0b152383e04dbeb10dba29bcdfaa0981e4d9df27Simon Ulbricht<?xml version="1.0"?>

0b152383e04dbeb10dba29bcdfaa0981e4d9df27Simon Ulbricht<!DOCTYPE modulesynopsis SYSTEM "/style/modulesynopsis.dtd">

0b152383e04dbeb10dba29bcdfaa0981e4d9df27Simon Ulbricht<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>

98890889ffb2e8f6f722b00e265a211f13b5a861Corneliu-Claudiu Prodescu

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht<modulesynopsis metafile="mod_proxy.xml.meta">

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht

d815d2b83e945875100ceca322ebd50d96714206Simon Ulbricht<name>mod_proxy</name>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht<description>HTTP/1.1 proxy/gateway server</description>

6150196e8d99f7161a622fdc1a872fecd378195fSimon Ulbricht<status>Extension</status>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht<sourcefile>mod_proxy.c</sourcefile>

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder<identifier>proxy_module</identifier>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht

3209c34f23fb83a86fbbdd6501db6d4bfb949a57Simon Ulbricht<summary>

2643008447e30b6025f742eb6a661f38be756b1eSimon Ulbricht <note type="warning"><title>Warning</title>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>Do not enable proxying with <directive module="mod_proxy"

2643008447e30b6025f742eb6a661f38be756b1eSimon Ulbricht >ProxyRequests</directive> until you have <a href="#access"

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht >secured your server</a>. Open proxy servers are dangerous both to your

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht network and to the Internet at large.</p>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht </note>

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder <p>This module implements a proxy/gateway for Apache. It implements

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder proxying capability for <code>AJP13</code> (Apache JServe Protocol

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder version 1.3), <code>FTP</code>, <code>CONNECT</code> (for SSL),

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder <code>HTTP/0.9</code>, <code>HTTP/1.0</code>, and <code>HTTP/1.1</code>.

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder The module can be configured to connect to other proxy modules for these

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder and other protocols.</p>

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder <p>Apache's proxy features are divided into several modules in

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht addition to <module>mod_proxy</module>:

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder <module>mod_proxy_http</module>, <module>mod_proxy_ftp</module>,

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder <module>mod_proxy_ajp</module>, <module>mod_proxy_balancer</module>,

9da6e0cb2ea6e43f5b09dcd2a9af5468a5d0fcf4Christian Maeder and <module>mod_proxy_connect</module>. Thus, if you want to use

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht one or more of the particular proxy functions, load

6150196e8d99f7161a622fdc1a872fecd378195fSimon Ulbricht <module>mod_proxy</module> <em>and</em> the appropriate module(s)

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht into the server (either statically at compile-time or dynamically

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht via the <directive module="mod_so">LoadModule</directive>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht directive).</p>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht <p>In addition, extended features are provided by other modules.

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht Caching is provided by <module>mod_cache</module> and related

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht modules. The ability to contact remote servers using the SSL/TLS

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht protocol is provided by the <code>SSLProxy*</code> directives of

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht <module>mod_ssl</module>. These additional modules will need

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht to be loaded and configured to take advantage of these features.</p>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht</summary>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht<seealso><module>mod_cache</module></seealso>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht<seealso><module>mod_proxy_http</module></seealso>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht<seealso><module>mod_proxy_ftp</module></seealso>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht<seealso><module>mod_proxy_connect</module></seealso>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht<seealso><module>mod_proxy_balancer</module></seealso>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht<seealso><module>mod_ssl</module></seealso>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht <section id="forwardreverse"><title>Forward and Reverse Proxies</title>

6a26171b5bc5b6ec3e1b02ae30dcfb6f03d7ffefSimon Ulbricht <p>Apache can be configured in both a <dfn>forward</dfn> and

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht <dfn>reverse</dfn> proxy mode.</p>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht <p>An ordinary <dfn>forward proxy</dfn> is an intermediate

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht server that sits between the client and the <em>origin

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht server</em>. In order to get content from the origin server,

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht the client sends a request to the proxy naming the origin server

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht as the target and the proxy then requests the content from the

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht origin server and returns it to the client. The client must be

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht specially configured to use the forward proxy to access other

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht sites.</p>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht <p>A typical usage of a forward proxy is to provide Internet

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht access to internal clients that are otherwise restricted by a

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht firewall. The forward proxy can also use caching (as provided

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht by <module>mod_cache</module>) to reduce network usage.</p>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>The forward proxy is activated using the <directive

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht module="mod_proxy">ProxyRequests</directive> directive. Because

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht forward proxies allow clients to access arbitrary sites through

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht your server and to hide their true origin, it is essential that

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht you <a href="#access">secure your server</a> so that only

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht authorized clients can access the proxy before activating a

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht forward proxy.</p>

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht <p>A <dfn>reverse proxy</dfn>, by contrast, appears to the

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht client just like an ordinary web server. No special

432ac7c08e2592af0660e026051ffb052e88a100Simon Ulbricht configuration on the client is necessary. The client makes

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht ordinary requests for content in the name-space of the reverse

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht proxy. The reverse proxy then decides where to send those

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht requests, and returns the content as if it was itself the

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht origin.</p>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht <p>A typical usage of a reverse proxy is to provide Internet

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht users access to a server that is behind a firewall. Reverse

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht proxies can also be used to balance load among several back-end

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht servers, or to provide caching for a slower back-end server.

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht In addition, reverse proxies can be used simply to bring

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht several servers into the same URL space.</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

6a26171b5bc5b6ec3e1b02ae30dcfb6f03d7ffefSimon Ulbricht <p>A reverse proxy is activated using the <directive

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht module="mod_proxy">ProxyPass</directive> directive or the

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht <code>[P]</code> flag to the <directive

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht module="mod_rewrite">RewriteRule</directive> directive. It is

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht <strong>not</strong> necessary to turn <directive

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht module="mod_proxy">ProxyRequests</directive> on in order to

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht configure a reverse proxy.</p>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht </section> <!-- /forwardreverse -->

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht <section id="examples"><title>Basic Examples</title>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht <p>The examples below are only a very basic idea to help you

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht get started. Please read the documentation on the individual

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht directives.</p>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht <p>In addition, if you wish to have caching enabled, consult

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht the documentation from <module>mod_cache</module>.</p>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht <example><title>Forward Proxy</title>

abea93ed557b22ea833e1524ee5ca11afc12208aSimon Ulbricht ProxyRequests On<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht ProxyVia On<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht &lt;Proxy *&gt;<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <indent>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht Order deny,allow<br />

