HttpHeadersMoreModule

= Name =

ngx_headers_more - Set and clear input and output headers...more than "add"!

This module is not distributed with the Nginx source. See the installation instructions.

= Version =

This document describes headers-more-nginx-module v0.25 released on 10 January 2014.

= Synopsis =

# set the Server output header more_set_headers 'Server: my-server';

# set and clear output headers location /bar { more_set_headers 'X-MyHeader: blah' 'X-MyHeader2: foo'; more_set_headers -t 'text/plain text/css' 'Content-Type: text/foo'; more_set_headers -s '400 404 500 503' -s 413 'Foo: Bar'; more_clear_headers 'Content-Type'; # your proxy_pass/memcached_pass/or any other config goes here... }

# set output headers location /type { more_set_headers 'Content-Type: text/plain'; # ...   }

# set input headers location /foo { set $my_host 'my dog'; more_set_input_headers 'Host: $my_host'; more_set_input_headers -t 'text/plain' 'X-Foo: bah'; # now $host and $http_host have their new values...       # ... }

# replace input header X-Foo *only* if it already exists more_set_input_headers -r 'X-Foo: howdy';

= Description =

This module allows you to add, set, or clear any output or input header that you specify.

This is an enhanced version of the standard headers module because it provides more utilities like resetting or clearing "builtin headers" like , , and.

It also allows you to specify an optional HTTP status code criteria using the  option and an optional content type criteria using the  option while modifying the output headers with the more_set_headers and more_clear_headers directives. For example,

more_set_headers -s 404 -t 'text/html' 'X-Foo: Bar';

Input headers can be modified as well. For example

location /foo { more_set_input_headers 'Host: foo' 'User-Agent: faked'; # now $host, $http_host, $user_agent, and #  $http_user_agent all have their new values. }

The option  is also available in the more_set_input_headers and more_clear_input_headers directives (for request header filtering) while the  option is not allowed.

Unlike the standard headers module, this module's directives will by default apply to all the status codes, including  and.

= Directives =

more_set_headers
syntax: ''more_set_headers [-t ]... [-s ]... ...''

default: no

context: http, server, location, location if

phase: output-header-filter

Adds or replaces the specified output headers when the response status code matches the codes specified by the  option AND the response content type matches the types specified by the   option.

If either  or   is not specified or has an empty list value, then no match is required. Therefore, the following directive set the  output header to the custom value for any status code and any content type:

more_set_headers   "Server: my_server";

A single directive can set/add multiple output headers. For example

more_set_headers 'Foo: bar' 'Baz: bah';

Multiple occurrences of the options are allowed in a single directive. Their values will be merged together. For instance

more_set_headers -s 404 -s '500 503' 'Foo: bar';

is equivalent to

more_set_headers -s '404 500 503' 'Foo: bar';

The new header should be the one of the forms:



The last two effectively clear the value of the header.

Nginx variables are allowed in header values. For example:

set $my_var "dog"; more_set_headers "Server: $my_var";

But variables won't work in header keys due to performance considerations.

Multiple set/clear header directives are allowed in a single location, and they're executed sequentially.

Directives inherited from an upper level scope (say, http block or server blocks) are executed before the directives in the location block.

Note that although  is allowed in location if blocks, it is not allowed in the server if blocks, as in

? # This is NOT allowed! ? server { ?     if ($args ~ 'download') { ?         more_set_headers 'Foo: Bar'; ?     }      ?      ...      ?  }

Behind the scene, use of this directive and its friend more_clear_headers will (lazily) register an ouput header filter that modifies  the way you specify.

more_clear_headers
syntax: ''more_clear_headers [-t ]... [-s ]... ...''

default: no

context: http, server, location, location if

phase: output-header-filter

Clears the specified output headers.

In fact,

more_clear_headers -s 404 -t 'text/plain' Foo Baz;

is exactly equivalent to

more_set_headers -s 404 -t 'text/plain' "Foo: " "Baz: ";

or

more_set_headers -s 404 -t 'text/plain' Foo Baz

See more_set_headers for more details.

Wildcard  can also be used to specify a header name pattern. For example, the following directive effectively clears any output headers starting by " ":

more_clear_headers 'X-Hidden-*';

The  wildcard support was first introduced in v0.09.

more_set_input_headers
syntax: ''more_set_input_headers [-r] [-t ]... ...''

default: no

context: http, server, location, location if

phase: rewrite tail

Very much like more_set_headers except that it operates on input headers (or request headers) and it only supports the  option.

Note that using the  option in this directive means filtering by the   request header, rather than the response header.

Behind the scene, use of this directive and its friend more_clear_input_headers will (lazily) register a  handler that modifies   the way you specify. Note that it always run at the end of the  so that it runs after the standard rewrite module and works in subrequests as well.

