class Puma::DSL

The methods that are available for use inside the config file. These same methods are used in Puma cli and the rack handler internally.

Used manually (via CLI class):

config = Configuration.new({}) do |user_config|
  user_config.port 3001
end
config.load

puts config.options[:binds]
"tcp://127.0.0.1:3001"

Used to load file:

$ cat puma_config.rb
  port 3002

config = Configuration.new(config_file: "puma_config.rb")
config.load

puts config.options[:binds]
# => "tcp://127.0.0.1:3002"

Detailed docs can be found in `examples/config.rb`

Public Class Methods

new(options, config) click to toggle source
# File lib/puma/dsl.rb, line 33
def initialize(options, config)
  @config  = config
  @options = options

  @plugins = []
end

Public Instance Methods

_load_from(path) click to toggle source
# File lib/puma/dsl.rb, line 40
def _load_from(path)
  if path
    @path = path
    instance_eval(File.read(path), path, 1)
  end
ensure
  _offer_plugins
end
_offer_plugins() click to toggle source
# File lib/puma/dsl.rb, line 49
def _offer_plugins
  @plugins.each do |o|
    if o.respond_to? :config
      @options.shift
      o.config self
    end
  end

  @plugins.clear
end
activate_control_app(url="auto", opts={}) click to toggle source

Start the Puma control rack app on url. This app can be communicated with to control the main server.

# File lib/puma/dsl.rb, line 96
def activate_control_app(url="auto", opts={})
  if url == "auto"
    path = Configuration.temp_path
    @options[:control_url] = "unix://#{path}"
    @options[:control_url_temp] = path
  else
    @options[:control_url] = url
  end

  if opts[:no_token]
    auth_token = :none
  else
    auth_token = opts[:auth_token]
    auth_token ||= Configuration.random_token
  end

  @options[:control_auth_token] = auth_token
  @options[:control_url_umask] = opts[:umask] if opts[:umask]
end
after_worker_boot(&block)
Alias for: after_worker_fork
after_worker_fork(&block) click to toggle source

*Cluster mode only* Code to run in the master after it starts a worker.

This can be called multiple times to add hooks.

# File lib/puma/dsl.rb, line 371
def after_worker_fork(&block)
  @options[:after_worker_fork] ||= []
  @options[:after_worker_fork] = block
end
Also aliased as: after_worker_boot
app(obj=nil, &block) click to toggle source

Use obj or block as the Rack app. This allows a config file to be the app itself.

# File lib/puma/dsl.rb, line 85
def app(obj=nil, &block)
  obj ||= block

  raise "Provide either a #call'able or a block" unless obj

  @options[:app] = obj
end
before_fork(&block) click to toggle source

*Cluster mode only* Code to run immediately before master process forks workers (once on boot). These hooks can block if necessary to wait for background operations unknown to puma to finish before the process terminates. This can be used to close any connections to remote servers (database, redis, …) that were opened when preloading the code

This can be called multiple times to add hooks.

# File lib/puma/dsl.rb, line 329
def before_fork(&block)
  @options[:before_fork] ||= []
  @options[:before_fork] << block
end
bind(url) click to toggle source

Adds a binding for the server to url. tcp://, unix://, and ssl:// are the only accepted protocols. Use query parameters within the url to specify options.

@note multiple urls can be bound to, calling `bind` does not overwrite previous bindings.

@example Explicitly the socket backlog depth (default is 1024)

bind('unix:///var/run/puma.sock?backlog=2048')

@example Set up ssl cert

bind('ssl://127.0.0.1:9292?key=key.key&cert=cert.pem')

@example Prefer low-latency over higher throughput (via `Socket::TCP_NODELAY`)

bind('tcp://0.0.0.0:9292?low_latency=true')

@example Set socket permissions

bind('unix:///var/run/puma.sock?umask=0111')
# File lib/puma/dsl.rb, line 139
def bind(url)
  @options[:binds] ||= []
  @options[:binds] << url
end
clean_thread_locals(which=true) click to toggle source

Work around leaky apps that leave garbage in Thread locals across requests

# File lib/puma/dsl.rb, line 171
def clean_thread_locals(which=true)
  @options[:clean_thread_locals] = which
end
clear_binds!() click to toggle source
# File lib/puma/dsl.rb, line 144
def clear_binds!
  @options[:binds] = []
end
daemonize(which=true) click to toggle source

Daemonize the server into the background. Highly suggest that this be combined with pidfile and stdout_redirect.

