s)

  clazz = try_load_class(class_name)

  ################################################################
  #### Begin 2.7.x backward compatibility hack;
  ####  eventually we need to issue a deprecation warning here,
  ####  and then get rid of this stanza in a subsequent release.
  ################################################################
  if (clazz.nil?)
    class_name = application_name.capitalize
    clazz = try_load_class(class_name)
  end
  ################################################################
  #### End 2.7.x backward compatibility hack
  ################################################################

  if clazz.nil?
    raise Puppet::Error.new(_("Unable to load application class '%{class_name}' from file 'puppet/application/%{application_name}.rb'") % { class_name: class_name, application_name: application_name })
  end

  return clazz
end

.get_environment_mode ⇒ Object

Gets environment_mode name. If none is set with `environment_mode=`, default to :local.


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# File 'lib/puppet/application.rb', line 304

def get_environment_mode
  @environment_mode || :local
end

.interrupted? ⇒ Boolean

Indicates that one of stop! or start! was invoked on Puppet::Application, and some kind of process shutdown/short-circuit may be necessary.


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# File 'lib/puppet/application.rb', line 162

def interrupted?
  [:restart_requested, :stop_requested].include? run_status
end

.option(*options, &block) ⇒ Object

used to declare code that handle an option


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# File 'lib/puppet/application.rb', line 185

def option(*options, &block)
  long = options.find { |opt| opt =~ /^--/ }.gsub(/^--(?:\[no-\])?([^ =]+).*$/, '\1' ).tr('-','_')
  fname = "handle_#{long}".intern
  if (block_given?)
    define_method(fname, &block)
  else
    define_method(fname) do |value|
      self.options["#{long}".to_sym] = value
    end
  end
  self.option_parser_commands << [options, fname]
end

.option_parser_commands ⇒ Object 


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# File 'lib/puppet/application.rb', line 202

def option_parser_commands
  @option_parser_commands ||= (
    superclass.respond_to?(:option_parser_commands) ? superclass.option_parser_commands.dup : []
  )
  @option_parser_commands
end

.restart! ⇒ Object 


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# File 'lib/puppet/application.rb', line 144

def restart!
  self.run_status = :restart_requested
end

.restart_requested? ⇒ Boolean

Indicates that Puppet::Application.restart! has been invoked and components should do what is necessary to facilitate a restart.


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# File 'lib/puppet/application.rb', line 150

def restart_requested?
  :restart_requested == run_status
end

.run_mode(mode_name = nil) ⇒ Object

Sets or gets the run_mode name. Sets the run_mode name if a mode_name is passed. Otherwise, gets the run_mode or a default run_mode


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# File 'lib/puppet/application.rb', line 280

def run_mode( mode_name = nil)
  if mode_name
    Puppet.settings.preferred_run_mode = mode_name
  end

  return @run_mode if @run_mode and not mode_name

  require 'puppet/util/run_mode'
  @run_mode = Puppet::Util::RunMode[ mode_name || Puppet.settings.preferred_run_mode ]
end

.stop! ⇒ Object 


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# File 'lib/puppet/application.rb', line 140

def stop!
  self.run_status = :stop_requested
end

.stop_requested? ⇒ Boolean

Indicates that Puppet::Application.stop! has been invoked and components should do what is necessary for a clean stop.


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# File 'lib/puppet/application.rb', line 156

def stop_requested?
  :stop_requested == run_status
end

.try_load_class(class_name) ⇒ Class

Given the fully qualified name of a class, attempt to get the class instance.


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# File 'lib/puppet/application.rb', line 268

def try_load_class(class_name)
    return self.const_defined?(class_name) ? const_get(class_name) : nil
end

Instance Method Details

#app_defaults ⇒ Object 


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# File 'lib/puppet/application.rb', line 330

def app_defaults()
  Puppet::Settings.app_defaults_for_run_mode(self.class.run_mode).merge(
      :name => name
  )
end

#configure_indirector_routes ⇒ Object 


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# File 'lib/puppet/application.rb', line 432

def configure_indirector_routes
  Puppet::ApplicationSupport.configure_indirector_routes(name.to_s)
end

#deprecate ⇒ Object

call in setup of subclass to deprecate an application


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# File 'lib/puppet/application.rb', line 350

def deprecate
  @deprecated = true
end

#deprecated? ⇒ Boolean 


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# File 'lib/puppet/application.rb', line 354

def deprecated?
  @deprecated
end

#handle_logdest_arg(arg) ⇒ Object 


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# File 'lib/puppet/application.rb', line 420

def handle_logdest_arg(arg)
  return if arg.nil?

  begin
    Puppet[:logdest] = arg
    Puppet::Util::Log.newdestination(arg)
    options[:setdest] = true
  rescue => detail
    Puppet.log_and_raise(detail, _("Could not set logdest to %{dest}.") % { dest: arg })
  end
end

#handlearg(opt, val) ⇒ Object 


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# File 'lib/puppet/application.rb', line 489

def handlearg(opt, val)
  opt, val = Puppet::Settings.clean_opt(opt, val)
  send(:handle_unknown, opt, val) if respond_to?(:handle_unknown)
end

#help ⇒ Object 


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# File 'lib/puppet/application.rb', line 503

def help
  _("No help available for puppet %{app_name}") % { app_name: name }
end

#initialize_app_defaults ⇒ Object 


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# File 'lib/puppet/application.rb', line 336

def initialize_app_defaults()
  Puppet.settings.initialize_app_defaults(app_defaults)
end

#log_runtime_environment(extra_info = nil) ⇒ void

This method returns an undefined value.