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht Deny from all<br />

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht Allow from internal.example.com<br />

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht </indent>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht &lt;/Proxy&gt;

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht </example>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <example><title>Reverse Proxy</title>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht ProxyRequests Off<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht &lt;Proxy *&gt;<br />

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht <indent>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht Order deny,allow<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht Allow from all<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </indent>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht &lt;/Proxy&gt;<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht ProxyPass /foo http://foo.example.com/bar<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht ProxyPassReverse /foo http://foo.example.com/bar

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </example>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </section> <!-- /examples -->

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <section id="access"><title>Controlling access to your proxy</title>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>You can control who can access your proxy via the <directive

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht module="mod_proxy" type="section">Proxy</directive> control block as in

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht the following example:</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <example>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht &lt;Proxy *&gt;<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <indent>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht Order Deny,Allow<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht Deny from all<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht Allow from 192.168.0<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </indent>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht &lt;/Proxy&gt;

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </example>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>For more information on access control directives, see

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <module>mod_authz_host</module>.</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>Strictly limiting access is essential if you are using a

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht forward proxy (using the <directive

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht module="mod_proxy">ProxyRequests</directive> directive).

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht Otherwise, your server can be used by any client to access

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht arbitrary hosts while hiding his or her true identity. This is

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht dangerous both for your network and for the Internet at large.

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht When using a reverse proxy (using the <directive

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht module="mod_proxy">ProxyPass</directive> directive with

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <code>ProxyRequests Off</code>), access control is less

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht critical because clients can only contact the hosts that you

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht have specifically configured.</p>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht <p><strong>See Also</strong> the <a href="mod_proxy_http.html#env"

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht >Proxy-Chain-Auth</a> environment variable.</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </section> <!-- /access -->

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <section id="startup"><title>Slow Startup</title>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>If you're using the <directive module="mod_proxy"

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht >ProxyBlock</directive> directive, hostnames' IP addresses are looked up

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht and cached during startup for later match test. This may take a few

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht seconds (or more) depending on the speed with which the hostname lookups

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht occur.</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </section> <!-- /startup -->

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <section id="intranet"><title>Intranet Proxy</title>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht <p>An Apache proxy server situated in an intranet needs to forward

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht external requests through the company's firewall (for this, configure

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht the <directive module="mod_proxy">ProxyRemote</directive> directive

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht to forward the respective <var>scheme</var> to the firewall proxy).

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht However, when it has to

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht access resources within the intranet, it can bypass the firewall when

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht accessing hosts. The <directive module="mod_proxy">NoProxy</directive>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht directive is useful for specifying which hosts belong to the intranet and

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht should be accessed directly.</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>Users within an intranet tend to omit the local domain name from their

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht WWW requests, thus requesting "http://somehost/" instead of

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht <code>http://somehost.example.com/</code>. Some commercial proxy servers

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht let them get away with this and simply serve the request, implying a

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht configured local domain. When the <directive module="mod_proxy"

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht >ProxyDomain</directive> directive is used and the server is <a

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht href="#proxyrequests">configured for proxy service</a>, Apache can return

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht a redirect response and send the client to the correct, fully qualified,

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht server address. This is the preferred method since the user's bookmark

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht files will then contain fully qualified hosts.</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </section> <!-- /intranet -->

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <section id="envsettings"><title>Protocol Adjustments</title>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>For circumstances where <module>mod_proxy</module> is sending

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht requests to an origin server that doesn't properly implement

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht keepalives or HTTP/1.1, there are two <a

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht href="/env.html">environment variables</a> that can force the

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht request to use HTTP/1.0 with no keepalive. These are set via the

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <directive module="mod_env">SetEnv</directive> directive.</p>

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht <p>These are the <code>force-proxy-request-1.0</code> and

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <code>proxy-nokeepalive</code> notes.</p>

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht <example>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht &lt;Location /buggyappserver/&gt;<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <indent>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht ProxyPass http://buggyappserver:7001/foo/<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht SetEnv force-proxy-request-1.0 1<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht SetEnv proxy-nokeepalive 1<br />

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </indent>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht &lt;/Location&gt;

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht </example>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </section> <!-- /envsettings -->

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <section id="request-bodies"><title>Request Bodies</title>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <p>Some request methods such as POST include a request body.

987c9ee1092c7fd8b53242abefe4f3cf8e9a1011Simon Ulbricht The HTTP protocol requires that requests which include a body

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht either use chunked transfer encoding or send a

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht <code>Content-Length</code> request header. When passing these

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht requests on to the origin server, <module>mod_proxy_http</module>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht will always attempt to send the <code>Content-Length</code>. But

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht if the body is large and the original request used chunked

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht encoding, then chunked encoding may also be used in the upstream

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht request. You can control this selection using <a

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht href="/env.html">environment variables</a>. Setting

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht <code>proxy-sendcl</code> ensures maximum compatibility with

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht upstream servers by always sending the

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht <code>Content-Length</code>, while setting

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht <code>proxy-sendchunked</code> minimizes resource usage by using

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht chunked encoding.</p>

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht </section> <!-- /request-bodies -->

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht <section id="x-headers"><title>Reverse Proxy Request Headers</title>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <p>When acting in a reverse-proxy mode (using the <directive

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht module="mod_proxy">ProxyPass</directive> directive, for example),

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <module>mod_proxy_http</module> adds several request headers in

987c9ee1092c7fd8b53242abefe4f3cf8e9a1011Simon Ulbricht order to pass information to the origin server. These headers

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht are:</p>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <dl>

7c84f8fd92ed59eb2b9a674e6b1ea93c0f945006Simon Ulbricht <dt><code>X-Forwarded-For</code></dt>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <dd>The IP address of the client.</dd>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <dt><code>X-Forwarded-Host</code></dt>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <dd>The original host requested by the client in the <code>Host</code>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht HTTP request header.</dd>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <dt><code>X-Forwarded-Server</code></dt>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <dd>The hostname of the proxy server.</dd>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht </dl>

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht

53d3b5d18cae658f0e54872ade90ab5259b52b95Simon Ulbricht <p>Be careful when using these headers on the origin server, since

a210c2e5add831cd438183c8602ed8e610922beaSimon Ulbricht they will contain more than one (comma-separated) value if the

1651c7f5055453e18a8c34f96c333e2aa702a34eSimon Ulbricht original request already contained one of these headers. For