If the  option is specified, then the headers will be replaced to the new values only if they already exist.

more_clear_input_headers
syntax: ''more_clear_input_headers [-t ]... ...''

default: no

context: http, server, location, location if

phase: rewrite tail

Clears the specified input headers.

In fact,

more_clear_input_headers -s 404 -t 'text/plain' Foo Baz;

is exactly equivalent to

more_set_input_headers -s 404 -t 'text/plain' "Foo: " "Baz: ";

or

more_set_input_headers -s 404 -t 'text/plain' Foo Baz

See more_set_input_headers for more details.

= Limitations =


 * Unlike the standard headers module, this module does not automatically take care of the constraint among the,  , and   headers. You have to get them right yourself or use the headers module together with this module.
 * You cannot remove the  response header using this module because the   response header is generated by the standard   in the Nginx core, whose output header filter runs always after the filter of this module. The only way to actually remove the   header is to patch the Nginx core, that is, editing the C function   in the   file.

= Installation =

Grab the nginx source code from nginx.org, for example, the version 1.5.8 (see nginx compatibility), and then build the source with this module:

wget 'http://nginx.org/download/nginx-1.5.8.tar.gz' tar -xzvf nginx-1.5.8.tar.gz   cd nginx-1.5.8/ # Here we assume you would install you nginx under /opt/nginx/. ./configure --prefix=/opt/nginx \ --add-module=/path/to/headers-more-nginx-module make make install

Download the latest version of the release tarball of this module from headers-more-nginx-module file list.

Also, this module is included and enabled by default in the ngx_openresty bundle.

= Compatibility =

The following versions of Nginx should work with this module:


 * 1.5.x                      (last tested: 1.5.8)
 * 1.4.x                      (last tested: 1.4.4)
 * 1.3.x                      (last tested: 1.3.7)
 * 1.2.x                      (last tested: 1.2.9)
 * 1.1.x                      (last tested: 1.1.5)
 * 1.0.x                      (last tested: 1.0.11)
 * 0.9.x                      (last tested: 0.9.4)
 * 0.8.x                      (last tested: 0.8.54)
 * 0.7.x >= 0.7.44            (last tested: 0.7.68)

Earlier versions of Nginx like 0.6.x and 0.5.x will not work.

If you find that any particular version of Nginx above 0.7.44 does not work with this module, please consider reporting a bug.

= Community =

English Mailing List
The openresty-en mailing list is for English speakers.

Chinese Mailing List
The openresty mailing list is for Chinese speakers.

= Bugs and Patches =

Please submit bug reports, wishlists, or patches by


 * 1) creating a ticket on the GitHub Issue Tracker,
 * 2) or posting to the OpenResty community.

= Source Repository =

Available on github at agentzh/headers-more-nginx-module.

= Changes =

The changes of every release of this module can be obtained from the ngx_openresty bundle's change logs:

http://openresty.org/#Changes

= Test Suite =

This module comes with a Perl-driven test suite. The test cases are declarative too. Thanks to the Test::Nginx module in the Perl world.

To run it on your side:

$ PATH=/path/to/your/nginx-with-headers-more-module:$PATH prove -r t

To run the test suite with valgrind's memcheck, use the following commands:

$ export PATH=/path/to/your/nginx-with-headers-more-module:$PATH $ TEST_NGINX_USE_VALGRIND=1 prove -r t

You need to terminate any Nginx processes before running the test suite if you have changed the Nginx server binary.

Because a single nginx server (by default, ) is used across all the test scripts (  files), it's meaningless to run the test suite in parallel by specifying   when invoking the   utility.

Some parts of the test suite requires modules proxy, rewrite, and echo to be enabled as well when building Nginx.

= TODO =


 * Support variables in new headers' keys.

= Getting involved =

You'll be very welcomed to submit patches to the author or just ask for a commit bit to the source repository on GitHub.

= Authors =


 * Yichun "agentzh" Zhang (章亦春) , CloudFlare Inc.
 * Bernd Dorn ( http://www.lovelysystems.com/ )

This wiki page is also maintained by the author himself, and everybody is encouraged to improve this page as well.

= Copyright & License =

The code base is borrowed directly from the standard headers module in Nginx 0.8.24. This part of code is copyrighted by Igor Sysoev.

Copyright (c) 2009-2014, Yichun "agentzh" Zhang (章亦春) , CloudFlare Inc.

Copyright (c) 2010-2013, Bernd Dorn.

This module is licensed under the terms of the BSD license.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:


 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

= See Also =


 * The original thread on the Nginx mailing list that inspires this module's development: "A question about add_header replication".
 * The orginal announcement thread on the Nginx mailing list: "The "headers_more" module: Set and clear output headers...more than 'add'!".
 * The original blog post about this module's initial development.
 * The echo module for Nginx module's automated testing.
 * The standard headers module.