Class: God::Process

200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281

# File 'lib/god/process.rb', line 200

def call_action(action)
  command = send(action)
  
  if action == :stop && command.nil?
    pid = self.pid
    name = self.name
    command = lambda do
      applog(self, :info, "#{self.name} stop: default lambda killer")
      
      ::Process.kill(@stop_signal, pid) rescue nil
      applog(self, :info, "#{self.name} sent SIG#{@stop_signal}")
      
      # Poll to see if it's dead
      @stop_timeout.times do
        begin
          ::Process.kill(0, pid)
        rescue Errno::ESRCH
          # It died. Good.
          applog(self, :info, "#{self.name} process stopped")
          return
        end
        
        sleep 1
      end
      
      ::Process.kill('KILL', pid) rescue nil
      applog(self, :warn, "#{self.name} still alive after #{@stop_timeout}s; sent SIGKILL")
    end
  end
        
  if command.kind_of?(String)
    pid = nil
    
    if [:start, :restart].include?(action) && @tracking_pid
      # double fork god-daemonized processes
      # we don't want to wait for them to finish
      r, w = IO.pipe
      begin
        opid = fork do
          STDOUT.reopen(w)
          r.close
          pid = self.spawn(command)
          puts pid.to_s # send pid back to forker
        end
        
        ::Process.waitpid(opid, 0)
        w.close
        pid = r.gets.chomp
      ensure
        # make sure the file descriptors get closed no matter what
        r.close rescue nil
        w.close rescue nil
      end
    else
      # single fork self-daemonizing processes
      # we want to wait for them to finish
      pid = self.spawn(command)
      status = ::Process.waitpid2(pid, 0)
      exit_code = status[1] >> 8
      
      if exit_code != 0
        applog(self, :warn, "#{self.name} #{action} command exited with non-zero code = #{exit_code}")
      end
      
      ensure_stop if action == :stop
    end
    
    if @tracking_pid or (@pid_file.nil? and WRITES_PID.include?(action))
      File.open(default_pid_file, 'w') do |f|
        f.write pid
      end
      
      @tracking_pid = true
      @pid_file = default_pid_file
    end
  elsif command.kind_of?(Proc)
    # lambda command
    command.call
  else
    raise NotImplementedError
  end
end

196
197
198

# File 'lib/god/process.rb', line 196

def default_pid_file
  File.join(God.pid_file_directory, "#{self.name}.pid")
end

332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355

# File 'lib/god/process.rb', line 332

def ensure_stop
  applog(self, :warn, "#{self.name} ensuring stop...")

  unless self.pid
    applog(self, :warn, "#{self.name} stop called but pid is uknown")
    return
  end
  
  # Poll to see if it's dead
  @stop_timeout.times do
    begin
      ::Process.kill(0, self.pid)
    rescue Errno::ESRCH
      # It died. Good.
      return
    end
    
    sleep 1
  end
  
  # last resort
  ::Process.kill('KILL', self.pid) rescue nil
  applog(self, :warn, "#{self.name} still alive after #{@stop_timeout}s; sent SIGKILL")
end

30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49

# File 'lib/god/process.rb', line 30

def file_writable?(file)
  pid = fork do
    begin
      uid_num = Etc.getpwnam(self.uid).uid if self.uid
      gid_num = Etc.getgrnam(self.gid).gid if self.gid

      ::Dir.chroot(self.chroot) if self.chroot
      ::Process.groups = [gid_num] if self.gid
      ::Process::Sys.setgid(gid_num) if self.gid
      ::Process::Sys.setuid(uid_num) if self.uid
    rescue ArgumentError, Errno::EPERM, Errno::ENOENT
      exit(1)
    end

    File.writable?(file_in_chroot(file)) ? exit(0) : exit(1)
  end
  
  wpid, status = ::Process.waitpid2(pid)
  status.exitstatus == 0 ? true : false
end

163
164
165
166
167
168
169
170
171
172
173

# File 'lib/god/process.rb', line 163

def pid
  contents = File.read(self.pid_file).strip rescue ''
  real_pid = contents =~ /^\d+$/ ? contents.to_i : nil
  
  if real_pid
    @pid = real_pid
    real_pid
  else
    @pid
  end
end

154
155
156

# File 'lib/god/process.rb', line 154

def pid_file
  @pid_file ||= default_pid_file
end

143
144
145
146
147
148
149
150
151
152

# File 'lib/god/process.rb', line 143

def pid_file=(value)
  # if value is nil, do the right thing
  if value
    @tracking_pid = false
  else
    @tracking_pid = true
  end
  