369771f5d48a40eda134026b1f45f63b2c00bdb8Simon Ulbricht example, you can use <code>%{X-Forwarded-For}i</code> in the log

987c9ee1092c7fd8b53242abefe4f3cf8e9a1011Simon Ulbricht format string of the origin server to log the original clients IP

address, but you may get more than one address if the request

passes through several proxies.</p>

<p>See also the <directive

module="mod_proxy">ProxyPreserveHost</directive> and <directive

module="mod_proxy">ProxyVia</directive> directives, which control

other request headers.</p>

</section> <!--/x-headers -->

<directivesynopsis type="section">

<name>Proxy</name>

<description>Container for directives applied to proxied resources</description>

<syntax>&lt;Proxy <var>wildcard-url</var>&gt; ...&lt;/Proxy&gt;</syntax>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>Directives placed in <directive type="section">Proxy</directive>

sections apply only to matching proxied content. Shell-style wildcards are

allowed.</p>

<p>For example, the following will allow only hosts in

<code>yournetwork.example.com</code> to access content via your proxy

server:</p>

<example>

&lt;Proxy *&gt;<br />

<indent>

Order Deny,Allow<br />

Deny from all<br />

Allow from yournetwork.example.com<br />

</indent>

&lt;/Proxy&gt;

</example>

<p>The following example will process all files in the <code>foo</code>

directory of <code>example.com</code> through the <code>INCLUDES</code>

filter when they are sent through the proxy server:</p>

<example>

&lt;Proxy http://example.com/foo/*&gt;<br />

<indent>

SetOutputFilter INCLUDES<br />

</indent>

&lt;/Proxy&gt;

</example>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyBadHeader</name>

<description>Determines how to handle bad header lines in a

response</description>

<syntax>ProxyBadHeader IsError|Ignore|StartBody</syntax>

<default>ProxyBadHeader IsError</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<compatibility>Available in Apache 2.0.44 and later</compatibility>

<usage>

<p>The <directive>ProxyBadHeader</directive> directive determines the

behaviour of <module>mod_proxy</module> if it receives syntactically invalid

header lines (<em>i.e.</em> containing no colon). The following arguments

are possible:</p>

<dl>

<dt><code>IsError</code></dt>

<dd>Abort the request and end up with a 502 (Bad Gateway) response. This is

the default behaviour.</dd>

<dt><code>Ignore</code></dt>

<dd>Treat bad header lines as if they weren't sent.</dd>

<dt><code>StartBody</code></dt>

<dd>When receiving the first bad header line, finish reading the headers and

treat the remainder as body. This helps to work around buggy backend servers

which forget to insert an empty line between the headers and the body.</dd>

</dl>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyFtpDirCharset</name>

<description>Define the character set for proxied FTP listings</description>

<syntax>ProxyFtpDirCharset <var>character set</var></syntax>

<default>ProxyFtpDirCharset ISO-8859-1</default>

<contextlist><context>server config</context><context>virtual host</context>

<context>directory</context></contextlist>

<compatibility>Available in Apache 2.2.7 and later</compatibility>

<usage>

<p>The <directive>ProxyFtpDirCharset</directive> directive defines the

character set to be set for FTP directory listings in HTML generated by

<module>mod_proxy_ftp</module>.</p>

</usage>

</directivesynopsis>

<directivesynopsis type="section">

<name>ProxyMatch</name>

<description>Container for directives applied to regular-expression-matched

proxied resources</description>

<syntax>&lt;ProxyMatch <var>regex</var>&gt; ...&lt;/ProxyMatch&gt;</syntax>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>The <directive type="section">ProxyMatch</directive> directive is

identical to the <directive module="mod_proxy"

type="section">Proxy</directive> directive, except it matches URLs

using <glossary ref="regex">regular expressions</glossary>.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyPreserveHost</name>

<description>Use incoming Host HTTP request header for proxy

request</description>

<syntax>ProxyPreserveHost On|Off</syntax>

<default>ProxyPreserveHost Off</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<compatibility>Available in Apache 2.0.31 and later.</compatibility>

<usage>

<p>When enabled, this option will pass the Host: line from the incoming

request to the proxied host, instead of the hostname specified in the

<directive>ProxyPass</directive> line.</p>

<p>This option should normally be turned <code>Off</code>. It is mostly

useful in special configurations like proxied mass name-based virtual

hosting, where the original Host header needs to be evaluated by the

backend server.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyRequests</name>

<description>Enables forward (standard) proxy requests</description>

<syntax>ProxyRequests On|Off</syntax>

<default>ProxyRequests Off</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>This allows or prevents Apache from functioning as a forward proxy

server. (Setting ProxyRequests to <code>Off</code> does not disable use of

the <directive module="mod_proxy">ProxyPass</directive> directive.)</p>

<p>In a typical reverse proxy configuration, this option should be set to

<code>Off</code>.</p>

<p>In order to get the functionality of proxying HTTP or FTP sites, you

need also <module>mod_proxy_http</module> or <module>mod_proxy_ftp</module>

(or both) present in the server.</p>

<note type="warning"><title>Warning</title>

<p>Do not enable proxying with <directive

module="mod_proxy">ProxyRequests</directive> until you have <a

href="#access">secured your server</a>. Open proxy servers are dangerous

both to your network and to the Internet at large.</p>

</note>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyRemote</name>

<description>Remote proxy used to handle certain requests</description>

<syntax>ProxyRemote <var>match</var> <var>remote-server</var></syntax>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>This defines remote proxies to this proxy. <var>match</var> is either the

name of a URL-scheme that the remote server supports, or a partial URL

for which the remote server should be used, or <code>*</code> to indicate

the server should be contacted for all requests. <var>remote-server</var> is

a partial URL for the remote server. Syntax:</p>

<example>

<dfn>remote-server</dfn> =

<var>scheme</var>://<var>hostname</var>[:<var>port</var>]

</example>

<p><var>scheme</var> is effectively the protocol that should be used to

communicate with the remote server; only <code>http</code> is supported by

this module.</p>

<example><title>Example</title>

ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000<br />

ProxyRemote * http://cleversite.com<br />

ProxyRemote ftp http://ftpproxy.mydomain.com:8080

</example>

<p>In the last example, the proxy will forward FTP requests, encapsulated

as yet another HTTP proxy request, to another proxy which can handle

them.</p>

<p>This option also supports reverse proxy configuration - a backend

webserver can be embedded within a virtualhost URL space even if that

server is hidden by another forward proxy.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyRemoteMatch</name>

<description>Remote proxy used to handle requests matched by regular

expressions</description>

<syntax>ProxyRemoteMatch <var>regex</var> <var>remote-server</var></syntax>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>The <directive>ProxyRemoteMatch</directive> is identical to the

