| # Apache Tomcat 7 Version 7.0.42, Jul 2 2013 |

Links Docs Home FAQ User Comments User Guide 1) Introduction 2) Setup 3) First webapp 4) Deployer 5) Manager 6) Realms and AAA 7) Security Manager 8) JNDI Resources 9) JDBC DataSources 10) Classloading 11) JSPs 12) SSL 13) SSI 14) CGI 15) Proxy Support 16) MBean Descriptor 17) Default Servlet 18) Clustering 19) Load Balancer 20) Connectors 21) Monitoring and Management 22) Logging 23) APR/Native 24) Virtual Hosting 25) Advanced IO 26) Additional Components 27) Mavenized 28) Security Considerations 29) Windows Service 30) Windows Authentication 31) Tomcat's JDBC Pool 32) WebSocket Reference Release Notes Configuration Tomcat Javadocs Servlet Javadocs JSP 2.2 Javadocs EL 2.2 Javadocs JK 1.2 Documentation Apache Tomcat Development Building Changelog Status Developers Architecture Functional Specs. Tribes | # Proxy Support HOW-TO
Table of Contents
Introduction Apache 1.3 Proxy Support Apache 2.0 Proxy Support
Introduction
Using standard configurations of Tomcat, web applications can ask for the server name and port number to which the request was directed for processing. When Tomcat is running standalone with the Coyote HTTP/1.1 Connector, it will generally report the server name specified in the request, and the port number on which the Connector is listening. The servlet API calls of interest, for this purpose, are: `ServletRequest.getServerName()`: Returns the host name of the server to which the request was sent. `ServletRequest.getServerPort()`: Returns the host name of the server to which the request was sent. `ServletRequest.getLocalName()`: Returns the host name of the Internet Protocol (IP) interface on which the request was received. `ServletRequest.getLocalPort()`: Returns the Internet Protocol (IP) port number of the interface on which the request was received. When you are running behind a proxy server (or a web server that is configured to behave like a proxy server), you will sometimes prefer to manage the values returned by these calls. In particular, you will generally want the port number to reflect that specified in the original request, not the one on which the Connector itself is listening. You can use the `proxyName` and `proxyPort` attributes on the `<Connector>` element to configure these values. Proxy support can take many forms. The following sections describe proxy configurations for several common cases.
Apache 1.3 Proxy Support
> 2. Apache 1.3 supports an optional module (`mod_proxy`) that configures the web server to act as a proxy server. This can be used to forward requests for a particular web application to a Tomcat instance, without having to configure a web connector such as `mod_jk`. To accomplish this, you need to perform the following tasks: Configure your copy of Apache so that it includes the `mod_proxy` module. If you are building from source, the easiest way to do this is to include the `--enable-module=proxy` directive on the `./configure` command line. If not already added for you, make sure that you are loading the `mod_proxy` module at Apache startup time, by using the following directives in your `httpd.conf` file:
>        LoadModule proxy_module  {path-to-modules}/mod_proxy.so
>        AddModule  mod_proxy.c
> 3. Include two directives in your `httpd.conf` file for each web application that you wish to forward to Tomcat. For example, to forward an application at context path `/myapp`:
>        ProxyPass         /myapp  http://localhost:8081/myapp
>        ProxyPassReverse  /myapp  http://localhost:8081/myapp
> 4. which tells Apache to forward URLs of the form `http://localhost/myapp/*` to the Tomcat connector listening on port 8081. Configure your copy of Tomcat to include a special `<Connector>` element, with appropriate proxy settings, for example:
>        <Connector port="8081" ...
>                      proxyName="www.mycompany.com"
>                      proxyPort="80"/>
which will cause servlets inside this web application to think that all proxied requests were directed to `www.mycompany.com` on port 80. It is legal to omit the `proxyName` attribute from the `<Connector>` element. If you do so, the value returned by `request.getServerName()` will by the host name on which Tomcat is running. In the example above, it would be `localhost`. If you also have a `<Connector>` listening on port 8080 (nested within the same Service element), the requests to either port will share the same set of virtual hosts and web applications. You might wish to use the IP filtering features of your operating system to restrict connections to port 8081 (in this example) to be allowed only from the server that is running Apache. Alternatively, you can set up a series of web applications that are only available via proxying, as follows: Configure another `<Service>` that contains only a `<Connector>` for the proxy port. Configure appropriate Engine, Host, and Context elements for the virtual hosts and web applications accessible via proxying. Optionally, protect port 8081 with IP filters as described earlier. When requests are proxied by Apache, the web server will be recording these requests in its access log. Therefore, you will generally want to disable any access logging performed by Tomcat itself. When requests are proxied in this manner, all requests for the configured web applications will be processed by Tomcat (including requests for static content). You can improve performance by using the `mod_jk` web connector instead of `mod_proxy`. `mod_jk` can be configured so that the web server serves static content that is not processed by filters or security constraints defined within the web application's deployment descriptor (`/WEB-INF/web.xml`).
Apache 2.0 Proxy Support
The same instructions hold true as for 1.3. (Except in Apache 2.0, you may omit `AddModule mod_proxy.c`)
Comments
Notice: This comments section collects your suggestions on improving documentation for Apache Tomcat. If you have trouble and need help, read Find Help page and ask your question on the tomcat-users mailing list. Do not ask such questions here. This is not a Q&A section. The Apache Comments System is explained here. Comments may be removed by our moderators if they are either implemented or considered invalid/off-topic.
Copyright © 1999-2013, Apache Software Foundation