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           t = Time.at(0)
  81           loop do
  82             print @server.running_log(name, t)
  83             t = Time.now
  84             sleep 1
  85           end
  86         rescue God::NoSuchWatchError
  87           puts "No such watch"
  88         rescue DRb::DRbConnError
  89           puts "The server went away"
  90         end
  91       end
  92
  93       def quit_command
  94         begin
  95           @server.terminate
  96           abort 'Could not stop god'
  97         rescue DRb::DRbConnError
  98           puts 'Stopped god'
  99         end
 100       end
 101
 102       def terminate_command
 103         t = Thread.new { loop { STDOUT.print('.'); STDOUT.flush; sleep(1) } }
 104         if @server.stop_all
 105           t.kill; STDOUT.puts
 106           puts 'Stopped all watches'
 107         else
 108           t.kill; STDOUT.puts
 109           puts 'Could not stop all watches within 10 seconds'
 110         end
 111
 112         begin
 113           @server.terminate
 114           abort 'Could not stop god'
 115         rescue DRb::DRbConnError
 116           puts 'Stopped god'
 117         end
 118       end
 119
 120       def check_command
 121         Thread.new do
 122           begin
 123             event_system = God::EventHandler.event_system
 124             puts "using event system: #{event_system}"
 125
 126             if God::EventHandler.loaded?
 127               puts "starting event handler"
 128               God::EventHandler.start
 129             else
 130               puts "[fail] event system did not load"
 131               exit(1)
 132             end
 133
 134             puts 'forking off new process'
 135
 136             pid = fork do
 137               loop { sleep(1) }
 138             end
 139
 140             puts "forked process with pid = #{pid}"
 141
 142             God::EventHandler.register(pid, :proc_exit) do
 143               puts "[ok] process exit event received"
 144               exit(0)
 145             end
 146
 147             sleep(1)
 148
 149             puts "killing process"
 150
 151             ::Process.kill('KILL', pid)
 152           rescue => e
 153             puts e.message
 154             puts e.backtrace.join("\n")
 155           end
 156         end
 157
 158         sleep(2)
 159
 160         puts "[fail] never received process exit event"
 161         exit(1)
 162       end
 163
 164       def lifecycle_command
 165         # get the name of the watch/group
 166         name = @args[1]
 167
 168         puts "Sending '#{@command}' command"
 169
 170         t = Thread.new { loop { sleep(1); STDOUT.print('.'); STDOUT.flush; sleep(1) } }
 171
 172         # send @command
 173         watches = @server.control(name, @command)
 174
 175         # output response
 176         t.kill; STDOUT.puts
 177         unless watches.empty?
 178           puts 'The following watches were affected:'
 179           watches.each do |w|
 180             puts '  ' + w
 181           end
 182         else
 183           puts 'No matching task or group'
 184         end
 185       end
 186     end # Command
 187
 188   end
 189 end