6 # Implements a simple DSL for configuring a unicorn server.
8 # Example (when used with the unicorn config file):
10 # listen '/tmp/my_app.sock', :backlog => 1
11 # listen '0.0.0.0:9292'
13 # pid "/tmp/my_app.pid"
14 # after_fork do |server,worker|
15 # server.listen("127.0.0.1:#{9293 + worker.nr}") rescue nil
18 # The default logger writes its output to $stderr
19 DEFAULT_LOGGER = Logger.new($stderr) unless defined?(DEFAULT_LOGGER)
21 # Default settings for Unicorn
25 :logger => DEFAULT_LOGGER,
26 :worker_processes => 1,
27 :after_fork => lambda { |server, worker|
28 server.logger.info("worker=#{worker.nr} spawned pid=#{$$}")
30 # per-process listener ports for debugging/admin:
31 # "rescue nil" statement is needed because USR2 will
32 # cause the master process to reexecute itself and the
33 # per-worker ports can be taken, necessitating another
34 # HUP after QUIT-ing the original master:
35 # server.listen("127.0.0.1:#{8081 + worker.nr}") rescue nil
37 :before_fork => lambda { |server, worker|
38 server.logger.info("worker=#{worker.nr} spawning...")
40 :before_exec => lambda { |server|
41 server.logger.info("forked child re-executing...")
44 :preload_app => false,
47 :stream_input => false,
50 attr_reader :config_file #:nodoc:
52 def initialize(defaults = {}) #:nodoc:
53 @set = Hash.new(:unset)
54 use_defaults = defaults.delete(:use_defaults)
55 @config_file = defaults.delete(:config_file)
57 @set.merge!(DEFAULTS) if use_defaults
58 defaults.each { |key, value| self.send(key, value) }
63 instance_eval(File.read(@config_file)) if @config_file
66 def commit!(server, options = {}) #:nodoc:
67 skip = options[:skip] || []
68 stream_input = @set.delete(:stream_input)
69 unless stream_input.nil?
70 Unicorn::HttpRequest::DEFAULTS[Const::STREAM_INPUT] = stream_input
72 @set.each do |key, value|
73 value == :unset and next
74 skip.include?(key) and next
76 if server.respond_to?(setter)
77 server.send(setter, value)
79 server.instance_variable_set("@#{key}", value)
88 # sets object to the +new+ Logger-like object. The new logger-like
89 # object must respond to the following methods:
90 # +debug+, +info+, +warn+, +error+, +fatal+, +close+
92 %w(debug info warn error fatal close).each do |m|
93 new.respond_to?(m) and next
94 raise ArgumentError, "logger=#{new} does not respond to method=#{m}"
100 # sets after_fork hook to a given block. This block will be called by
101 # the worker after forking. The following is an example hook which adds
102 # a per-process listener to every worker:
104 # after_fork do |server,worker|
105 # # per-process listener ports for debugging/admin:
106 # # "rescue nil" statement is needed because USR2 will
107 # # cause the master process to reexecute itself and the
108 # # per-worker ports can be taken, necessitating another
109 # # HUP after QUIT-ing the original master:
110 # server.listen("127.0.0.1:#{9293 + worker.nr}") rescue nil
112 # # drop permissions to "www-data" in the worker
113 # # generally there's no reason to start Unicorn as a priviledged user
114 # # as it is not recommended to expose Unicorn to public clients.
115 # uid, gid = Process.euid, Process.egid
116 # user, group = 'www-data', 'www-data'
117 # target_uid = Etc.getpwnam(user).uid
118 # target_gid = Etc.getgrnam(group).gid
119 # worker.tempfile.chown(target_uid, target_gid)
120 # if uid != target_uid || gid != target_gid
121 # Process.initgroups(user, target_gid)
122 # Process::GID.change_privilege(target_gid)
123 # Process::UID.change_privilege(target_uid)
126 def after_fork(*args, &block)
127 set_hook(:after_fork, block_given? ? block : args[0])
130 # sets before_fork got be a given Proc object. This Proc
131 # object will be called by the master process before forking
133 def before_fork(*args, &block)
134 set_hook(:before_fork, block_given? ? block : args[0])
137 # sets the before_exec hook to a given Proc object. This
138 # Proc object will be called by the master process right
139 # before exec()-ing the new unicorn binary. This is useful
140 # for freeing certain OS resources that you do NOT wish to
141 # share with the reexeced child process.
142 # There is no corresponding after_exec hook (for obvious reasons).
143 def before_exec(*args, &block)
144 set_hook(:before_exec, block_given? ? block : args[0], 1)
147 # sets the timeout of worker processes to +seconds+. Workers
148 # handling the request/app.call/response cycle taking longer than
149 # this time period will be forcibly killed (via SIGKILL). This
150 # timeout is enforced by the master process itself and not subject
151 # to the scheduling limitations by the worker process. Due the
152 # low-complexity, low-overhead implementation, timeouts of less
153 # than 3.0 seconds can be considered inaccurate and unsafe.
155 Numeric === seconds or raise ArgumentError,
156 "not numeric: timeout=#{seconds.inspect}"
157 seconds >= 3 or raise ArgumentError,
158 "too low: timeout=#{seconds.inspect}"
159 @set[:timeout] = seconds
162 # sets the current number of worker_processes to +nr+. Each worker
163 # process will serve exactly one client at a time.
164 def worker_processes(nr)
165 Integer === nr or raise ArgumentError,
166 "not an integer: worker_processes=#{nr.inspect}"
167 nr >= 0 or raise ArgumentError,
168 "not non-negative: worker_processes=#{nr.inspect}"
169 @set[:worker_processes] = nr
172 # sets listeners to the given +addresses+, replacing or augmenting the
173 # current set. This is for the global listener pool shared by all
174 # worker processes. For per-worker listeners, see the after_fork example
175 # This is for internal API use only, do not use it in your Unicorn
176 # config file. Use listen instead.
