| [66] | 1 | <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat 6.0 - Proxy Support HOW-TO</title><meta value="Craig R. McClanahan" name="author"><meta value="craigmcc@apache.org" name="email"></head><body vlink="#525D76" alink="#525D76" link="#525D76" text="#000000" bgcolor="#ffffff"><table cellspacing="0" width="100%" border="0"><!--PAGE HEADER--><tr><td><!--PROJECT LOGO--><a href="http://tomcat.apache.org/"><img border="0" alt=" |
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| 2 | The Apache Tomcat Servlet/JSP Container |
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| 3 | " align="right" src="./../images/tomcat.gif"></a></td><td><font face="arial,helvetica,sanserif"><h1>Apache Tomcat 6.0</h1></font></td><td><!--APACHE LOGO--><a href="http://www.apache.org/"><img border="0" alt="Apache Logo" align="right" src="./../images/asf-logo.gif"></a></td></tr></table><table cellspacing="4" width="100%" border="0"><!--HEADER SEPARATOR--><tr><td colspan="2"><hr size="1" noshade></td></tr><tr><!--RIGHT SIDE MAIN BODY--><td align="left" valign="top" width="80%"><table cellspacing="4" width="100%" border="0"><tr><td valign="top" align="left"><h1>Apache Tomcat 6.0</h1><h2>Proxy Support HOW-TO</h2></td><td nowrap="true" valign="top" align="right"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> |
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| 4 | |
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| 5 | <p>Using standard configurations of Tomcat, web applications can ask for |
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| 6 | the server name and port number to which the request was directed for |
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| 7 | processing. When Tomcat is running standalone with the |
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| 8 | <a href="../config/coyote.html">Coyote HTTP/1.1 Connector</a>, it will generally |
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| 9 | report the server name specified in the request, and the port number on |
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| 10 | which the <strong>Connector</strong> is listening. The servlet API |
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| 11 | calls of interest, for this purpose, are:</p> |
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| 12 | <ul> |
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| 13 | <li><code>ServletRequest.getServerName()</code>: Returns the host name of the server to which the request was sent.</li> |
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| 14 | <li><code>ServletRequest.getServerPort()</code>: Returns the host name of the server to which the request was sent.</li> |
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| 15 | <li><code>ServletRequest.getLocalName()</code>: Returns the host name of the Internet Protocol (IP) interface on which the request was received.</li> |
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| 16 | <li><code>ServletRequest.getLocalPort()</code>: Returns the Internet Protocol (IP) port number of the interface on which the request was received.</li> |
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| 17 | </ul> |
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| 18 | |
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| 19 | <p>When you are running behind a proxy server (or a web server that is |
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| 20 | configured to behave like a proxy server), you will sometimes prefer to |
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| 21 | manage the values returned by these calls. In particular, you will |
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| 22 | generally want the port number to reflect that specified in the original |
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| 23 | request, not the one on which the <strong>Connector</strong> itself is |
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| 24 | listening. You can use the <code>proxyName</code> and <code>proxyPort</code> |
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| 25 | attributes on the <code><Connector></code> element to configure |
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| 26 | these values.</p> |
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| 27 | |
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| 28 | <p>Proxy support can take many forms. The following sections describe |
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| 29 | proxy configurations for several common cases.</p> |
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| 30 | |
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| 31 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Apache 1.3 Proxy Support"><strong>Apache 1.3 Proxy Support</strong></a></font></td></tr><tr><td><blockquote> |
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| 32 | |
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| 33 | <p>Apache 1.3 supports an optional module (<code>mod_proxy</code>) that |
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| 34 | configures the web server to act as a proxy server. This can be used to |
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| 35 | forward requests for a particular web application to a Tomcat 6 instance, |
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| 36 | without having to configure a web connector such as <code>mod_jk</code>. |
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| 37 | To accomplish this, you need to perform the following tasks:</p> |
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| 38 | <ol> |
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| 39 | <li>Configure your copy of Apache so that it includes the |
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| 40 | <code>mod_proxy</code> module. If you are building from source, |
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| 41 | the easiest way to do this is to include the |
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| 42 | <code>--enable-module=proxy</code> directive on the |
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| 43 | <code>./configure</code> command line.</li> |
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| 44 | <li>If not already added for you, make sure that you are loading the |
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| 45 | <code>mod_proxy</code> module at Apache startup time, by using the |
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| 46 | following directives in your <code>httpd.conf</code> file: |
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| 47 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre> |
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| 48 | LoadModule proxy_module {path-to-modules}/mod_proxy.so |
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| 49 | AddModule mod_proxy.c |
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| 50 | </pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr></table></div></li> |
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| 51 | <li>Include two directives in your <code>httpd.conf</code> file for |
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| 52 | each web application that you wish to forward to Tomcat 6. For |
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| 53 | example, to forward an application at context path <code>/myapp</code>: |
