Configure Symlinks for single directory in Tomcat

Question

Hi,

I have a directory to which a process uploads some pdf files. This process is out of my control.

I need to make those files available through the website using Tomcat.

I have a directory available to the web, with the browser I can see files in it : /var/lib/tomcat5/webapps/test1

So I created a symbolic link to point at the directory with the pdf files : /var/lib/tomcat5/webapps/test1/files/

But I can't see anything in that directory.

How can I enable sym links in the "test1" directory only? I don't want to enable sym links everywhere, just so that directory with pdf files is available to the web.

Thanks

Answer 1

Create a context.xml file in a WEB-INF directory in your web app containing:

<?xml version="1.0" encoding="UTF-8"?>

<Context path="/myapp" allowLinking="true">

</Context>

more here: http://www.isocra.com/2008/01/following-symbolic-links-in-tomcat/

Answer 2

There are a few problems with the solution of creating a WEB-INF/context.xml that contains <Context path="/myapp" allowLinking="true">

The biggest issue is that if a conf/context.xml exists, the allowLinking in the <Context> there takes precedence over a <Context> in a META-INF/context.xml. And if the in the conf/context.xml does not explicitly define allowLinking, that's the same as saying allowLinking="false". (see my answer to a context precedence question)

To be sure that your app allows linking, you have to say <Context override="true" allowLinking="true" ...>.

Another issue is that the path="/myapp" is ignored in a WEB-INF/context.xml. To prevent confusion, it's best to leave it out. The only time path in a <Context> has any effect is in the server.xml, and the official Tomcat docs recommend against putting <Context>s in a server.xml.

Finally, instead of a myapp/WEB-INF/context.xml file, I recommend using a conf/Catalina/localhost/myapp.xml file. This technique means you can keep the contents of your WEB-INF clean, which is the guts of your webapp -- I don't like to risk mucking about in the guts of my webapp. :-)