Apache Module mod_proxy_http

Available Languages: en | + fr

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Description:	HTTP support module for +`mod_proxy`
Status:	Extension
Module Identifier:	proxy_http_module
Source File:	mod_proxy_http.c

Summary

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This module requires the service of mod_proxy. It provides the features used for + proxying HTTP and HTTPS requests. mod_proxy_http + supports HTTP/0.9, HTTP/1.0 and HTTP/1.1. It does not + provide any caching abilities. If you want to set up a caching + proxy, you might want to use the additional service of the + mod_cache module.

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Thus, in order to get the ability of handling HTTP proxy requests, + mod_proxy and mod_proxy_http + have to be present in the server.

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Warning

Do not enable proxying until you have secured your server. Open proxy + servers are dangerous both to your network and to the Internet at + large.

Directives

This module provides no + directives.

Bugfix checklist

Environment Variables

In addition to the configuration directives that control the + behaviour of mod_proxy, there are a number of + environment variables that control the HTTP protocol + provider. Environment variables below that don't specify specific values + are enabled when set to any value.

proxy-sendextracrlf: 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.
force-proxy-request-1.0: Forces the proxy to send requests to the backend as HTTP/1.0 + and disables HTTP/1.1 features.
proxy-nokeepalive: Forces the proxy to close the backend connection after + each request.
proxy-chain-auth: If the proxy requires authentication, it will read and + consume the proxy authentication credentials sent by the client. + With proxy-chain-auth it will also 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. Security Warning: + Do not set this unless you know you need it, as it forwards + sensitive information!
proxy-sendcl: HTTP/1.0 required all HTTP requests that include a body + (e.g. POST requests) to include a Content-Length + 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.
proxy-sendchunks or proxy-sendchunked: This is the opposite of proxy-sendcl. 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.
proxy-interim-response: This variable takes values RFC (the default) or + Suppress. 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 + proxy-interim-response RFC to be fully protocol + compliant, or proxy-interim-response Suppress + to suppress interim responses.
proxy-initial-not-pooled: 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. +

Request notes

mod_proxy_http creates the following request notes for + logging using the %{VARNAME}n format in + LogFormat or + ErrorLogFormat: +

proxy-source-port: The local port used for the connection to the backend server.
proxy-status: The HTTP status received from the backend server.