📄 mass.html.en
字号:
<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!-- XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX This file is generated from xml source: DO NOT EDIT XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --><title>Dynamically Configured Mass Virtual Hosting - Apache HTTP Server</title><link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /><link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /><link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link href="../images/favicon.ico" rel="shortcut icon" /></head><body id="manual-page"><div id="page-header"><p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p><p class="apache">Apache HTTP Server Version 2.0</p><img alt="" src="../images/feather.gif" /></div><div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div><div id="path"><a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.0</a> > <a href="./">Virtual Hosts</a></div><div id="page-content"><div id="preamble"><h1>Dynamically Configured Mass Virtual Hosting</h1><div class="toplang"><p><span>Available Languages: </span><a href="../en/vhosts/mass.html" title="English"> en </a> |<a href="../ko/vhosts/mass.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p></div> <p>This document describes how to efficiently serve an arbitrary number of virtual hosts with the Apache httpd webserver. </p></div><div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#motivation">Motivation</a></li><li><img alt="" src="../images/down.gif" /> <a href="#overview">Overview</a></li><li><img alt="" src="../images/down.gif" /> <a href="#simple">Simple Dynamic Virtual Hosts</a></li><li><img alt="" src="../images/down.gif" /> <a href="#homepages">A Virtually Hosted Homepages System</a></li><li><img alt="" src="../images/down.gif" /> <a href="#combinations">Using Multiple Virtual Hosting Systems on the Same Server</a></li><li><img alt="" src="../images/down.gif" /> <a href="#ipbased">More Efficient IP-Based Virtual Hosting</a></li><li><img alt="" src="../images/down.gif" /> <a href="#simple.rewrite">Simple Dynamic Virtual Hosts Using <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code></a></li><li><img alt="" src="../images/down.gif" /> <a href="#homepages.rewrite">A Homepages System Using <code>mod_rewrite</code></a></li><li><img alt="" src="../images/down.gif" /> <a href="#xtra-conf">Using a Separate Virtual Host Configuration File</a></li></ul></div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div><div class="section"><h2><a name="motivation" id="motivation">Motivation</a></h2> <p>The techniques described here are of interest if your <code>httpd.conf</code> contains many <code><VirtualHost></code> sections that are substantially the same, for example:</p><div class="example"><p><code>NameVirtualHost 111.22.33.44<br /><VirtualHost 111.22.33.44><br /><span class="indent"> ServerName www.customer-1.com<br /> DocumentRoot /www/hosts/www.customer-1.com/docs<br /> ScriptAlias /cgi-bin/ /www/hosts/www.customer-1.com/cgi-bin<br /></span></VirtualHost><br /><VirtualHost 111.22.33.44><br /><span class="indent"> ServerName www.customer-2.com<br /> DocumentRoot /www/hosts/www.customer-2.com/docs<br /> ScriptAlias /cgi-bin/ /www/hosts/www.customer-2.com/cgi-bin<br /></span></VirtualHost><br /># blah blah blah<br /><VirtualHost 111.22.33.44><br /><span class="indent"> ServerName www.customer-N.com<br /> DocumentRoot /www/hosts/www.customer-N.com/docs<br /> ScriptAlias /cgi-bin/ /www/hosts/www.customer-N.com/cgi-bin<br /></span></VirtualHost></code></p></div> <p>The basic idea is to replace all of the static <code><VirtualHost></code> configurations with a mechanism that works them out dynamically. This has a number of advantages:</p> <ol> <li>Your configuration file is smaller, so Apache starts more quickly and uses less memory.</li> <li>Adding virtual hosts is simply a matter of creating the appropriate directories in the filesystem and entries in the DNS - you don't need to reconfigure or restart Apache.</li> </ol> <p>The main disadvantage is that you cannot have a different log file for each virtual host; however, if you have many virtual hosts, doing this can be a bad idea anyway, because of the number of file descriptors needed. It is better to log to a pipe or a fifo, and arrange for the process at the other end to distribute the logs to the customers. (This can also be used to accumulate statistics, etc.).</p></div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div><div class="section"><h2><a name="overview" id="overview">Overview</a></h2> <p>A virtual host is defined by two pieces of information: its IP address, and the contents of the <code>Host:</code> header in the HTTP request. The dynamic mass virtual hosting technique used here is based on automatically inserting this information into the pathname of the file that is used to satisfy the request. This can be most easily done by using <code class="module"><a href="../mod/mod_vhost_alias.html">mod_vhost_alias</a></code> with Apache 2.0. Alternatively, <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> can be used. Both of these modules are disabled by default; you must enable one of them when configuring and building Apache if you want to use this technique.