<directive module="mod_proxy">ProxyRemote</directive> directive, except the

first argument is a <glossary ref="regex">regular expression</glossary>

match against the requested URL.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>BalancerMember</name>

<description>Add a member to a load balancing group</description>

<syntax>BalancerMember <var>url</var> [<var

>key=value [key=value ...]]</var></syntax>

<contextlist><context>directory</context>

</contextlist>

<compatibility>BalancerMember is only available in Apache 2.2

and later.</compatibility>

<usage>

<p>This directive adds a member to a load balancing group. It must be used

within a <code>&lt;Proxy <var>balancer://</var>...&gt;</code> container

directive, and can take any of the parameters available to

<directive module="mod_proxy">ProxyPass</directive> directives.</p>

<p>One additional parameter is available only to <directive

module="mod_proxy">BalancerMember</directive> directives:

<var>loadfactor</var>. This is the member load factor - a number between 1

(default) and 100, which defines the weighted load to be applied to the

member in question.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxySet</name>

<description>Set various Proxy balancer or member parameters</description>

<syntax>ProxySet <var>url</var> <var>key=value [key=value ...]</var></syntax>

<contextlist><context>directory</context>

</contextlist>

<compatibility>ProxySet is only available in Apache 2.2

and later.</compatibility>

<usage>

<p>This directive is used as an alternate method of setting any of the

parameters available to Proxy balancers and workers normally done via the

<directive module="mod_proxy">ProxyPass</directive> directive. If used

within a <code>&lt;Proxy <var>balancer url|worker url</var>&gt;</code>

container directive, the <var>url</var> argument is not required. As a side

effect the respective balancer or worker gets created. This can be useful

when doing reverse proxying via a

<directive module="mod_rewrite">RewriteRule</directive> instead of a

<directive module="mod_proxy">ProxyPass</directive> directive.</p>

<example>

&lt;Proxy balancer://hotcluster&gt;<br />

<indent>

BalancerMember http://www2.example.com:8009 loadfactor=1<br />

BalancerMember http://www3.example.com:8009 loadfactor=2<br />

ProxySet lbmethod=bytraffic<br />

</indent>

&lt;/Proxy&gt;

</example>

<example>

&lt;Proxy http://backend&gt;<br />

<indent>

ProxySet keepalive=On<br />

</indent>

&lt;/Proxy&gt;

</example>

<example>

ProxySet balancer://foo lbmethod=bytraffic timeout=15

</example>

<example>

ProxySet ajp://backend:7001 timeout=15

</example>

<note type="warning"><title>Warning</title>

<p>Keep in mind that the same parameter key can have a different meaning

depending whether it is applied to a balancer or a worker as shown by the two

examples above regarding timeout.</p>

</note>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyPass</name>

<description>Maps remote servers into the local server URL-space</description>

<syntax>ProxyPass [<var>path</var>] !|<var>url</var> [<var>key=value</var>

<var>[key=value</var> ...]] [nocanon] [interpolate]</syntax>

<contextlist><context>server config</context><context>virtual host</context>

<context>directory</context>

</contextlist>

<usage>

<p>This directive allows remote servers to be mapped into the space of

the local server; the local server does not act as a proxy in the

conventional sense, but appears to be a mirror of the remote

server. <var>path</var> is the name of a local virtual path; <var>url</var>

is a partial URL for the remote server and cannot include a query

string.</p>

<note type="warning">The <directive

module="mod_proxy">ProxyRequests</directive> directive should

usually be set <strong>off</strong> when using

<directive>ProxyPass</directive>.</note>

<p>Suppose the local server has address <code>http://example.com/</code>;

then</p>

<example>

ProxyPass /mirror/foo/ http://backend.example.com/

</example>

<p>will cause a local request for

<code>http://example.com/mirror/foo/bar</code> to be internally converted

into a proxy request to <code>http://backend.example.com/bar</code>.</p>

<note type="warning">

<p>If the first argument ends with a trailing <strong>/</strong>, the second

argument should also end with a trailing <strong>/</strong> and vice

versa. Otherwise the resulting requests to the backend may miss some

needed slashes and do not deliver the expected results.

</p>

</note>

<p>The <code>!</code> directive is useful in situations where you don't want

to reverse-proxy a subdirectory, <em>e.g.</em></p>

<example>

ProxyPass /mirror/foo/i !<br />

ProxyPass /mirror/foo http://backend.example.com

</example>

<p>will proxy all requests to <code>/mirror/foo</code> to

<code>backend.example.com</code> <em>except</em> requests made to

<code>/mirror/foo/i</code>.</p>

<note><title>Note</title>

<p>Order is important: exclusions must come <em>before</em> the

general <directive>ProxyPass</directive> directive.</p>

</note>

<p>As of Apache 2.1, the ability to use pooled connections to a backend

server is available. Using the <code>key=value</code> parameters it is

possible to tune this connection pooling. The default for a <code>Hard

Maximum</code> for the number of connections is the number of threads per

process in the active MPM. In the Prefork MPM, this is always 1, while with

the Worker MPM it is controlled by the

<directive>ThreadsPerChild</directive>.</p>

<p>Setting <code>min</code> will determine how many connections will always

be open to the backend server. Upto the Soft Maximum or <code>smax</code>

number of connections will be created on demand. Any connections above

<code>smax</code> are subject to a time to live or <code>ttl</code>. Apache

will never create more than the Hard Maximum or <code>max</code> connections

to the backend server.</p>

<example>

ProxyPass /example http://backend.example.com smax=5 max=20 ttl=120 retry=300

</example>

<table>

<tr><th>Parameter</th>

<th>Default</th>

<th>Description</th></tr>

<tr><td>min</td>

<td>0</td>

<td>Minimum number of connections that will always

be open to the backend server.</td></tr>

<tr><td>max</td>

<td>1...n</td>

<td>Hard Maximum number of connections that will be

allowed to the backend server. The default for a Hard Maximum

for the number of connections is the number of threads per process in the

active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM

it is controlled by the <directive>ThreadsPerChild</directive>.

Apache will never create more than the Hard Maximum connections

to the backend server.</td></tr>

<tr><td>smax</td>

<td>max</td>

<td>Upto the Soft Maximum

number of connections will be created on demand. Any connections above

<code>smax</code> are subject to a time to live or <code>ttl</code>.

</td></tr>

<tr><td>acquire</td>

<td>-</td>

<td>If set this will be the maximum time to wait for a free

connection in the connection pool. If there are no free connections

in the pool the Apache will return <code>SERVER_BUSY</code> status to

the client.

