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