</p> <p>A couple of things need to be `faked' to make the dynamic virtual host look like a normal one. The most important is the server name, which is used by Apache to generate self-referential URLs etc. It is configured with the <code>ServerName</code> directive, and it is available to CGIs via the <code>SERVER_NAME</code> environment variable. The actual value used at run time is controlled by the <code class="directive"><a href="../mod/core.html#usecanonicalname">UseCanonicalName</a></code> setting. With <code>UseCanonicalName Off</code>, the server name is taken from the contents of the <code>Host:</code> header in the request. With <code>UseCanonicalName DNS</code>, it is taken from a reverse DNS lookup of the virtual host's IP address. The former setting is used for name-based dynamic virtual hosting, and the latter is used for IP-based hosting. If Apache cannot work out the server name because there is no <code>Host:</code> header, or the DNS lookup fails, then the value configured with <code>ServerName</code> is used instead.</p> <p>The other thing to `fake' is the document root (configured with <code>DocumentRoot</code> and available to CGIs via the <code>DOCUMENT_ROOT</code> environment variable). In a normal configuration, this is used by the core module when mapping URIs to filenames, but when the server is configured to do dynamic virtual hosting, that job must be taken over by another module (either <code>mod_vhost_alias</code> or <code>mod_rewrite</code>), which has a different way of doing the mapping. Neither of these modules is responsible for setting the <code>DOCUMENT_ROOT</code> environment variable so if any CGIs or SSI documents make use of it, they will get a misleading value.</p></div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div><div class="section"><h2><a name="simple" id="simple">Simple Dynamic Virtual Hosts</a></h2> <p>This extract from <code>httpd.conf</code> implements the virtual host arrangement outlined in the <a href="#motivation">Motivation</a> section above, but in a generic fashion using <code>mod_vhost_alias</code>.</p><div class="example"><p><code># get the server name from the Host: header<br />UseCanonicalName Off<br /><br /># this log format can be split per-virtual-host based on the first field<br />LogFormat "%V %h %l %u %t \"%r\" %s %b" vcommon<br />CustomLog logs/access_log vcommon<br /><br /># include the server name in the filenames used to satisfy requests<br />VirtualDocumentRoot /www/hosts/%0/docs<br />VirtualScriptAlias /www/hosts/%0/cgi-bin</code></p></div> <p>This configuration can be changed into an IP-based virtual hosting solution by just turning <code>UseCanonicalName Off</code> into <code>UseCanonicalName DNS</code>. The server name that is inserted into the filename is then derived from the IP address of the virtual host.</p></div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div><div class="section"><h2><a name="homepages" id="homepages">A Virtually Hosted Homepages System</a></h2> <p>This is an adjustment of the above system, tailored for an ISP's homepages server. Using a slightly more complicated configuration, we can select substrings of the server name to use in the filename so that, for example, the documents for <code>www.user.isp.com</code> are found in <code>/home/user/</code>. It uses a single <code>cgi-bin</code> directory instead of one per virtual host.</p><div class="example"><p><code># all the preliminary stuff is the same as above, then<br /><br /># include part of the server name in the filenames<br />VirtualDocumentRoot /www/hosts/%2/docs<br /><br /># single cgi-bin directory<br />ScriptAlias /cgi-bin/ /www/std-cgi/<br /></code></p></div> <p>There are examples of more complicated <code>VirtualDocumentRoot</code> settings in the <code class="module"><a href="../mod/mod_vhost_alias.html">mod_vhost_alias</a></code> documentation.</p></div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div><div class="section"><h2><a name="combinations" id="combinations">Using Multiple Virtual Hosting Systems on the Same Server</a></h2> <p>With more complicated setups, you can use Apache's normal <code><VirtualHost></code> directives to control the scope of the various virtual hosting configurations. For example, you could have one IP address for general customers' homepages, and another for commercial customers, with the following setup. This can, of course, be combined with conventional⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -