Class: Unicorn::Configurator

Inherits:
Object
  • Object
show all
Includes:
Unicorn
Defined in:
lib/unicorn/configurator.rb

Overview

Implements a simple DSL for configuring a unicorn server.

See unicorn.bogomips.org/examples/unicorn.conf.rb and unicorn.bogomips.org/examples/unicorn.conf.minimal.rb example configuration files. An example config file for use with nginx is also available at unicorn.bogomips.org/examples/nginx.conf

See the TUNING.html document for more information on tuning unicorn.

Constant Summary collapse

RACKUP =

used to stash stuff for deferred processing of cli options in config.ru after “working_directory” is bound. Do not rely on this being around later on…

{
  :daemonize => false,
  :host => Unicorn::Const::DEFAULT_HOST,
  :port => Unicorn::Const::DEFAULT_PORT,
  :set_listener => false,
  :options => { :listeners => [] }
}
DEFAULTS =

Default settings for Unicorn

{
  :timeout => 60,
  :logger => Logger.new($stderr),
  :worker_processes => 1,
  :after_fork => lambda { |server, worker|
      server.logger.info("worker=#{worker.nr} spawned pid=#{$$}")
    },
  :before_fork => lambda { |server, worker|
      server.logger.info("worker=#{worker.nr} spawning...")
    },
  :before_exec => lambda { |server|
      server.logger.info("forked child re-executing...")
    },
  :pid => nil,
  :preload_app => false,
  :check_client_connection => false,
  :rewindable_input => true, # for Rack 2.x: (Rack::VERSION[0] <= 1),
  :client_body_buffer_size => Unicorn::Const::MAX_BODY,
}

Constants included from Unicorn

ClientShutdown

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Unicorn

builder, listener_names, log_error, pipe

Constructor Details

#initialize(defaults = {}) ⇒ Configurator

:startdoc:


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# File 'lib/unicorn/configurator.rb', line 52

def initialize(defaults = {}) #:nodoc:
  self.set = Hash.new(:unset)
  @use_defaults = defaults.delete(:use_defaults)
  self.config_file = defaults.delete(:config_file)

  # after_reload is only used by unicorn_rails, unsupported otherwise
  self.after_reload = defaults.delete(:after_reload)

  set.merge!(DEFAULTS) if @use_defaults
  defaults.each { |key, value| self.__send__(key, value) }
  Hash === set[:listener_opts] or
      set[:listener_opts] = Hash.new { |hash,key| hash[key] = {} }
  Array === set[:listeners] or set[:listeners] = []
  reload(false)
end

Instance Attribute Details

#after_reloadObject

:stopdoc:


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# File 'lib/unicorn/configurator.rb', line 17

def after_reload
  @after_reload
end

#config_fileObject

:stopdoc:


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# File 'lib/unicorn/configurator.rb', line 17

def config_file
  @config_file
end

#setObject

:stopdoc:


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# File 'lib/unicorn/configurator.rb', line 17

def set
  @set
end

Instance Method Details

#[](key) ⇒ Object

:nodoc:


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# File 'lib/unicorn/configurator.rb', line 112

def [](key) # :nodoc:
  set[key]
end

#after_fork(*args, &block) ⇒ Object

sets after_fork hook to a given block. This block will be called by the worker after forking. The following is an example hook which adds a per-process listener to every worker:

after_fork do |server,worker|
  # per-process listener ports for debugging/admin:
  addr = "127.0.0.1:#{9293 + worker.nr}"

  # the negative :tries parameter indicates we will retry forever
  # waiting on the existing process to exit with a 5 second :delay
  # Existing options for Unicorn::Configurator#listen such as
  # :backlog, :rcvbuf, :sndbuf are available here as well.
  server.listen(addr, :tries => -1, :delay => 5, :backlog => 128)
end

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# File 'lib/unicorn/configurator.rb', line 150

def after_fork(*args, &block)
  set_hook(:after_fork, block_given? ? block : args[0])
end

#before_exec(*args, &block) ⇒ Object

sets the before_exec hook to a given Proc object. This Proc object will be called by the master process right before exec()-ing the new unicorn binary. This is useful for freeing certain OS resources that you do NOT wish to share with the reexeced child process. There is no corresponding after_exec hook (for obvious reasons).


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# File 'lib/unicorn/configurator.rb', line 167

def before_exec(*args, &block)
  set_hook(:before_exec, block_given? ? block : args[0], 1)
end

#before_fork(*args, &block) ⇒ Object

sets before_fork got be a given Proc object. This Proc object will be called by the master process before forking each worker.


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# File 'lib/unicorn/configurator.rb', line 157

def before_fork(*args, &block)
  set_hook(:before_fork, block_given? ? block : args[0])
end

#check_client_connection(bool) ⇒ Object

When enabled, unicorn will check the client connection by writing the beginning of the HTTP headers before calling the application.

This will prevent calling the application for clients who have disconnected while their connection was queued.

This only affects clients connecting over Unix domain sockets and TCP via loopback (127...*). It is unlikely to detect disconnects if the client is on a remote host (even on a fast LAN).

This option cannot be used in conjunction with :tcp_nopush.


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# File 'lib/unicorn/configurator.rb', line 498

def check_client_connection(bool)
  set_bool(:check_client_connection, bool)
end

#client_body_buffer_size(bytes) ⇒ Object

The maximum size (in bytes) to buffer in memory before resorting to a temporary file. Default is 112 kilobytes. This option has no effect if “rewindable_input” is set to false.


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# File 'lib/unicorn/configurator.rb', line 483

def client_body_buffer_size(bytes)
  set_int(:client_body_buffer_size, bytes, 0)
end

#commit!(server, options = {}) ⇒ Object

:nodoc:


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# File 'lib/unicorn/configurator.rb', line 92

def commit!(server, options = {}) #:nodoc:
  skip = options[:skip] || []
  if ready_pipe = RACKUP.delete(:ready_pipe)
    server.ready_pipe = ready_pipe
  end
  if set[:check_client_connection]
    set[:listeners].each do |address|
      if set[:listener_opts][address][:tcp_nopush] == true
        raise ArgumentError,
          "check_client_connection is incompatible with tcp_nopush:true"
      end
    end
  end
  set.each do |key, value|
    value == :unset and next
    skip.include?(key) and next
    server.__send__("#{key}=", value)
  end
end

#expand_addr(address) ⇒ Object

expands “unix:path/to/foo” to a socket relative to the current path expands pathnames of sockets if relative to “~” or “~username” expands “*:port and ”:port“ to ”0.0.0.0:port“


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# File 'lib/unicorn/configurator.rb', line 560

def expand_addr(address) #:nodoc:
  return "0.0.0.0:#{address}" if Integer === address
  return address unless String === address

  case address
  when %r{\Aunix:(.*)\z}
    File.expand_path($1)
  when %r{\A~}
    File.expand_path(address)
  when %r{\A(?:\*:)?(\d+)\z}
    "0.0.0.0:#$1"
  when %r{\A\[([a-fA-F0-9:]+)\]\z}, %r/\A((?:\d+\.){3}\d+)\z/
    canonicalize_tcp($1, 80)
  when %r{\A\[([a-fA-F0-9:]+)\]:(\d+)\z}, %r{\A(.*):(\d+)\z}
    canonicalize_tcp($1, $2.to_i)
  else
    address
  end
end

#listen(address, options = {}) ⇒ Object

Adds an address to the existing listener set. May be specified more than once. address may be an Integer port number for a TCP port, an “IP_ADDRESS:PORT” for TCP listeners or a pathname for UNIX domain sockets.

listen 3000 # listen to port 3000 on all TCP interfaces
listen "127.0.0.1:3000"  # listen to port 3000 on the loopback interface
listen "/path/to/.unicorn.sock" # listen on the given Unix domain socket
listen "[::1]:3000" # listen to port 3000 on the IPv6 loopback interface

When using Unix domain sockets, be sure: 1) the path matches the one used by nginx 2) uses the same filesystem namespace as the nginx process For systemd users using PrivateTmp=true (for either nginx or unicorn), this means Unix domain sockets must not be placed in /tmp

The following options may be specified (but are generally not needed):

:backlog => number of clients

This is the backlog of the listen() syscall.

Some operating systems allow negative values here to specify the maximum allowable value. In most cases, this number is only recommendation and there are other OS-specific tunables and variables that can affect this number. See the listen(2) syscall documentation of your OS for the exact semantics of this.

If you are running unicorn on multiple machines, lowering this number can help your load balancer detect when a machine is overloaded and give requests to a different machine.

Default: 1024

Note: with the Linux kernel, the net.core.somaxconn sysctl defaults to 128, capping this value to 128. Raising the sysctl allows a larger backlog (which may not be desirable with multiple, load-balanced machines).

:rcvbuf => bytes, :sndbuf => bytes

Maximum receive and send buffer sizes (in bytes) of sockets.

These correspond to the SO_RCVBUF and SO_SNDBUF settings which can be set via the setsockopt(2) syscall. Some kernels (e.g. Linux 2.4+) have intelligent auto-tuning mechanisms and there is no need (and it is sometimes detrimental) to specify them.

See the socket API documentation of your operating system to determine the exact semantics of these settings and other operating system-specific knobs where they can be specified.

Defaults: operating system defaults

:tcp_nodelay => true or false

Disables Nagle's algorithm on TCP sockets if true.

Setting this to true can make streaming responses in Rails 3.1 appear more quickly at the cost of slightly higher bandwidth usage. The effect of this option is most visible if nginx is not used, but nginx remains highly recommended with unicorn.

This has no effect on UNIX sockets.

Default: true (Nagle's algorithm disabled) in unicorn This defaulted to false in unicorn 3.x

:tcp_nopush => true or false

Enables/disables TCP_CORK in Linux or TCP_NOPUSH in FreeBSD

This prevents partial TCP frames from being sent out and reduces wakeups in nginx if it is on a different machine. Since unicorn is only designed for applications that send the response body quickly without keepalive, sockets will always be flushed on close to prevent delays.

This has no effect on UNIX sockets.

Default: false This defaulted to true in unicorn 3.4 - 3.7

:ipv6only => true or false

This option makes IPv6-capable TCP listeners IPv6-only and unable to receive IPv4 queries on dual-stack systems. A separate IPv4-only listener is required if this is true.

Enabling this option for the IPv6-only listener and having a separate IPv4 listener is recommended if you wish to support IPv6 on the same TCP port. Otherwise, the value of env will appear as an ugly IPv4-mapped-IPv6 address for IPv4 clients (e.g “:ffff:10.0.0.1” instead of just “10.0.0.1”).

Default: Operating-system dependent

:reuseport => true or false

This enables multiple, independently-started unicorn instances to bind to the same port (as long as all the processes enable this).

This option must be used when unicorn first binds the listen socket. It cannot be enabled when a socket is inherited via SIGUSR2 (but it will remain on if inherited), and it cannot be enabled directly via SIGHUP.

Note: there is a chance of connections being dropped if one of the unicorn instances is stopped while using this.

This is supported on *BSD systems and Linux 3.9 or later.

ref: lwn.net/Articles/542629/

Default: false (unset)

:tries => Integer

Times to retry binding a socket if it is already in use

A negative number indicates we will retry indefinitely, this is useful for migrations and upgrades when individual workers are binding to different ports.

Default: 5

:delay => seconds

Seconds to wait between successive tries

Default: 0.5 seconds

:umask => mode

Sets the file mode creation mask for UNIX sockets. If specified, this is usually in octal notation.

Typically UNIX domain sockets are created with more liberal file permissions than the rest of the application. By default, we create UNIX domain sockets to be readable and writable by all local users to give them the same accessibility as locally-bound TCP listeners.

This has no effect on TCP listeners.

Default: 0000 (world-read/writable)

:tcp_defer_accept => Integer

Defer accept() until data is ready (Linux-only)

For Linux 2.6.32 and later, this is the number of retransmits to defer an accept() for if no data arrives, but the client will eventually be accepted after the specified number of retransmits regardless of whether data is ready.

For Linux before 2.6.32, this is a boolean option, and accepts are always deferred indefinitely if no data arrives. This is similar to :accept_filter => "dataready" under FreeBSD.

Specifying true is synonymous for the default value(s) below, and false or nil is synonymous for a value of zero.

A value of 1 is a good optimization for local networks and trusted clients. There is no good reason to ever disable this with a zero value with unicorn.

Default: 1

:accept_filter => String

defer accept() until data is ready (FreeBSD-only)

This enables either the “dataready” or (default) “httpready” accept() filter under FreeBSD. This is intended as an optimization to reduce context switches with common GET/HEAD requests.

There is no good reason to change from the default.

Default: “httpready”


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# File 'lib/unicorn/configurator.rb', line 406

def listen(address, options = {})
  address = expand_addr(address)
  if String === address
    [ :umask, :backlog, :sndbuf, :rcvbuf, :tries ].each do |key|
      value = options[key] or next
      Integer === value or
        raise ArgumentError, "not an integer: #{key}=#{value.inspect}"
    end
    [ :tcp_nodelay, :tcp_nopush, :ipv6only, :reuseport ].each do |key|
      (value = options[key]).nil? and next
      TrueClass === value || FalseClass === value or
        raise ArgumentError, "not boolean: #{key}=#{value.inspect}"
    end
    unless (value = options[:delay]).nil?
      Numeric === value or
        raise ArgumentError, "not numeric: delay=#{value.inspect}"
    end
    set[:listener_opts][address].merge!(options)
  end

  set[:listeners] << address
end

#listeners(addresses) ⇒ Object

sets listeners to the given addresses, replacing or augmenting the current set. This is for the global listener pool shared by all worker processes. For per-worker listeners, see the after_fork example This is for internal API use only, do not use it in your Unicorn config file. Use listen instead.


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# File 'lib/unicorn/configurator.rb', line 217

def listeners(addresses) # :nodoc:
  Array === addresses or addresses = Array(addresses)
  addresses.map! { |addr| expand_addr(addr) }
  set[:listeners] = addresses
end

#logger(obj) ⇒ Object

sets object to the obj Logger-like object. The new Logger-like object must respond to the following methods:

  • debug

  • info

  • warn

  • error

  • fatal

The default Logger will log its output to the path specified by stderr_path. If you're running Unicorn daemonized, then you must specify a path to prevent error messages from going to /dev/null.


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# File 'lib/unicorn/configurator.rb', line 127

def logger(obj)
  %w(debug info warn error fatal).each do |m|
    obj.respond_to?(m) and next
    raise ArgumentError, "logger=#{obj} does not respond to method=#{m}"
  end

  set[:logger] = obj
end

#pid(path) ⇒ Object

sets the path for the PID file of the unicorn master process


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# File 'lib/unicorn/configurator.rb', line 430

def pid(path); set_path(:pid, path); end

#preload_app(bool) ⇒ Object

Enabling this preloads an application before forking worker processes. This allows memory savings when using a copy-on-write-friendly GC but can cause bad things to happen when resources like sockets are opened at load time by the master process and shared by multiple children. People enabling this are highly encouraged to look at the before_fork/after_fork hooks to properly close/reopen sockets. Files opened for logging do not have to be reopened as (unbuffered-in-userspace) files opened with the File::APPEND flag are written to atomically on UNIX.

In addition to reloading the unicorn-specific config settings, SIGHUP will reload application code in the working directory/symlink when workers are gracefully restarted when preload_app=false (the default). As reloading the application sometimes requires RubyGems updates, Gem.refresh is always called before the application is loaded (for RubyGems users).

During deployments, care should always be taken to ensure your applications are properly deployed and running. Using preload_app=false (the default) means you must check if your application is responding properly after a deployment. Improperly deployed applications can go into a spawn loop if the application fails to load. While your children are in a spawn loop, it is is possible to fix an application by properly deploying all required code and dependencies. Using preload_app=true means any application load error will cause the master process to exit with an error.


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# File 'lib/unicorn/configurator.rb', line 460

def preload_app(bool)
  set_bool(:preload_app, bool)
end

#reload(merge_defaults = true) ⇒ Object

:nodoc:


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# File 'lib/unicorn/configurator.rb', line 68

def reload(merge_defaults = true) #:nodoc:
  if merge_defaults && @use_defaults
    set.merge!(DEFAULTS) if @use_defaults
  end
  instance_eval(File.read(config_file), config_file) if config_file

  parse_rackup_file

  RACKUP[:set_listener] and
    set[:listeners] << "#{RACKUP[:host]}:#{RACKUP[:port]}"

  # unicorn_rails creates dirs here after working_directory is bound
  after_reload.call if after_reload

  # working_directory binds immediately (easier error checking that way),
  # now ensure any paths we changed are correctly set.
  [ :pid, :stderr_path, :stdout_path ].each do |var|
    String === (path = set[var]) or next
    path = File.expand_path(path)
    File.writable?(path) || File.writable?(File.dirname(path)) or \
          raise ArgumentError, "directory for #{var}=#{path} not writable"
  end
end

#rewindable_input(bool) ⇒ Object

Toggles making env rewindable. Disabling rewindability can improve performance by lowering I/O and memory usage for applications that accept uploads. Keep in mind that the Rack 1.x spec requires env to be rewindable, so this allows intentionally violating the current Rack 1.x spec.

rewindable_input defaults to true when used with Rack 1.x for Rack conformance. When Rack 2.x is finalized, this will most likely default to false while still conforming to the newer (less demanding) spec.