# File lib/puma/dsl.rb, line 177
def daemonize(which=true)
  @options[:daemon] = which
end
debug() click to toggle source

Show debugging info

# File lib/puma/dsl.rb, line 251
def debug
  @options[:debug] = true
end
default_host() click to toggle source
# File lib/puma/dsl.rb, line 64
def default_host
  @options[:default_host] || Configuration::DefaultTCPHost
end
directory(dir) click to toggle source

The directory to operate out of.

# File lib/puma/dsl.rb, line 379
def directory(dir)
  @options[:directory] = dir.to_s
end
drain_on_shutdown(which=true) click to toggle source

When shutting down, drain the accept socket of pending connections and process them. This loops over the accept socket until there are no more read events and then stops looking and waits for the requests to finish.

# File lib/puma/dsl.rb, line 185
def drain_on_shutdown(which=true)
  @options[:drain_on_shutdown] = which
end
early_hints(answer=true) click to toggle source
# File lib/puma/dsl.rb, line 267
def early_hints(answer=true)
  @options[:early_hints] = answer
end
environment(environment) click to toggle source

Set the environment in which the Rack's app will run.

# File lib/puma/dsl.rb, line 190
def environment(environment)
  @options[:environment] = environment
end
first_data_timeout(seconds) click to toggle source

Define how long the tcp socket stays open, if no data has been received

# File lib/puma/dsl.rb, line 164
def first_data_timeout(seconds)
  @options[:first_data_timeout] = Integer(seconds)
end
force_shutdown_after(val=:forever) click to toggle source

How long to wait for threads to stop when shutting them down. Defaults to :forever. Specifying :immediately will cause Puma to kill the threads immediately. Otherwise the value is the number of seconds to wait.

Puma always waits a few seconds after killing a thread for it to try to finish up it's work, even in :immediately mode.

# File lib/puma/dsl.rb, line 201
def force_shutdown_after(val=:forever)
  i = case val
      when :forever
        -1
      when :immediately
        0
      else
        Integer(val)
      end

  @options[:force_shutdown_after] = i
end
get(key,default=nil) click to toggle source
# File lib/puma/dsl.rb, line 72
def get(key,default=nil)
  @options[key.to_sym] || default
end
inject(&blk) click to toggle source
# File lib/puma/dsl.rb, line 68
def inject(&blk)
  instance_eval(&blk)
end
load(file) click to toggle source

Load additional configuration from a file Files get loaded later via Configuration#load

# File lib/puma/dsl.rb, line 118
def load(file)
  @options[:config_files] ||= []
  @options[:config_files] << file
end
log_requests(which=true) click to toggle source

Enable request logging

# File lib/puma/dsl.rb, line 245
def log_requests(which=true)
  @options[:log_requests] = which
end
lowlevel_error_handler(obj=nil, &block) click to toggle source

Use obj or block as the low level error handler. This allows a config file to change the default error on the server.

# File lib/puma/dsl.rb, line 405
def lowlevel_error_handler(obj=nil, &block)
  obj ||= block
  raise "Provide either a #call'able or a block" unless obj
  @options[:lowlevel_error_handler] = obj
end
on_restart(&block) click to toggle source

Code to run before doing a restart. This code should close logfiles, database connections, etc.

This can be called multiple times to add code each time.

# File lib/puma/dsl.rb, line 219
def on_restart(&block)
  @options[:on_restart] ||= []
  @options[:on_restart] << block
end
on_worker_boot(&block) click to toggle source

*Cluster mode only* Code to run in a worker when it boots to setup the process before booting the app.

This can be called multiple times to add hooks.

# File lib/puma/dsl.rb, line 339
def on_worker_boot(&block)
  @options[:before_worker_boot] ||= []
  @options[:before_worker_boot] << block
end
on_worker_fork(&block) click to toggle source

*Cluster mode only* Code to run in the master when it is about to create the worker by forking itself.

This can be called multiple times to add hooks.

# File lib/puma/dsl.rb, line 361
def on_worker_fork(&block)
  @options[:before_worker_fork] ||= []
  @options[:before_worker_fork] << block
end
on_worker_shutdown(&block) click to toggle source

*Cluster mode only* Code to run immediately before a worker shuts down (after it has finished processing HTTP requests). These hooks can block if necessary to wait for background operations unknown to puma to finish before the process terminates.