177 def listeners(addresses) # :nodoc:
178 Array === addresses or addresses = Array(addresses)
179 addresses.map! { |addr| expand_addr(addr) }
180 @set[:listeners] = addresses
183 # adds an +address+ to the existing listener set.
185 # The following options may be specified (but are generally not needed):
187 # +backlog+: this is the backlog of the listen() syscall.
189 # Some operating systems allow negative values here to specify the
190 # maximum allowable value. In most cases, this number is only
191 # recommendation and there are other OS-specific tunables and
192 # variables that can affect this number. See the listen(2)
193 # syscall documentation of your OS for the exact semantics of
196 # If you are running unicorn on multiple machines, lowering this number
197 # can help your load balancer detect when a machine is overloaded
198 # and give requests to a different machine.
202 # +rcvbuf+, +sndbuf+: maximum send and receive buffer sizes of sockets
204 # These correspond to the SO_RCVBUF and SO_SNDBUF settings which
205 # can be set via the setsockopt(2) syscall. Some kernels
206 # (e.g. Linux 2.4+) have intelligent auto-tuning mechanisms and
207 # there is no need (and it is sometimes detrimental) to specify them.
209 # See the socket API documentation of your operating system
210 # to determine the exact semantics of these settings and
211 # other operating system-specific knobs where they can be
214 # Defaults: operating system defaults
215 def listen(address, opt = { :backlog => 1024 })
216 address = expand_addr(address)
217 if String === address
218 Hash === @set[:listener_opts] or
219 @set[:listener_opts] = Hash.new { |hash,key| hash[key] = {} }
220 [ :backlog, :sndbuf, :rcvbuf ].each do |key|
221 value = opt[key] or next
223 raise ArgumentError, "not an integer: #{key}=#{value.inspect}"
225 @set[:listener_opts][address].merge!(opt)
228 @set[:listeners] = [] unless Array === @set[:listeners]
229 @set[:listeners] << address
232 # sets the +path+ for the PID file of the unicorn master process
233 def pid(path); set_path(:pid, path); end
235 # Enabling this preloads an application before forking worker
236 # processes. This allows memory savings when using a
237 # copy-on-write-friendly GC but can cause bad things to happen when
238 # resources like sockets are opened at load time by the master
239 # process and shared by multiple children. People enabling this are
240 # highly encouraged to look at the before_fork/after_fork hooks to
241 # properly close/reopen sockets. Files opened for logging do not
242 # have to be reopened as (unbuffered-in-userspace) files opened with
243 # the File::APPEND flag are written to atomically on UNIX.
245 # In addition to reloading the unicorn-specific config settings,
246 # SIGHUP will reload application code in the working
247 # directory/symlink when workers are gracefully restarted.
248 def preload_app(bool)
250 when TrueClass, FalseClass
251 @set[:preload_app] = bool
253 raise ArgumentError, "preload_app=#{bool.inspect} not a boolean"
257 # Allow applications to stream input as it is being read from the
258 # network directly to the application. Enabling this can allow
259 # real-time processing of request bodies as it is being sent by
260 # the client, useful for things like upload progress notification
261 # and tunneling arbitrary stream protocols via bidirectional chunked
263 # This may not work with all applications because some broken
264 # applications assume env['rack.input'].read(size) always returns
265 # the requested amount of data. This causes env['rack.input']#read
266 # to provide IO#readpartial semantics instead. Some applications
267 # may also fully receive an input and never attempt to process it,
268 # causing clients confusion when they receive a response after
269 # only a partial request has been sent.
270 def stream_input(bool)
272 when TrueClass, FalseClass
273 @set[:stream_input] = bool
275 raise ArgumentError, "stream_input=#{bool.inspect} not a boolean"
279 # Allow redirecting $stderr to a given path. Unlike doing this from
280 # the shell, this allows the unicorn process to know the path its
281 # writing to and rotate the file if it is used for logging. The
282 # file will be opened with the File::APPEND flag and writes
283 # synchronized to the kernel (but not necessarily to _disk_) so
284 # multiple processes can safely append to it.
285 def stderr_path(path)
286 set_path(:stderr_path, path)
289 # Same as stderr_path, except for $stdout
290 def stdout_path(path)
291 set_path(:stdout_path, path)
296 def set_path(var, path) #:nodoc:
300 path = File.expand_path(path)
301 File.writable?(File.dirname(path)) or \
302 raise ArgumentError, "directory for #{var}=#{path} not writable"
309 def set_hook(var, my_proc, req_arity = 2) #:nodoc:
312 arity = my_proc.arity
313 (arity == req_arity) or \
315 "#{var}=#{my_proc.inspect} has invalid arity: " \
316 "#{arity} (need #{req_arity})"
318 my_proc = DEFAULTS[var]
320 raise ArgumentError, "invalid type: #{var}=#{my_proc.inspect}"
325 # expands "unix:path/to/foo" to a socket relative to the current path
326 # expands pathnames of sockets if relative to "~" or "~username"
327 # expands "*:port and ":port" to "0.0.0.0:port"
328 def expand_addr(address) #:nodoc
329 return "0.0.0.0:#{address}" if Integer === address
330 return address unless String === address
333 when %r{\Aunix:(.*)\z}
336 File.expand_path(address)
337 when %r{\A(?:\*:)?(\d+)\z}
339 when %r{\A(.*):(\d+)\z}
340 # canonicalize the name
341 packed = Socket.pack_sockaddr_in($2.to_i, $1)
342 Socket.unpack_sockaddr_in(packed).reverse!.join(':')