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# File 'lib/unicorn/configurator.rb', line 475

def rewindable_input(bool)
  set_bool(:rewindable_input, bool)
end

#stderr_path(path) ⇒ Object

Allow redirecting $stderr to a given path. Unlike doing this from the shell, this allows the unicorn process to know the path its writing to and rotate the file if it is used for logging. The file will be opened with the File::APPEND flag and writes synchronized to the kernel (but not necessarily to disk) so multiple processes can safely append to it.

If you are daemonizing and using the default logger, it is important to specify this as errors will otherwise be lost to /dev/null. Some applications/libraries may also triggering warnings that go to stderr, and they will end up here.


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# File 'lib/unicorn/configurator.rb', line 513

def stderr_path(path)
  set_path(:stderr_path, path)
end

#stdout_path(path) ⇒ Object

Same as stderr_path, except for $stdout. Not many Rack applications write to $stdout, but any that do will have their output written here. It is safe to point this to the same location a stderr_path. Like stderr_path, this defaults to /dev/null when daemonized.


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# File 'lib/unicorn/configurator.rb', line 521

def stdout_path(path)
  set_path(:stdout_path, path)
end

#timeout(seconds) ⇒ Object

sets the timeout of worker processes to seconds. Workers handling the request/app.call/response cycle taking longer than this time period will be forcibly killed (via SIGKILL). This timeout is enforced by the master process itself and not subject to the scheduling limitations by the worker process. Due the low-complexity, low-overhead implementation, timeouts of less than 3.0 seconds can be considered inaccurate and unsafe.

For running Unicorn behind nginx, it is recommended to set “fail_timeout=0” for in your nginx configuration like this to have nginx always retry backends that may have had workers SIGKILL-ed due to timeouts.

# See http://wiki.nginx.org/NginxHttpUpstreamModule for more details
# on nginx upstream configuration:
upstream unicorn_backend {
  # for UNIX domain socket setups:
  server unix:/path/to/.unicorn.sock fail_timeout=0;

  # for TCP setups
  server 192.168.0.7:8080 fail_timeout=0;
  server 192.168.0.8:8080 fail_timeout=0;
  server 192.168.0.9:8080 fail_timeout=0;
}

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# File 'lib/unicorn/configurator.rb', line 195

def timeout(seconds)
  set_int(:timeout, seconds, 3)
  # POSIX says 31 days is the smallest allowed maximum timeout for select()
  max = 30 * 60 * 60 * 24
  set[:timeout] = seconds > max ? max : seconds
end

#user(user, group = nil) ⇒ Object

Runs worker processes as the specified user and group. The master process always stays running as the user who started it. This switch will occur after calling the after_fork hook, and only if the Worker#user method is not called in the after_fork hook group is optional and will not change if unspecified.


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# File 'lib/unicorn/configurator.rb', line 550

def user(user, group = nil)
  # raises ArgumentError on invalid user/group
  Etc.getpwnam(user)
  Etc.getgrnam(group) if group
  set[:user] = [ user, group ]
end

#worker_processes(nr) ⇒ Object

sets the current number of worker_processes to nr. Each worker process will serve exactly one client at a time. You can increment or decrement this value at runtime by sending SIGTTIN or SIGTTOU respectively to the master process without reloading the rest of your Unicorn configuration. See the SIGNALS document for more information.


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# File 'lib/unicorn/configurator.rb', line 208

def worker_processes(nr)
  set_int(:worker_processes, nr, 1)
end

#working_directory(path) ⇒ Object

sets the working directory for Unicorn. This ensures SIGUSR2 will start a new instance of Unicorn in this directory. This may be a symlink, a common scenario for Capistrano users. Unlike all other Unicorn configuration directives, this binds immediately for error checking and cannot be undone by unsetting it in the configuration file and reloading.


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# File 'lib/unicorn/configurator.rb', line 531

def working_directory(path)
  # just let chdir raise errors
  path = File.expand_path(path)
  if config_file &&
     config_file[0] != ?/ &&
     ! File.readable?("#{path}/#{config_file}")
    raise ArgumentError,
          "config_file=#{config_file} would not be accessible in" \
          " working_directory=#{path}"
  end
  Dir.chdir(path)
  Unicorn::HttpServer::START_CTX[:cwd] = ENV["PWD"] = path
end