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| 54 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre> |
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| 55 | ProxyPass /myapp http://localhost:8081/myapp |
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| 56 | ProxyPassReverse /myapp http://localhost:8081/myapp |
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| 57 | </pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr></table></div> |
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| 58 | which tells Apache to forward URLs of the form |
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| 59 | <code>http://localhost/myapp/*</code> to the Tomcat 6 connector |
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| 60 | listening on port 8081.</li> |
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| 61 | <li>Configure your copy of Tomcat 6 to include a special |
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| 62 | <code><Connector></code> element, with appropriate |
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| 63 | proxy settings, for example: |
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| 64 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre> |
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| 65 | <Connector port="8081" ... |
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| 66 | proxyName="www.mycompany.com" |
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| 67 | proxyPort="80"/> |
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| 68 | </pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="./../images/void.gif"></td></tr></table></div> |
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| 69 | which will cause servlets inside this web application to think that |
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| 70 | all proxied requests were directed to <code>www.mycompany.com</code> |
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| 71 | on port 80.</li> |
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| 72 | <li>It is legal to omit the <code>proxyName</code> attribute from the |
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| 73 | <code><Connector></code> element. If you do so, the value |
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| 74 | returned by <code>request.getServerName()</code> will by the host |
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| 75 | name on which Tomcat is running. In the example above, it would be |
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| 76 | <code>localhost</code>.</li> |
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| 77 | <li>If you also have a <code><Connector></code> listening on port |
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| 78 | 8080 (nested within the same <a href="../config/service.html">Service</a> |
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| 79 | element), the requests to either port will share the same set of |
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| 80 | virtual hosts and web applications.</li> |
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| 81 | <li>You might wish to use the IP filtering features of your operating |
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| 82 | system to restrict connections to port 8081 (in this example) to |
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| 83 | be allowed <strong>only</strong> from the server that is running |
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| 84 | Apache.</li> |
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| 85 | <li>Alternatively, you can set up a series of web applications that are |
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| 86 | only available via proxying, as follows: |
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| 87 | <ul> |
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| 88 | <li>Configure another <code><Service></code> that contains |
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| 89 | only a <code><Connector></code> for the proxy port.</li> |
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| 90 | <li>Configure appropriate <a href="../config/engine.html">Engine</a>, |
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| 91 | <a href="../config/host.html">Host</a>, and |
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| 92 | <a href="../config/context.html">Context</a> elements for the virtual hosts |
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| 93 | and web applications accessible via proxying.</li> |
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| 94 | <li>Optionally, protect port 8081 with IP filters as described |
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| 95 | earlier.</li> |
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| 96 | </ul></li> |
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| 97 | <li>When requests are proxied by Apache, the web server will be recording |
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| 98 | these requests in its access log. Therefore, you will generally want to |
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| 99 | disable any access logging performed by Tomcat itself.</li> |
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| 100 | </ol> |
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| 101 | |
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| 102 | <p>When requests are proxied in this manner, <strong>all</strong> requests |
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| 103 | for the configured web applications will be processed by Tomcat (including |
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| 104 | requests for static content). You can improve performance by using the |
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| 105 | <code>mod_jk</code> web connector instead of <code>mod_proxy</code>. |
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| 106 | <code>mod_jk</code> can be configured so that the web server serves static |
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| 107 | content that is not processed by filters or security constraints defined |
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| 108 | within the web application's deployment descriptor |
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| 109 | (<code>/WEB-INF/web.xml</code>).</p> |
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| 110 | |
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| 111 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Apache 2.0 Proxy Support"><strong>Apache 2.0 Proxy Support</strong></a></font></td></tr><tr><td><blockquote> |
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| 112 | The same instructions hold true as for 1.3. (Except in Apache 2.0, |
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| 113 | you may omit <code>AddModule mod_proxy.c</code>) |
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| 114 | </blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr size="1" noshade></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font size="-1" color="#525D76"><em> |
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| 115 | Copyright © 1999-2008, Apache Software Foundation |
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| 116 | </em></font></div></td></tr></table></body></html> |
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