bin/god

   1 #!/usr/bin/env ruby
   2
   3 $:.unshift File.join(File.dirname(__FILE__), *%w[.. lib])
   4
   5 require 'rubygems'
   6 require 'optparse'
   7 require 'drb'
   8
   9 options = {:daemonize => true, :port => 17165}
  10
  11 opts = OptionParser.new do |opts|
  12   opts.banner = <<-EOF
  13 Usage:
  14   Starting:
  15     god -c <config file> [-p <port> | -b] [-P <file>] [-l <file>] [-D]
  16
  17   Querying:
  18     god <command> <argument> [-p <port>]
  19     god <command> [-p <port>]
  20     god -v
  21     god -V (must be run as root to be accurate on Linux)
  22
  23   Commands:
  24     start <task or group name>         start task or group
  25     restart <task or group name>       restart task or group
  26     stop <task or group name>          stop task or group
  27     monitor <task or group name>       monitor task or group
  28     unmonitor <task or group name>     unmonitor task or group
  29     load <file>                        load a config into a running god
  30     log <task name>                    show realtime log for given task
  31     status                             show status of each task
  32     quit                               stop god
  33     terminate                          stop god and all tasks
  34
  35   Options:
  36 EOF
  37
  38   opts.on("-cCONFIG", "--config-file CONFIG", "Configuration file") do |x|
  39     options[:config] = x
  40   end
  41
  42   opts.on("-pPORT", "--port PORT", "Communications port (default 17165)") do |x|
  43     options[:port] = x
  44   end
  45
  46   opts.on("-b", "--auto-bind", "Auto-bind to an unused port number") do
  47     options[:port] = "0"
  48   end
  49
  50   opts.on("-PFILE", "--pid FILE", "Where to write the PID file") do |x|
  51     options[:pid] = x
  52   end
  53
  54   opts.on("-lFILE", "--log FILE", "Where to write the log file") do |x|
  55     options[:log] = x
  56   end
  57
  58   opts.on("-D", "--no-daemonize", "Don't daemonize") do
  59     options[:daemonize] = false
  60   end
  61
  62   opts.on("-v", "--version", "Print the version number and exit") do
  63     options[:version] = true
  64   end
  65
  66   opts.on("-V", "Print extended version and build information") do
  67     options[:info] = true
  68   end
  69 end
  70
  71 opts.parse!
  72
  73 if options[:version]
  74   require 'god'
  75
  76   # print version
  77   puts "Version #{God::VERSION}"
  78   exit!(0)
  79 elsif options[:info]
  80   require 'god'
  81
  82   puts "Version: #{God::VERSION}"
  83   puts "Polls: enabled"
  84   puts "Events: " + God::EventHandler.event_system
  85
  86   exit!(0)
  87 elsif command = ARGV[0]
  88   require 'god'
  89
  90   # a command was specified
  91
  92   # connect to remote drb
  93   DRb.start_service
  94   server = DRbObject.new nil, "druby://127.0.0.1:#{options[:port]}"
  95
  96   begin
  97     server.ping
  98   rescue DRb::DRbConnError
  99     puts "The server is not available (or you do not have permissions to access it)"
 100     exit!
 101   rescue => e
 102     puts e.message
 103     puts e.backtrace.join("\n")
 104     exit!