Output basic information about the runtime environment for debugging purposes.


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# File 'lib/puppet/application.rb', line 444

def log_runtime_environment(extra_info=nil)
  runtime_info = {
    'puppet_version' => Puppet.version,
    'ruby_version'   => RUBY_VERSION,
    'run_mode'       => self.class.run_mode.name,
  }
  runtime_info['default_encoding'] = Encoding.default_external
  runtime_info.merge!(extra_info) unless extra_info.nil?

  Puppet.debug 'Runtime environment: ' + runtime_info.map{|k,v| k + '=' + v.to_s}.join(', ')
end

#main ⇒ Object

Raises:

  • (NotImplementedError) 

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# File 'lib/puppet/application.rb', line 385

def main
  raise NotImplementedError, _("No valid command or main")
end

#name ⇒ Object 


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# File 'lib/puppet/application.rb', line 499

def name
  self.class.to_s.sub(/.*::/,"").downcase.to_sym
end

#parse_options ⇒ Object 


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# File 'lib/puppet/application.rb', line 456

def parse_options
  # Create an option parser
  option_parser = OptionParser.new(self.class.banner)

  # Here we're building up all of the options that the application may need to handle.  The main
  # puppet settings defined in "defaults.rb" have already been parsed once (in command_line.rb) by
  # the time we get here; however, our app may wish to handle some of them specially, so we need to
  # make the parser aware of them again.  We might be able to make this a bit more efficient by
  # re-using the parser object that gets built up in command_line.rb.  --cprice 2012-03-16

  # Add all global options to it.
  Puppet.settings.optparse_addargs([]).each do |option|
    option_parser.on(*option) do |arg|
      handlearg(option[0], arg)
    end
  end

  # Add options that are local to this application, which were
  # created using the "option()" metaprogramming method.  If there
  # are any conflicts, this application's options will be favored.
  self.class.option_parser_commands.each do |options, fname|
    option_parser.on(*options) do |value|
      # Call the method that "option()" created.
      self.send(fname, value)
    end
  end

  # Scan command line.  We just hand any exceptions to our upper levels,
  # rather than printing help and exiting, so that we can meaningfully
  # respond with context-sensitive help if we want to. --daniel 2011-04-12
  option_parser.parse!(self.command_line.args)
end

#preinit ⇒ Object

override to execute code before running anything else


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# File 'lib/puppet/application.rb', line 341

def preinit
end

#run ⇒ void

This method returns an undefined value.

Execute the application.


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# File 'lib/puppet/application.rb', line 361

def run

  # I don't really like the names of these lifecycle phases.  It would be nice to change them to some more meaningful
  # names, and make deprecated aliases.  --cprice 2012-03-16

  exit_on_fail(_("Could not get application-specific default settings")) do
    initialize_app_defaults
  end

  Puppet::ApplicationSupport.push_application_context(self.class.run_mode, self.class.get_environment_mode)

  exit_on_fail(_("Could not initialize"))                { preinit }
  exit_on_fail(_("Could not parse application options")) { parse_options }
  exit_on_fail(_("Could not prepare for execution"))     { setup }

  if deprecated?
    Puppet.deprecation_warning(_("`puppet %{name}` is deprecated and will be removed in a future release.") % { name: name })
  end

  exit_on_fail(_("Could not configure routes from %{route_file}") % { route_file: Puppet[:route_file] }) { configure_indirector_routes }
  exit_on_fail(_("Could not log runtime debug info"))                       { log_runtime_environment }
  exit_on_fail(_("Could not run"))                                          { run_command }
end

#run_command ⇒ Object 


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# File 'lib/puppet/application.rb', line 389

def run_command
  main
end

#set_log_level(opts = nil) ⇒ Object 


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# File 'lib/puppet/application.rb', line 411

def set_log_level(opts = nil)
  opts ||= options
  if opts[:debug]
    Puppet::Util::Log.level = :debug
  elsif opts[:verbose] && !Puppet::Util::Log.sendlevel?(:info)
    Puppet::Util::Log.level = :info
  end
end

#setup ⇒ Object 


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# File 'lib/puppet/application.rb', line 393

def setup
  setup_logs
end

#setup_logs ⇒ Object 


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# File 'lib/puppet/application.rb', line 397

def setup_logs
  handle_logdest_arg(Puppet[:logdest]) if !options[:setdest]

  unless options[:setdest]
    if options[:debug] || options[:verbose]
      Puppet::Util::Log.newdestination(:console)
    end
  end

  set_log_level

  Puppet::Util::Log.setup_default unless options[:setdest]
end

#summary ⇒ Object

The description used in top level `puppet help` output If left empty in implementations, we will attempt to extract the summary from the help text itself.


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# File 'lib/puppet/application.rb', line 510

def summary
  ""
end