</td></tr>

<tr><td>disablereuse</td>

<td>Off</td>

<td>This parameter should be used when you want to force mod_proxy

to immediately close a connection to the backend after being used, and

thus, disable its persistant connection and pool for that backend.

This helps in various situations where a firewall between Apache and

the backend server (irregardless of protocol) tends to silently

drop connections. To prevent mod_proxy from reusing the backend connection,

set this property value to <code>On</code>.

</td></tr>

<tr><td>flushpackets</td>

<td>off</td>

<td>Determines whether the proxy module will auto-flush the output

brigade after each "chunk" of data. 'off' means that it will flush

only when needed, 'on' means after each chunk is sent and

'auto' means poll/wait for a period of time and flush if

no input has been received for 'flushwait' milliseconds.

Currently this is in effect only for AJP.

</td></tr>

<tr><td>flushwait</td>

<td>10</td>

<td>The time to wait for additional input, in milliseconds, before

flushing the output brigade if 'flushpackets' is 'auto'.

</td></tr>

<tr><td>keepalive</td>

<td>Off</td>

<td>This parameter should be used when you have a firewall between your

Apache and the backend server, who tend to drop inactive connections.

This flag will tell the Operating System to send <code>KEEP_ALIVE</code>

messages on inactive connections (interval depends on global OS settings,

generally 120ms), and thus prevent the firewall to drop the connection.

To enable keepalive set this property value to <code>On</code>.

</td></tr>

<tr><td>lbset</td>

<td>0</td>

<td>Sets the load balancer cluster set that the worker is a member

of. The load balancer will try all members of a lower numbered

lbset before trying higher numbered ones.

</td></tr>

<tr><td>ping</td>

<td>0</td>

<td>Ping property tells webserver to send a <code>CPING</code>

request on ajp13 connection before forwarding a request.

The parameter is the delay in seconds to wait for the

<code>CPONG</code> reply.

This features has been added to avoid problem with hung and

busy Tomcat's and require ajp13 ping/pong support which has

been implemented on Tomcat 3.3.2+, 4.1.28+ and 5.0.13+.

This will increase the network traffic during the normal operation

which could be an issue, but it will lower the

traffic in case some of the cluster nodes are down or busy.

Currently this has an effect only for AJP.

</td></tr>

<tr><td>redirect</td>

<td>-</td>

<td>Redirection Route of the worker. This value is usually

set dynamically to enable safe removal of the node from

the cluster. If set all requests without session id will be

redirected to the BalancerMember that has route parametar

equal as this value.

</td></tr>

<tr><td>retry</td>

<td>60</td>

<td>Connection pool worker retry timeout in seconds.

If the connection pool worker to the backend server is in the error state,

Apache will not forward any requests to that server until the timeout

expires. This enables to shut down the backend server for maintenance,

and bring it back online later. A value of 0 means always retry workers

in an error state with no timeout.

</td></tr>

<tr><td>route</td>

<td>-</td>

<td>Route of the worker when used inside load balancer.

The route is a value appended to session id.

</td></tr>

<tr><td>status</td>

<td>-</td>

<td>Single letter value defining the initial status of

this worker: 'D' is disabled, 'S' is stopped, 'I' is ignore-errors,

'H' is hot-standby and 'E' is in an error state. Status

can be set (which is the default) by prepending with '+' or

cleared by prepending with '-'.

Thus, a setting of 'S-E' sets this worker to Stopped and

clears the in-error flag.

</td></tr>

<tr><td>timeout</td>

<td><directive>Timeout</directive></td>

<td>Connection timeout in seconds.

If not set the Apache will wait until the free connection

is available. This directive is used for limiting the number

of connections to the backend server together with <code>max</code>

parameter.

</td></tr>

<tr><td>ttl</td>

<td>-</td>

<td>Time To Live for the inactive connections above the

<code>smax</code> connections in seconds. Apache will close all

connections that has not been used inside that time period.

</td></tr>

</table>

<p>If the Proxy directive scheme starts with the

<code>balancer://</code> then a virtual worker that does not really

communicate with the backend server will be created. Instead it is responsible

for the management of several "real" workers. In that case the special set of

parameters can be add to this virtual worker. See <module>mod_proxy_balancer</module>

for more information about how the balancer works.

</p>

<table>

<tr><th>Parameter</th>

<th>Default</th>

<th>Description</th></tr>

<tr><td>lbmethod</td>

<td>byrequests</td>

<td>Balancer load-balance method. Select the load-balancing scheduler

method to use. Either <code>byrequests</code>, to perform weighted

request counting or <code>bytraffic</code>, to perform weighted

traffic byte count balancing. Default is <code>byrequests</code>.

</td></tr>

<tr><td>maxattempts</td>

<td>1</td>

<td>Maximum number of failover attempts before giving up.

</td></tr>

<tr><td>nofailover</td>

<td>Off</td>

<td>If set to <code>On</code> the session will break if the worker is in

error state or disabled. Set this value to On if backend servers do not

support session replication.

</td></tr>

<tr><td>stickysession</td>

<td>-</td>

<td>Balancer sticky session name. The value is usually set to something

like <code>JSESSIONID</code> or <code>PHPSESSIONID</code>,

and it depends on the backend application server that support sessions.

If the backend application server uses different name for cookies

and url encoded id (like servlet containers) use | to to separate them.

The first part is for the cookie the second for the path.

</td></tr>

<tr><td>timeout</td>

<td>0</td>

<td>Balancer timeout in seconds. If set this will be the maximum time

to wait for a free worker. Default is not to wait.

</td></tr>

</table>

<p>A sample balancer setup</p>

<example>

ProxyPass /special-area http://special.example.com/ smax=5 max=10<br />

ProxyPass / balancer://mycluster/ stickysession=JSESSIONID|jsessionid nofailover=On<br />

&lt;Proxy balancer://mycluster&gt;<br />

<indent>

BalancerMember http://1.2.3.4:8009<br />

BalancerMember http://1.2.3.5:8009 smax=10<br />

# Less powerful server, don't send as many requests there<br />

BalancerMember http://1.2.3.6:8009 smax=1 loadfactor=20<br />

</indent>

&lt;/Proxy&gt;

</example>

<p>Setting up a hot-standby, that will only be used if no other

members are available</p>

<example>

ProxyPass / balancer://hotcluster/ <br />

&lt;Proxy balancer://hotcluster&gt;<br />

<indent>

BalancerMember http://1.2.3.4:8009 loadfactor=1<br />

BalancerMember http://1.2.3.5:8009 loadfactor=2<br />

# The below is the hot standby<br />

BalancerMember http://1.2.3.6:8009 status=+H<br />

ProxySet lbmethod=bytraffic

</indent>

&lt;/Proxy&gt;

</example>

<p>Normally, mod_proxy will canonicalise ProxyPassed URLs.