This can be called multiple times to add hooks.

# File lib/puma/dsl.rb, line 351
def on_worker_shutdown(&block)
  @options[:before_worker_shutdown] ||= []
  @options[:before_worker_shutdown] << block
end
persistent_timeout(seconds) click to toggle source

Define how long persistent connections can be idle before puma closes them

# File lib/puma/dsl.rb, line 158
def persistent_timeout(seconds)
  @options[:persistent_timeout] = Integer(seconds)
end
pidfile(path) click to toggle source

Store the pid of the server in the file at path.

# File lib/puma/dsl.rb, line 233
def pidfile(path)
  @options[:pidfile] = path.to_s
end
plugin(name) click to toggle source

Load the named plugin for use by this configuration

# File lib/puma/dsl.rb, line 78
def plugin(name)
  @plugins << @config.load_plugin(name)
end
port(port, host=nil) click to toggle source

Define the TCP port to bind to. Use bind for more advanced options.

# File lib/puma/dsl.rb, line 150
def port(port, host=nil)
  host ||= default_host
  bind "tcp://#{host}:#{port}"
end
preload_app!(answer=true) click to toggle source

*Cluster mode only* Preload the application before starting the workers and setting up the listen ports. This conflicts with using the phased restart feature, you can't use both.

# File lib/puma/dsl.rb, line 398
def preload_app!(answer=true)
  @options[:preload_app] = answer
end
prune_bundler(answer=true) click to toggle source

This option is used to allow your app and its gems to be properly reloaded when not using preload.

When set, if puma detects that it's been invoked in the context of Bundler, it will cleanup the environment and re-run itself outside the Bundler environment, but directly using the files that Bundler has setup.

This means that puma is now decoupled from your Bundler context and when each worker loads, it will be loading a new Bundler context and thus can float around as the release dictates.

# File lib/puma/dsl.rb, line 423
def prune_bundler(answer=true)
  @options[:prune_bundler] = answer
end
queue_requests(answer=true) click to toggle source

When set to true (the default), workers accept all requests and queue them before passing them to the handlers. When set to false, each worker process accepts exactly as many requests as it is configured to simultaneously handle.

Queueing requests generally improves performance. In some cases, such as a single threaded application, it may be better to ensure requests get balanced across workers.

Note that setting this to false disables HTTP keepalive and slow clients will occupy a handler thread while the request is being sent. A reverse proxy, such as nginx, can handle slow clients and queue requests before they reach puma.

# File lib/puma/dsl.rb, line 463
def queue_requests(answer=true)
  @options[:queue_requests] = answer
end
quiet(which=true) click to toggle source

Disable request logging.

# File lib/puma/dsl.rb, line 239
def quiet(which=true)
  @options[:log_requests] = !which
end
rackup(path) click to toggle source

Load path as a rackup file.

# File lib/puma/dsl.rb, line 257
def rackup(path)
  @options[:rackup] = path.to_s
end
restart_command(cmd) click to toggle source

Command to use to restart puma. This should be just how to load puma itself (ie. 'ruby -Ilib bin/puma'), not the arguments to puma, as those are the same as the original process.

# File lib/puma/dsl.rb, line 228
def restart_command(cmd)
  @options[:restart_cmd] = cmd.to_s
end
set_default_host(host) click to toggle source
# File lib/puma/dsl.rb, line 60
def set_default_host(host)
  @options[:default_host] = host
end
set_remote_address(val=:socket) click to toggle source

Control how the remote address of the connection is set. This is configurable because to calculate the true socket peer address a kernel syscall is required which for very fast rack handlers slows down the handling significantly.

There are 4 possible values:

  • :socket (the default) - read the peername from the socket using the

    syscall. This is the normal behavior.
  • :localhost - set the remote address to “127.0.0.1”

  • header: http_header - set the remote address to the value of the

    provided http header. For instance:
    `set_remote_address header: "X-Real-IP"`.
    Only the first word (as separated by spaces or comma)
    is used, allowing headers such as X-Forwarded-For
    to be used as well.
  • Any string - this allows you to hardcode remote address to any value

    you wish. Because puma never uses this field anyway, it's
    format is entirely in your hands.
# File lib/puma/dsl.rb, line 493
def set_remote_address(val=:socket)
  case val
  when :socket
    @options[:remote_address] = val
  when :localhost
    @options[:remote_address] = :value
    @options[:remote_address_value] = "127.0.0.1".freeze
  when String
    @options[:remote_address] = :value
    @options[:remote_address_value] = val
  when Hash
    if hdr = val[:header]
      @options[:remote_address] = :header
      @options[:remote_address_header] = "HTTP_" + hdr.upcase.tr("-", "_")
    else
      raise "Invalid value for set_remote_address - #{val.inspect}"
    end
  else
    raise "Invalid value for set_remote_address - #{val}"
  end
end
shutdown_debug(val=true) click to toggle source

When a shutdown is requested, the backtraces of all the threads will be written to $stdout. This can help figure out why shutdown is hanging.