 105   end
 106
 107   if command == 'load'
 108     file = ARGV[1]
 109
 110     puts "Sending '#{command}' command"
 111
 112     code = File.read(file)
 113
 114     watches = server.running_load(code)
 115
 116     # output response
 117     puts 'The following watches were affected:'
 118     watches.each do |w|
 119       puts '  ' + w.name
 120     end
 121   elsif command == 'status'
 122     begin
 123       watches = server.status
 124       watches.keys.sort.each do |name|
 125         state = watches[name][:state]
 126         puts "#{name}: #{state}"
 127       end
 128     rescue => e
 129       puts e.message
 130       puts e.backtrace.join("\n")
 131     end
 132   elsif command == 'log'
 133     begin
 134       Signal.trap('INT') { exit!(0) }
 135       name = ARGV[1]
 136       t = Time.at(0)
 137       loop do
 138         print server.running_log(name, t)
 139         t = Time.now
 140         sleep 1
 141       end
 142     rescue God::NoSuchWatchError
 143       puts "No such watch"
 144     rescue DRb::DRbConnError
 145       puts "The server went away"
 146     rescue => e
 147       puts e.message
 148       puts e.backtrace.join("\n")
 149     end
 150   elsif command == 'quit'
 151     begin
 152       server.terminate
 153       abort 'Could not stop god'
 154     rescue DRb::DRbConnError
 155       puts 'Stopped god'
 156     end
 157   elsif command == 'terminate'
 158     begin
 159       t = Thread.new { loop { STDOUT.print('.'); STDOUT.flush; sleep(1) } }
 160       if server.stop_all
 161         t.kill; STDOUT.puts
 162         puts 'Stopped all watches'
 163       else
 164         t.kill; STDOUT.puts
 165         puts 'Could not stop all watches within 10 seconds'
 166       end
 167     rescue => e
 168       puts e.message
 169       puts e.backtrace.join("\n")
 170     end
 171
 172     begin
 173       server.terminate
 174       abort 'Could not stop god'
 175     rescue DRb::DRbConnError
 176       puts 'Stopped god'
 177     end
 178   else
 179     # get the name of the watch/group
 180     name = ARGV[1]
 181
 182     begin
 183       puts "Sending '#{command}' command"
 184
 185       t = Thread.new { loop { sleep(1); STDOUT.print('.'); STDOUT.flush; sleep(1) } }
 186
 187       # send command
 188       watches = server.control(name, command)
 189
 190       # output response
 191       t.kill; STDOUT.puts
 192       puts 'The following watches were affected:'
 193       watches.each do |w|
 194         puts '  ' + w.name
 195       end
 196     rescue God::InvalidCommandError
 197       t.kill rescue nil; STDOUT.puts
 198       abort "Command '#{command}' is not valid. Run 'god --help' for usage"
 199     rescue => e
 200       puts e.message
 201       puts e.backtrace.join("\n")
 202     end
 203   end
 204
 205   exit!(0)
 206 elsif options[:config]
 207   # start god
 208   if !options[:daemonize]
 209     require 'god'
 210
 211     if options[:port]
 212       God.port = options[:port]
 213     end
 214
 215     begin
 216       load File.expand_path(options[:config])
 217     rescue => e
 218       puts e.message
 219       puts e.backtrace.join("\n")
 220       abort "There was an error in your configuration file (see above)"
 221     end
 222   else
 223     # trap and ignore SIGHUP
 224     Signal.trap('HUP') {}
 225
 226     pid = fork do
 227       begin
 228         require 'god'
 229
 230         log_file = options[:log] || "/dev/null"
 231
 232         unless God::EventHandler.loaded?
 233           puts
 234           puts "***********************************************************************"
 235           puts "*"
 236           puts "* Event conditions are not available for your installation of god."
 237           puts "* You may still use and write custom conditions using the poll system"
 238           puts "*"
 239           puts "***********************************************************************"
 240           puts
 241         end
 242
 243         # set port if requested
 244         if options[:port]
 245           God.port = options[:port]
 246         end
 247
 248         # load config
 249         begin
 250           load File.expand_path(options[:config])
 251         rescue => e
 252           puts e.message
 253           puts e.backtrace.join("\n")
 254           abort "There was an error in your configuration file (see above)"
 255         end
 256
 257         # reset file descriptors
 258         STDIN.reopen "/dev/null"
 259         STDOUT.reopen(log_file, "a")
 260         STDERR.reopen STDOUT
 261       rescue => e
 262         puts e.message
 263         puts e.backtrace.join("\n")
 264         abort "There was a fatal system error while starting god (see above)"
 265       end
 266     end
 267
 268     if options[:pid]
 269       File.open(options[:pid], 'w') { |f| f.write pid }
 270     end
 271
 272     ::Process.detach pid
 273
 274     exit!(0)
 275   end
 276 else
 277   puts opts.help
 278 end