  @pid_file = value
end

192
193
194

# File 'lib/god/process.rb', line 192

def restart!
  call_action(:restart)
end

178
179
180
181
182

# File 'lib/god/process.rb', line 178

def signal(sig)
  sig = sig.to_i if sig.to_i != 0
  applog(self, :info, "#{self.name} sending signal '#{sig}' to pid #{self.pid}")
  ::Process.kill(sig, self.pid) rescue nil
end

287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326

# File 'lib/god/process.rb', line 287

def spawn(command)
  fork do
    File.umask self.umask if self.umask
    uid_num = Etc.getpwnam(self.uid).uid if self.uid
    gid_num = Etc.getgrnam(self.gid).gid if self.gid

    ::Dir.chroot(self.chroot) if self.chroot
    ::Process.setsid
    ::Process.groups = [gid_num] if self.gid
    ::Process::Sys.setgid(gid_num) if self.gid
    ::Process::Sys.setuid(uid_num) if self.uid
    self.dir ||= '/'
    Dir.chdir self.dir
    $0 = command
    STDIN.reopen "/dev/null"
    if self.log_cmd
      STDOUT.reopen IO.popen(self.log_cmd, "a") 
    else
      STDOUT.reopen file_in_chroot(self.log), "a"        
    end
    if err_log_cmd
      STDERR.reopen IO.popen(err_log_cmd, "a") 
    elsif err_log && (log_cmd || err_log != log)
      STDERR.reopen file_in_chroot(err_log), "a"        
    else
      STDERR.reopen STDOUT
    end
    
    # close any other file descriptors
    3.upto(256){|fd| IO::new(fd).close rescue nil}

    if self.env && self.env.is_a?(Hash)
      self.env.each do |(key, value)|
        ENV[key] = value.to_s
      end
    end

    exec command unless command.empty?
  end
end

184
185
186

# File 'lib/god/process.rb', line 184

def start!
  call_action(:start)
end

188
189
190

# File 'lib/god/process.rb', line 188

def stop!
  call_action(:stop)
end

51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139

# File 'lib/god/process.rb', line 51

def valid?
  # determine if we're tracking pid or not
  self.pid_file
  
  valid = true
  
  # a start command must be specified
  if self.start.nil?
    valid = false
    applog(self, :error, "No start command was specified")
  end
  
  # uid must exist if specified
  if self.uid
    begin
      Etc.getpwnam(self.uid)
    rescue ArgumentError
      valid = false
      applog(self, :error, "UID for '#{self.uid}' does not exist")
    end
  end
  
  # gid must exist if specified
  if self.gid
    begin
      Etc.getgrnam(self.gid)
    rescue ArgumentError
      valid = false
      applog(self, :error, "GID for '#{self.gid}' does not exist")
    end
  end
  
  # dir must exist and be a directory if specified
  if self.dir
    if !File.exist?(self.dir)
      valid = false
      applog(self, :error, "Specified directory '#{self.dir}' does not exist")
    elsif !File.directory?(self.dir)
      valid = false
      applog(self, :error, "Specified directory '#{self.dir}' is not a directory")
    end
  end
  
  # pid dir must exist if specified
  if !@tracking_pid && !File.exist?(File.dirname(self.pid_file))
    valid = false
    applog(self, :error, "PID file directory '#{File.dirname(self.pid_file)}' does not exist")
  end
  
  # pid dir must be writable if specified
  if !@tracking_pid && File.exist?(File.dirname(self.pid_file)) && !file_writable?(File.dirname(self.pid_file))
    valid = false
    applog(self, :error, "PID file directory '#{File.dirname(self.pid_file)}' is not writable by #{self.uid || Etc.getlogin}")
  end
  
  # log dir must exist
  if !File.exist?(File.dirname(self.log))
    valid = false
    applog(self, :error, "Log directory '#{File.dirname(self.log)}' does not exist")
  end
  
  # log file or dir must be writable
  if File.exist?(self.log)
    unless file_writable?(self.log)
      valid = false
      applog(self, :error, "Log file '#{self.log}' exists but is not writable by #{self.uid || Etc.getlogin}")
    end
  else
    unless file_writable?(File.dirname(self.log))
      valid = false
      applog(self, :error, "Log directory '#{File.dirname(self.log)}' is not writable by #{self.uid || Etc.getlogin}")
    end
  end

  # chroot directory must exist and have /dev/null in it
  if self.chroot
    if !File.directory?(self.chroot)
      valid = false
      applog(self, :error, "CHROOT directory '#{self.chroot}' does not exist")
    end

    if !File.exist?(File.join(self.chroot, '/dev/null'))
      valid = false
      applog(self, :error, "CHROOT directory '#{self.chroot}' does not contain '/dev/null'")
    end
  end
  
  valid
end