# File lib/puma/dsl.rb, line 470
def shutdown_debug(val=true)
  @options[:shutdown_debug] = val
end
ssl_bind(host, port, opts) click to toggle source
# File lib/puma/dsl.rb, line 296
def ssl_bind(host, port, opts)
  verify = opts.fetch(:verify_mode, 'none')

  if defined?(JRUBY_VERSION)
    keystore_additions = "keystore=#{opts[:keystore]}&keystore-pass=#{opts[:keystore_pass]}"
    bind "ssl://#{host}:#{port}?cert=#{opts[:cert]}&key=#{opts[:key]}&#{keystore_additions}&verify_mode=#{verify}"
  else
    bind "ssl://#{host}:#{port}?cert=#{opts[:cert]}&key=#{opts[:key]}&verify_mode=#{verify}"
  end
end
state_path(path) click to toggle source

Use path as the file to store the server info state. This is used by pumactl to query and control the server.

# File lib/puma/dsl.rb, line 310
def state_path(path)
  @options[:state] = path.to_s
end
stdout_redirect(stdout=nil, stderr=nil, append=false) click to toggle source

Redirect STDOUT and STDERR to files specified.

# File lib/puma/dsl.rb, line 272
def stdout_redirect(stdout=nil, stderr=nil, append=false)
  @options[:redirect_stdout] = stdout
  @options[:redirect_stderr] = stderr
  @options[:redirect_append] = append
end
tag(string) click to toggle source

Additional text to display in process listing

# File lib/puma/dsl.rb, line 428
def tag(string)
  @options[:tag] = string.to_s
end
tcp_mode() click to toggle source

Run the app as a raw TCP app instead of an HTTP rack app

# File lib/puma/dsl.rb, line 390
def tcp_mode
  @options[:mode] = :tcp
end
tcp_mode!() click to toggle source

Run Puma in TCP mode

# File lib/puma/dsl.rb, line 263
def tcp_mode!
  @options[:mode] = :tcp
end
threads(min, max) click to toggle source

Configure min to be the minimum number of threads to use to answer requests and max the maximum.

# File lib/puma/dsl.rb, line 281
def threads(min, max)
  min = Integer(min)
  max = Integer(max)
  if min > max
    raise "The minimum (#{min}) number of threads must be less than or equal to the max (#{max})"
  end

  if max < 1
    raise "The maximum number of threads (#{max}) must be greater than 0"
  end

  @options[:min_threads] = min
  @options[:max_threads] = max
end
worker_boot_timeout(timeout) click to toggle source

*Cluster mode only* Set the timeout for workers to boot

# File lib/puma/dsl.rb, line 441
def worker_boot_timeout(timeout)
  @options[:worker_boot_timeout] = Integer(timeout)
end
worker_directory(dir) click to toggle source

DEPRECATED: The directory to operate out of.

# File lib/puma/dsl.rb, line 384
def worker_directory(dir)
  $stderr.puts "worker_directory is deprecated. Please use `directory`"
  directory dir
end
worker_shutdown_timeout(timeout) click to toggle source

*Cluster mode only* Set the timeout for worker shutdown

# File lib/puma/dsl.rb, line 446
def worker_shutdown_timeout(timeout)
  @options[:worker_shutdown_timeout] = Integer(timeout)
end
worker_timeout(timeout) click to toggle source

*Cluster mode only* Set the timeout for workers in seconds When set the master process will terminate any workers that have not checked in within the given timeout. This mitigates hung processes. Default value is 60 seconds.

# File lib/puma/dsl.rb, line 436
def worker_timeout(timeout)
  @options[:worker_timeout] = Integer(timeout)
end
workers(count) click to toggle source

*Cluster mode only* How many worker processes to run.

# File lib/puma/dsl.rb, line 316
def workers(count)
  @options[:workers] = count.to_i
end