But this may be incompatible with some backends, particularly those

that make use of <var>PATH_INFO</var>. The optional <var>nocanon</var>

keyword suppresses this, and passes the URL path "raw" to the

backend. Note that may affect the security of your backend, as it

removes the normal limited protection against URL-based attacks

provided by the proxy.</p>

<p>The optional <var>interpolate</var> keyword, in combination with

<directive>ProxyPassInterpolateEnv</directive> causes the ProxyPass

to interpolate environment variables, using the syntax

<var>${VARNAME}</var>. Note that many of the standard CGI-derived

environment variables will not exist when this interpolation happens,

so you may still have to resort to <module>mod_rewrite</module>

for complex rules.</p>

<p>When used inside a <directive type="section" module="core"

>Location</directive> section, the first argument is omitted and the local

directory is obtained from the <directive type="section" module="core"

>Location</directive>.</p>

<p>If you require a more flexible reverse-proxy configuration, see the

<directive module="mod_rewrite">RewriteRule</directive> directive with the

<code>[P]</code> flag.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyPassMatch</name>

<description>Maps remote servers into the local server URL-space using regular expressions</description>

<syntax>ProxyPassMatch [<var>regex</var>] !|<var>url</var> [<var>key=value</var>

<var>[key=value</var> ...]]</syntax>

<contextlist><context>server config</context><context>virtual host</context>

<context>directory</context>

</contextlist>

<usage>

<p>This directive is equivalent to <directive module="mod_proxy">ProxyPass</directive>,

but makes use of regular expressions, instead of simple prefix matching. The

supplied regular expression is matched against the <var>url</var>, and if it

matches, the server will substitute any parenthesized matches into the given

string and use it as a new <var>url</var>.</p>

<p>Suppose the local server has address <code>http://example.com/</code>;

then</p>

<example>

ProxyPassMatch ^(/.*\.gif)$ http://backend.example.com$1

</example>

<p>will cause a local request for

<code>http://example.com/mirror/foo/bar.gif</code> to be internally converted

into a proxy request to <code>http://backend.example.com/foo/bar.gif</code>.</p>

<p>The <code>!</code> directive is useful in situations where you don't want

to reverse-proxy a subdirectory.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyPassReverse</name>

<description>Adjusts the URL in HTTP response headers sent from a reverse

proxied server</description>

<syntax>ProxyPassReverse [<var>path</var>] <var>url</var>

[<var>interpolate</var>]</syntax>

<contextlist><context>server config</context><context>virtual host</context>

<context>directory</context>

</contextlist>

<usage>

<p>This directive lets Apache adjust the URL in the <code>Location</code>,

<code>Content-Location</code> and <code>URI</code> headers on HTTP redirect

responses. This is essential when Apache is used as a reverse proxy to avoid

by-passing the reverse proxy because of HTTP redirects on the backend

servers which stay behind the reverse proxy.</p>

<p>Only the HTTP response headers specifically mentioned above

will be rewritten. Apache will not rewrite other response

headers, nor will it rewrite URL references inside HTML pages.

This means that if the proxied content contains absolute URL

references, they will by-pass the proxy. A third-party module

that will look inside the HTML and rewrite URL references is Nick

Kew's <a href="http://apache.webthing.com/mod_proxy_html/"

>mod_proxy_html</a>.</p>

<p><var>path</var> is the name of a local virtual path. <var>url</var> is a

partial URL for the remote server - the same way they are used for the

<directive module="mod_proxy">ProxyPass</directive> directive.</p>

<p>For example, suppose the local server has address

<code>http://example.com/</code>; then</p>

<example>

ProxyPass /mirror/foo/ http://backend.example.com/<br />

ProxyPassReverse /mirror/foo/ http://backend.example.com/<br />

ProxyPassReverseCookieDomain backend.example.com public.example.com<br />

ProxyPassReverseCookiePath / /mirror/foo/

</example>

<p>will not only cause a local request for the

<code>http://example.com/mirror/foo/bar</code> to be internally converted

into a proxy request to <code>http://backend.example.com/bar</code>

(the functionality <code>ProxyPass</code> provides here). It also takes care

of redirects the server <code>backend.example.com</code> sends: when

<code>http://backend.example.com/bar</code> is redirected by him to

<code>http://backend.example.com/quux</code> Apache adjusts this to

<code>http://example.com/mirror/foo/quux</code> before forwarding the HTTP

redirect response to the client. Note that the hostname used for

constructing the URL is chosen in respect to the setting of the <directive

module="core">UseCanonicalName</directive> directive.</p>

<p>Note that this <directive>ProxyPassReverse</directive> directive can

also be used in conjunction with the proxy pass-through feature

(<code>RewriteRule ... [P]</code>) from <module>mod_rewrite</module>

because it doesn't depend on a corresponding <directive module="mod_proxy"

>ProxyPass</directive> directive.</p>

<p>The optional <var>interpolate</var> keyword, used together with

<directive>ProxyPassInterpolateEnv</directive>, enables interpolation

of environment variables specified using the format <var>${VARNAME}</var>.

</p>

<p>When used inside a <directive type="section" module="core"

>Location</directive> section, the first argument is omitted and the local

directory is obtained from the <directive type="section" module="core"

>Location</directive>.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyPassReverseCookieDomain</name>

<description>Adjusts the Domain string in Set-Cookie headers from a reverse-

proxied server</description>

<syntax>ProxyPassReverseCookieDomain <var>internal-domain</var>

<var>public-domain</var> [<var>interpolate</var>]</syntax>

<contextlist><context>server config</context><context>virtual host</context>

<context>directory</context>

</contextlist>

<usage>

<p>Usage is basically similar to

<directive module="mod_proxy">ProxyPassReverse</directive>, but instead of

rewriting headers that are a URL, this rewrites the <code>domain</code>

string in <code>Set-Cookie</code> headers.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyPassReverseCookiePath</name>

<description>Adjusts the Path string in Set-Cookie headers from a reverse-

proxied server</description>

<syntax>ProxyPassReverseCookiePath <var>internal-path</var>

<var>public-path</var> [<var>interpolate</var>]</syntax>

<contextlist><context>server config</context><context>virtual host</context>

<context>directory</context>

</contextlist>

<usage>

<p>Usage is basically similar to

<directive module="mod_proxy">ProxyPassReverse</directive>, but instead of

rewriting headers that are a URL, this rewrites the <code>path</code>

string in <code>Set-Cookie</code> headers.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AllowCONNECT</name>

