lib/god/cli/command.rb

   1 module God
   2   module CLI
   3
   4     class Command
   5       def initialize(command, options, args)
   6         @command = command
   7         @options = options
   8         @args = args
   9
  10         dispatch
  11       end
  12
  13       def setup
  14         # connect to drb unix socket
  15         DRb.start_service
  16         @server = DRbObject.new(nil, God::Socket.socket(@options[:port]))
  17
  18         # ping server to ensure that it is responsive
  19         begin
  20           @server.ping
  21         rescue DRb::DRbConnError
  22           puts "The server is not available (or you do not have permissions to access it)"
  23           abort
  24         end
  25       end
  26
  27       def dispatch
  28         if %w{load status log quit terminate}.include?(@command)
  29           setup
  30           send("#{@command}_command")
  31         elsif %w{start stop restart monitor unmonitor remove}.include?(@command)
  32           setup
  33           lifecycle_command
  34         elsif @command == 'check'
  35           check_command
  36         else
  37           puts "Command '#{@command}' is not valid. Run 'god --help' for usage"
  38           abort
  39         end
  40       end
  41
  42       def load_command
  43         file = @args[1]
  44
  45         puts "Sending '#{@command}' command"
  46         puts
  47
  48         unless File.exist?(file)
  49           abort "File not found: #{file}"
  50         end
  51
  52         names, errors = *@server.running_load(File.read(file), File.expand_path(file))
  53
  54         # output response
  55         unless names.empty?
  56           puts 'The following tasks were affected:'
  57           names.each do |w|
  58             puts '  ' + w
  59           end
  60         end
  61
  62         unless errors.empty?
  63           puts errors
  64           exit(1)
  65         end
  66       end
  67
  68       def status_command
  69         watches = @server.status
  70         watches.keys.sort.each do |name|
  71           state = watches[name][:state]
  72           puts "#{name}: #{state}"
  73         end
  74       end
  75
  76       def log_command
  77         begin
  78           Signal.trap('INT') { exit }
  79           name = @args[1]
  80
  81           unless name
  82             puts "You must specify a Task or Group name"
  83             exit!
  84           end
  85
  86           t = Time.at(0)
  87           loop do
  88             print @server.running_log(name, t)
  89             t = Time.now
  90             sleep 1
  91           end
  92         rescue God::NoSuchWatchError
  93           puts "No such watch"
  94         rescue DRb::DRbConnError
  95           puts "The server went away"
  96         end
  97       end
  98
  99       def quit_command
 100         begin
 101           @server.terminate
 102           abort 'Could not stop god'
 103         rescue DRb::DRbConnError
 104           puts 'Stopped god'
 105         end
 106       end
 107
 108       def terminate_command
 109         t = Thread.new { loop { STDOUT.print('.'); STDOUT.flush; sleep(1) } }
 110         if @server.stop_all
 111           t.kill; STDOUT.puts
 112           puts 'Stopped all watches'
 113         else
 114           t.kill; STDOUT.puts
 115           puts 'Could not stop all watches within 10 seconds'
 116         end
 117
 118         begin
 119           @server.terminate
 120           abort 'Could not stop god'
 121         rescue DRb::DRbConnError
 122           puts 'Stopped god'
 123         end
 124       end
 125
 126       def check_command
 127         Thread.new do
 128           begin
 129             event_system = God::EventHandler.event_system
 130             puts "using event system: #{event_system}"
 131
 132             if God::EventHandler.loaded?
 133               puts "starting event handler"
 134               God::EventHandler.start
 135             else
 136               puts "[fail] event system did not load"
 137               exit(1)
 138             end
 139
 140             puts 'forking off new process'
 141
 142             pid = fork do
 143               loop { sleep(1) }
 144             end
 145
 146             puts "forked process with pid = #{pid}"
 147
 148             God::EventHandler.register(pid, :proc_exit) do
 149               puts "[ok] process exit event received"
 150               exit(0)
 151             end
 152
 153             sleep(1)
 154
 155             puts "killing process"
 156
 157             ::Process.kill('KILL', pid)
 158           rescue => e
 159             puts e.message
 160             puts e.backtrace.join("\n")
 161           end
 162         end
 163
 164         sleep(2)
 165
 166         puts "[fail] never received process exit event"
 167         exit(1)
 168       end
 169
 170       def lifecycle_command
 171         # get the name of the watch/group
 172         name = @args[1]
 173
 174         puts "Sending '#{@command}' command"
 175
 176         t = Thread.new { loop { sleep(1); STDOUT.print('.'); STDOUT.flush; sleep(1) } }
 177
 178         # send @command
 179         watches = @server.control(name, @command)
 180
 181         # output response
 182         t.kill; STDOUT.puts
 183         unless watches.empty?
 184           puts 'The following watches were affected:'
 185           watches.each do |w|
 186             puts '  ' + w
 187           end
 188         else
 189           puts 'No matching task or group'
 190         end
 191       end
 192     end # Command
 193
 194   end
 195 end