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| <modulesynopsis metafile="mod_proxy_http.xml.meta"> |
| |
| <name>mod_proxy_http</name> |
| <description>HTTP support module for |
| <module>mod_proxy</module></description> |
| <status>Extension</status> |
| <sourcefile>mod_proxy_http.c</sourcefile> |
| <identifier>proxy_http_module</identifier> |
| |
| <summary> |
| <p>This module <em>requires</em> the service of <module |
| >mod_proxy</module>. It provides the features used for |
| proxying HTTP and HTTPS requests. <module>mod_proxy_http</module> |
| supports HTTP/0.9, HTTP/1.0 and HTTP/1.1. It does <em>not</em> |
| provide any caching abilities. If you want to set up a caching |
| proxy, you might want to use the additional service of the |
| <module>mod_cache</module> module.</p> |
| |
| <p>Thus, in order to get the ability of handling HTTP proxy requests, |
| <module>mod_proxy</module> and <module>mod_proxy_http</module> |
| have to be present in the server.</p> |
| |
| <note type="warning"><title>Warning</title> |
| <p>Do not enable proxying until you have <a |
| href="mod_proxy.html#access">secured your server</a>. Open proxy |
| servers are dangerous both to your network and to the Internet at |
| large.</p> |
| </note> |
| </summary> |
| <seealso><module>mod_proxy</module></seealso> |
| <seealso><module>mod_proxy_connect</module></seealso> |
| |
| <section id="env"><title>Environment Variables</title> |
| <p>In addition to the configuration directives that control the |
| behaviour of <module>mod_proxy</module>, there are a number of |
| <dfn>environment variables</dfn> that control the HTTP protocol |
| provider. Environment variables below that don't specify specific values |
| are enabled when set to any value.</p> |
| <dl> |
| <dt>proxy-sendextracrlf</dt> |
| <dd>Causes proxy to send an extra CR-LF newline on the end of a |
| request. This is a workaround for a bug in some browsers.</dd> |
| <dt>force-proxy-request-1.0</dt> |
| <dd>Forces the proxy to send requests to the backend as HTTP/1.0 |
| and disables HTTP/1.1 features.</dd> |
| <dt>proxy-nokeepalive</dt> |
| <dd>Forces the proxy to close the backend connection after |
| each request.</dd> |
| <dt>proxy-chain-auth</dt> |
| <dd>If the proxy requires authentication, it will read and |
| consume the proxy authentication credentials sent by the client. |
| With <var>proxy-chain-auth</var> it will <em>also</em> forward |
| the credentials to the next proxy in the chain. This may |
| be necessary if you have a chain of proxies that share |
| authentication information. <strong>Security Warning:</strong> |
| Do not set this unless you know you need it, as it forwards |
| sensitive information!</dd> |
| <dt>proxy-sendcl</dt> |
| <dd>HTTP/1.0 required all HTTP requests that include a body |
| (e.g. POST requests) to include a <var>Content-Length</var> |
| header. This environment variable forces the Apache proxy to |
| send this header to the backend server, regardless of what the |
| Client sent to the proxy. It ensures compatibility when |
| proxying for an HTTP/1.0 or unknown backend. However, it |
| may require the entire request to be buffered by the proxy, |
| so it becomes very inefficient for large requests.</dd> |
| <dt>proxy-sendchunks or proxy-sendchunked</dt> |
| <dd>This is the opposite of <var>proxy-sendcl</var>. It allows |
| request bodies to be sent to the backend using chunked transfer |
| encoding. This allows the request to be efficiently streamed, |
| but requires that the backend server supports HTTP/1.1.</dd> |
| <dt>proxy-interim-response</dt> |
| <dd>This variable takes values <code>RFC</code> (the default) or |
| <code>Suppress</code>. Earlier httpd versions would suppress |
| HTTP interim (1xx) responses sent from the backend. This is |
| technically a violation of the HTTP protocol. In practice, |
| if a backend sends an interim response, it may itself be |
| extending the protocol in a manner we know nothing about, |
| or just broken. So this is now configurable: set |
| <code>proxy-interim-response RFC</code> to be fully protocol |
| compliant, or <code>proxy-interim-response Suppress</code> |
| to suppress interim responses.</dd> |
| <dt>proxy-initial-not-pooled</dt> |
| <dd>If this variable is set, no pooled connection will be reused |
| if the client request is the initial request on the frontend connection. This avoids |
| the "proxy: error reading status line from remote server" error message |
| caused by the race condition that the backend server closed the |
| pooled connection after the connection check by the proxy and |
| before data sent by the proxy reached the backend. It has to be |
| kept in mind that setting this variable downgrades performance, |
| especially with HTTP/1.0 clients. |
| </dd> |
| </dl> |
| </section> |
| |
| <section id="notes"><title>Request notes</title> |
| <p><module>mod_proxy_http</module> creates the following request notes for |
| logging using the <code>%{VARNAME}n</code> format in |
| <directive module="mod_log_config">LogFormat</directive> or |
| <directive module="core">ErrorLogFormat</directive>: |
| </p> |
| <dl> |
| <dt>proxy-source-port</dt> |
| <dd>The local port used for the connection to the backend server.</dd> |
| <dt>proxy-status</dt> |
| <dd>The HTTP status received from the backend server.</dd> |
| </dl> |
| </section> |
| |
| </modulesynopsis> |