<description>Ports that are allowed to <code>CONNECT</code> through the

proxy</description>

<syntax>AllowCONNECT <var>port</var> [<var>port</var>] ...</syntax>

<default>AllowCONNECT 443 563</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>The <directive>AllowCONNECT</directive> directive specifies a list

of port numbers to which the proxy <code>CONNECT</code> method may

connect. Today's browsers use this method when a <code>https</code>

connection is requested and proxy tunneling over HTTP is in effect.</p>

<p>By default, only the default https port (<code>443</code>) and the

default snews port (<code>563</code>) are enabled. Use the

<directive>AllowCONNECT</directive> directive to override this default and

allow connections to the listed ports only.</p>

<p>Note that you'll need to have <module>mod_proxy_connect</module> present

in the server in order to get the support for the <code>CONNECT</code> at

all.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyBlock</name>

<description>Words, hosts, or domains that are banned from being

proxied</description>

<syntax>ProxyBlock *|<var>word</var>|<var>host</var>|<var>domain</var>

[<var>word</var>|<var>host</var>|<var>domain</var>] ...</syntax>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>The <directive>ProxyBlock</directive> directive specifies a list of

words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and

FTP document requests to sites whose names contain matched words,

hosts or domains are <em>blocked</em> by the proxy server. The proxy

module will also attempt to determine IP addresses of list items which

may be hostnames during startup, and cache them for match test as

well. That may slow down the startup time of the server.</p>

<example><title>Example</title>

ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu

</example>

<p><code>rocky.wotsamattau.edu</code> would also be matched if referenced by

IP address.</p>

<p>Note that <code>wotsamattau</code> would also be sufficient to match

<code>wotsamattau.edu</code>.</p>

<p>Note also that</p>

<example>

ProxyBlock *

</example>

<p>blocks connections to all sites.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyReceiveBufferSize</name>

<description>Network buffer size for proxied HTTP and FTP

connections</description>

<syntax>ProxyReceiveBufferSize <var>bytes</var></syntax>

<default>ProxyReceiveBufferSize 0</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>The <directive>ProxyReceiveBufferSize</directive> directive specifies an

explicit (TCP/IP) network buffer size for proxied HTTP and FTP connections,

for increased throughput. It has to be greater than <code>512</code> or set

to <code>0</code> to indicate that the system's default buffer size should

be used.</p>

<example><title>Example</title>

ProxyReceiveBufferSize 2048

</example>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyIOBufferSize</name>

<description>Determine size of internal data throughput buffer</description>

<syntax>ProxyIOBufferSize <var>bytes</var></syntax>

<default>ProxyIOBufferSize 8192</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>The <directive>ProxyIOBufferSize</directive> directive adjusts the size

of the internal buffer, which is used as a scratchpad for the data between

input and output. The size must be less or equal <code>65536</code>.</p>

<p>In almost every case there's no reason to change that value.</p>

<p>If used with AJP this directive sets the maximum AJP packet size in

bytes. If you change it from the default, you must also change the

<code>packetSize</code> attribute of your AJP connector on the

Tomcat side! The attribute <code>packetSize</code> is only available

in Tomcat <code>5.5.20+</code> and <code>6.0.2+</code></p>

<p>Normally it is not necessary to change the maximum packet size.

Problems with the default value have been reported when sending

certificates or certificate chains.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyMaxForwards</name>

<description>Maximium number of proxies that a request can be forwarded

through</description>

<syntax>ProxyMaxForwards <var>number</var></syntax>

<default>ProxyMaxForwards -1</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<compatibility>Available in Apache 2.0 and later;

default behaviour changed in 2.2.7/2.3</compatibility>

<usage>

<p>The <directive>ProxyMaxForwards</directive> directive specifies the

maximum number of proxies through which a request may pass, if there's no

<code>Max-Forwards</code> header supplied with the request. This may

be set to prevent infinite proxy loops, or a DoS attack.</p>

<example><title>Example</title>

ProxyMaxForwards 15

</example>

<p>Note that setting <directive>ProxyMaxForwards</directive> is a

violation of the HTTP/1.1 protocol (RFC2616), which forbids a Proxy

setting <code>Max-Forwards</code> if the Client didn't set it.

Earlier Apache versions would always set it. A negative

<directive>ProxyMaxForwards</directive> value, including the

default -1, gives you protocol-compliant behaviour, but may

leave you open to loops.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>NoProxy</name>

<description>Hosts, domains, or networks that will be connected to

directly</description>

<syntax>NoProxy <var>host</var> [<var>host</var>] ...</syntax>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>This directive is only useful for Apache proxy servers within

intranets. The <directive>NoProxy</directive> directive specifies a

list of subnets, IP addresses, hosts and/or domains, separated by

spaces. A request to a host which matches one or more of these is

always served directly, without forwarding to the configured

<directive module="mod_proxy">ProxyRemote</directive> proxy server(s).</p>

<example><title>Example</title>

ProxyRemote * http://firewall.mycompany.com:81<br />

NoProxy .mycompany.com 192.168.112.0/21

</example>

<p>The <var>host</var> arguments to the <directive>NoProxy</directive>

directive are one of the following type list:</p>

<dl>

<!-- ===================== Domain ======================= -->

<dt><var><a name="domain" id="domain">Domain</a></var></dt>

<dd>

<p>A <dfn>Domain</dfn> is a partially qualified DNS domain name, preceded

by a period. It represents a list of hosts which logically belong to the

same DNS domain or zone (<em>i.e.</em>, the suffixes of the hostnames are

all ending in <var>Domain</var>).</p>

<example><title>Examples</title>

.com .apache.org.

</example>

<p>To distinguish <var>Domain</var>s from <var><a href="#hostname"

>Hostname</a></var>s (both syntactically and semantically; a DNS domain can

have a DNS A record, too!), <var>Domain</var>s are always written with a

leading period.</p>

<note><title>Note</title>

<p>Domain name comparisons are done without regard to the case, and

<var>Domain</var>s are always assumed to be anchored in the root of the

DNS tree, therefore two domains <code>.MyDomain.com</code> and

<code>.mydomain.com.</code> (note the trailing period) are considered

equal. Since a domain comparison does not involve a DNS lookup, it is much

more efficient than subnet comparison.</p>

</note></dd>

<!-- ===================== SubNet ======================= -->

<dt><var><a name="subnet" id="subnet">SubNet</a></var></dt>

<dd>

<p>A <dfn>SubNet</dfn> is a partially qualified internet address in

numeric (dotted quad) form, optionally followed by a slash and the netmask,

specified as the number of significant bits in the <var>SubNet</var>. It is

used to represent a subnet of hosts which can be reached over a common

network interface. In the absence of the explicit net mask it is assumed

that omitted (or zero valued) trailing digits specify the mask. (In this

case, the netmask can only be multiples of 8 bits wide.) Examples:</p>

<dl>

<dt><code>192.168</code> or <code>192.168.0.0</code></dt>

<dd>the subnet 192.168.0.0 with an implied netmask of 16 valid bits

(sometimes used in the netmask form <code>255.255.0.0</code>)</dd>

<dt><code>192.168.112.0/21</code></dt>

<dd>the subnet <code>192.168.112.0/21</code> with a netmask of 21

valid bits (also used in the form <code>255.255.248.0</code>)</dd>

</dl>

<p>As a degenerate case, a <em>SubNet</em> with 32 valid bits is the

equivalent to an <var><a href="#ipadr">IPAddr</a></var>, while a <var>SubNet</var> with zero

