Sync settings docs with gunicorn/config.py

docs/source/settings.rst

@@ -82,7 +82,7 @@ You'll want to vary this a bit to find the best for your particular
 application's work load.
 
 By default, the value of the ``WEB_CONCURRENCY`` environment variable.
-If it is not defined, the default is 1.
+If it is not defined, the default is ``1``.
 
 worker_class
 ~~~~~~~~~~~~
@@ -172,9 +172,7 @@ timeout
 * ``-t INT, --timeout INT``
 * ``30``
 
-A worker must notify the master process once per timeout interval.
+Workers silent for more than this many seconds are killed and restarted.
-If it fails do so, the worker is killed and a new worker is spawned
-to replace it.
 
 Generally set to thirty seconds. Only set this noticeably higher if
 you're sure of the repercussions for sync workers. For the non sync
@@ -246,8 +244,12 @@ limit_request_field_size
 
 Limit the allowed size of an HTTP request header field.
 
-Value is a number from 0 (unlimited) to 8190. to set the limit
+Value is a positive number or 0. Setting it to 0 will allow unlimited
-on the allowed size of an HTTP request header field.
+header field sizes.
+
+.. warning::
+   Setting this parameter to a very high or unlimited value can open
+   up for DDOS attacks.
 
 Debugging
 ---------
@@ -314,14 +316,19 @@ sendfile
 ~~~~~~~~
 
 * ``--no-sendfile``
-* ``True``
+* ``None``
 
 Disables the use of ``sendfile()``.
 
+If not set, the value of the ``SENDFILE`` environment variable is used
+to enable or disable its usage.
+
 .. versionadded:: 19.2
 .. versionchanged:: 19.4
    Swapped ``--sendfile`` with ``--no-sendfile`` to actually allow
    disabling.
+.. versionchanged:: 19.6
+   added support for the ``SENDFILE`` environment variable
 
 chdir
 ~~~~~
@@ -465,7 +472,10 @@ Front-end's IPs from which allowed to handle set secure headers.
 
 Set to ``*`` to disable checking of Front-end IPs (useful for setups
 where you don't know in advance the IP address of Front-end, but
-you still trust the environment)
+you still trust the environment).
+
+By default, the value of the ``FORWARDED_ALLOW_IPS`` environment
+variable. If it is not defined, the default is ``"127.0.0.1"``.
 
 Logging
 -------
@@ -488,30 +498,31 @@ access_log_format
 
 The access log format.
 
-==========  ===========
+===========  ===========
-Identifier  Description
+Identifier   Description
-==========  ===========
+===========  ===========
-h           remote address
+h            remote address
-l           ``'-'``
+l            ``'-'``
-u           user name
+u            user name
-t           date of the request
+t            date of the request
-r           status line (e.g. ``GET / HTTP/1.1``)
+r            status line (e.g. ``GET / HTTP/1.1``)
-m           request method
+m            request method
-U           URL path without query string
+U            URL path without query string
-q           query string
+q            query string
-H           protocol
+H            protocol
-s           status
+s            status
-B           response length
+B            response length
-b           response length or ``'-'`` (CLF format)
+b            response length or ``'-'`` (CLF format)
-f           referer
+f            referer
-a           user agent
+a            user agent
-T           request time in seconds
+T            request time in seconds
-D           request time in microseconds
+D            request time in microseconds
-L           request time in decimal seconds
+L            request time in decimal seconds
-p           process ID
+p            process ID
-{Header}i   request header
+{Header}i    request header
-{Header}o   response header
+{Header}o    response header
-==========  ===========
+{Variable}e  environment variable
+===========  ===========
 
 errorlog
 ~~~~~~~~
@@ -521,7 +532,7 @@ errorlog
 
 The Error log file to write to.
 
-``'-'`` means log to stderr.
+Using ``'-'`` for FILE makes gunicorn log to stderr.
 
 .. versionchanged:: 19.2
    Log to stderr by default.
@@ -553,10 +564,6 @@ The logger you want to use to log events in Gunicorn.
 The default class (``gunicorn.glogging.Logger``) handle most of
 normal usages in logging. It provides error and access logging.
 
-If you enable statsd support, then a special subclass
-(``gunicorn.instrument.statsd.Statsd``) is used instead, which handles
-sending the metrics to *statsd_host*
-
 You can provide your own worker by giving Gunicorn a
 Python path to a subclass like ``gunicorn.glogging.Logger``.
 Alternatively the syntax can also load the Logger class
@@ -621,7 +628,7 @@ enable_stdio_inheritance
 * ``-R, --enable-stdio-inheritance``
 * ``False``
 
-Enable stdio inheritance
+Enable stdio inheritance.
 
 Enable inheritance for stdio file descriptors in daemon mode.
 
@@ -636,12 +643,6 @@ statsd_host
 
 ``host:port`` of the statsd server to log to.
 
-Note: enabling this switches the default *logger_class* to
-``gunicorn.instrument.statsd.Statsd``. If you wish to use statsd with
-a custom *logger_class*, you should make sure your class is API
-compatible with ``gunicorn.instrument.statsd.Statsd``, or inherit from
-it.
-
 .. versionadded:: 19.1
 
 statsd_prefix
@@ -875,7 +876,7 @@ worker_exit
         def worker_exit(server, worker):
             pass
 
-Called in the worker, right before it terminates.
+Called just after a worker has been exited.
 
 The callable needs to accept two instance variables for the Arbiter and
 the just-exited Worker.