<?xml version="1.0"?>
<!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd">
<?xml-stylesheet type="text/xsl" href="../style/manual.en.xsl"?>
<!-- $LastChangedRevision$ -->

<!--
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
 this work for additional information regarding copyright ownership.
 The ASF licenses this file to You under the Apache License, Version 2.0
 (the "License"); you may not use this file except in compliance with
 the License.  You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
-->

<modulesynopsis metafile="mod_proxy_http2.xml.meta">

<name>mod_proxy_http2</name>
<description>HTTP/2 support module for
<module>mod_proxy</module></description>
<status>Extension</status>
<sourcefile>mod_proxy_http2.c</sourcefile>
<identifier>proxy_http2_module</identifier>

<summary>
    <p><module>mod_proxy_http2</module>
    supports HTTP/2 only, it does <em>not</em>
    provide any downgrades to HTTP/1.1. This means that the backend
    needs to support HTTP/2 because HTTP/1.1 will not be used instead.</p>

    <p>This module <em>requires</em> the service of <module
    >mod_proxy</module>, so in order to get the ability of
    handling HTTP/2 proxy requests,
    <module>mod_proxy</module> and <module>mod_proxy_http2</module>
    need to be both loaded by the server.</p>

    <p><module>mod_proxy_http2</module> works with incoming fronted requests
    using HTTP/1.1 or HTTP/2. In both cases, requests proxied
    to the same backend are sent over a single TCP connection
    whenever possible (namely when the connection can be re-used).</p>

    <p>Caveat: there will be no attemp to consolidate multiple HTTP/1.1 
    frontend requests (configured to be proxied to the same backend)
    into HTTP/2 streams belonging to the same HTTP/2 request.
    Each HTTP/1.1 frontend request will be proxied to the backend using
    a separate HTTP/2 request (trying to re-use the same TCP connection
    if possible).</p>

    <p>This module relies on <a href="http://nghttp2.org/">libnghttp2</a>
    to provide the core http/2 engine.</p>

    <note type="warning"><title>Warning</title>
       <p>This module is experimental. Its behaviors, directives, and 
       defaults are subject to more change from release to 
       release relative to other standard modules. Users are encouraged to 
       consult the "CHANGES" file for potential updates.</p>
    </note>

    <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_http2</module></seealso>
<seealso><module>mod_proxy</module></seealso>
<seealso><module>mod_proxy_connect</module></seealso>

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

    <p>The examples below demonstrate how to configure HTTP/2 for
    backend connections for a reverse proxy. </p>

    <example><title>HTTP/2 (TLS)</title>
    <highlight language="config">
ProxyPass "/app" "h2://app.example.com"
ProxyPassReverse "/app" "https://app.example.com"
    </highlight>
    </example>

    <example><title>HTTP/2 (cleartext)</title>
    <highlight language="config">
ProxyPass "/app" "h2c://app.example.com"
ProxyPassReverse "/app" "http://app.example.com"
    </highlight>
    </example>

    <note>
      <p>The schemes to configure above in
      <directive>ProxyPassReverse</directive> for reverse proxying
      <code>h2</code> (or <code>h2c</code>) protocols are the usual
      <code>https</code> (resp. <code>http</code>) as expected/used by
      the user agent.</p>
    </note>
    </section> <!-- /examples -->

<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/2 status received from the backend server.</dd>
    </dl>
</section>

</modulesynopsis>