valid bits (<em>e.g.</em>, 0.0.0.0/0) is the same as the constant

<var>_Default_</var>, matching any IP address.</p></dd>

<!-- ===================== IPAddr ======================= -->

<dt><var><a name="ipaddr" id="ipaddr">IPAddr</a></var></dt>

<dd>

<p>A <dfn>IPAddr</dfn> represents a fully qualified internet address in

numeric (dotted quad) form. Usually, this address represents a host, but

there need not necessarily be a DNS domain name connected with the

address.</p>

<example><title>Example</title>

192.168.123.7

</example>

<note><title>Note</title>

<p>An <var>IPAddr</var> does not need to be resolved by the DNS system, so

it can result in more effective apache performance.</p>

</note></dd>

<!-- ===================== Hostname ======================= -->

<dt><var><a name="hostname" id="hostname">Hostname</a></var></dt>

<dd>

<p>A <dfn>Hostname</dfn> is a fully qualified DNS domain name which can

be resolved to one or more <var><a href="#ipaddr">IPAddrs</a></var> via the

DNS domain name service. It represents a logical host (in contrast to

<var><a href="#domain">Domain</a></var>s, see above) and must be resolvable

to at least one <var><a href="#ipaddr">IPAddr</a></var> (or often to a list

of hosts with different <var><a href="#ipaddr">IPAddr</a></var>s).</p>

<example><title>Examples</title>

prep.ai.mit.edu<br />

www.apache.org

</example>

<note><title>Note</title>

<p>In many situations, it is more effective to specify an <var><a

href="#ipaddr">IPAddr</a></var> in place of a <var>Hostname</var> since a

DNS lookup can be avoided. Name resolution in Apache can take a remarkable

deal of time when the connection to the name server uses a slow PPP

link.</p>

<p><var>Hostname</var> comparisons are done without regard to the case,

and <var>Hostname</var>s are always assumed to be anchored in the root

of the DNS tree, therefore two hosts <code>WWW.MyDomain.com</code>

and <code>www.mydomain.com.</code> (note the trailing period) are

considered equal.</p>

</note></dd>

</dl>

</usage>

<seealso><a href="/dns-caveats.html">DNS Issues</a></seealso>

</directivesynopsis>

<directivesynopsis>

<name>ProxyTimeout</name>

<description>Network timeout for proxied requests</description>

<syntax>ProxyTimeout <var>seconds</var></syntax>

<default>ProxyTimeout 300</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<compatibility>Available in Apache 2.0.31 and later</compatibility>

<usage>

<p>This directive allows a user to specifiy a timeout on proxy requests.

This is useful when you have a slow/buggy appserver which hangs, and you

would rather just return a timeout and fail gracefully instead of waiting

however long it takes the server to return.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyDomain</name>

<description>Default domain name for proxied requests</description>

<syntax>ProxyDomain <var>Domain</var></syntax>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>This directive is only useful for Apache proxy servers within

intranets. The <directive>ProxyDomain</directive> directive specifies

the default domain which the apache proxy server will belong to. If a

request to a host without a domain name is encountered, a redirection

response to the same host with the configured <var>Domain</var> appended

will be generated.</p>

<example><title>Example</title>

ProxyRemote * http://firewall.mycompany.com:81<br />

NoProxy .mycompany.com 192.168.112.0/21<br />

ProxyDomain .mycompany.com

</example>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyVia</name>

<description>Information provided in the <code>Via</code> HTTP response

header for proxied requests</description>

<syntax>ProxyVia On|Off|Full|Block</syntax>

<default>ProxyVia Off</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<usage>

<p>This directive controls the use of the <code>Via:</code> HTTP

header by the proxy. Its intended use is to control the flow of

proxy requests along a chain of proxy servers. See <a

href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a> (HTTP/1.1), section

14.45 for an explanation of <code>Via:</code> header lines.</p>

<ul>

<li>If set to <code>Off</code>, which is the default, no special processing

is performed. If a request or reply contains a <code>Via:</code> header,

it is passed through unchanged.</li>

<li>If set to <code>On</code>, each request and reply will get a

<code>Via:</code> header line added for the current host.</li>

<li>If set to <code>Full</code>, each generated <code>Via:</code> header

line will additionally have the Apache server version shown as a

<code>Via:</code> comment field.</li>

<li>If set to <code>Block</code>, every proxy request will have all its

<code>Via:</code> header lines removed. No new <code>Via:</code> header will

be generated.</li>

</ul>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyErrorOverride</name>

<description>Override error pages for proxied content</description>

<syntax>ProxyErrorOverride On|Off</syntax>

<default>ProxyErrorOverride Off</default>

<contextlist><context>server config</context><context>virtual host</context>

</contextlist>

<compatibility>Available in version 2.0 and later</compatibility>

<usage>

<p>This directive is useful for reverse-proxy setups, where you want to

have a common look and feel on the error pages seen by the end user.

This also allows for included files (via

<module>mod_include</module>'s SSI) to get

the error code and act accordingly (default behavior would display

the error page of the proxied server, turning this on shows the SSI

Error message).</p>

<p>This directive does not affect the processing of informational (1xx),

normal success (2xx), or redirect (3xx) responses.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>ProxyPassInterpolateEnv</name>

<description>Enable Environment Variable interpolation in Reverse Proxy configurations</description>

<syntax>ProxyPassInterpolateEnv On|Off</syntax>

<default>ProxyPassInterpolateEnv Off</default>

<contextlist><context>server config</context>

<context>virtual host</context>

<context>directory</context>

</contextlist>

<compatibility>Available in trunk only</compatibility>

<usage>

<p>This directive, together with the <var>interpolate</var> argument to

<directive>ProxyPass</directive>, <directive>ProxyPassReverse</directive>,

<directive>ProxyPassReverseCookieDomain</directive> and

<directive>ProxyPassReverseCookiePath</directive>

enables reverse proxies to be dynamically

configured using environment variables, which may be set by

another module such as <module>mod_rewrite</module>.