Relative path in Context.xml

Question

Is there a way to set a relative path to the docBase attribute in the context.xml of a web application, so it is outside of the appBase directory of the tomcat server instance?

I would like to be able to share the context configuration between computers and have the app living in a directory, not a war file. That way i can compile the classes directly into that directory (in my project development directory) and have tomcat use these classes without any copying/packaging needed.

I am using the tomcat 8.0.0-RC5. My directory Layout is:

/home/david/projects/frontend/web-content          <-- the static html files
/home/david/projects/frontend/web-content/WEB-INF  <-- the WEB-INF with the web.xml
/home/david/projects/tomcat                        <-- tomcat base directory
/home/david/projects/tomcat/Catalina/localhost     <-- holds the frontend.xml context configuration

I have tried

<?xml version="1.0" encoding="UTF-8"?>
<Context path="/frontend" docBase="../../frontend/web-content">
</Context>

but that did not work. The whole path before /web-content seems to be ignored. The log says:

The main resource set specified [/home/david/projects/tomcat/webapps/web-content] is not valid

The Tomcat 8 documentation for the context container says:

You may specify an absolute pathname for this directory or WAR file, or a pathname that is relative to the appBase directory of the owning Host.

Does relative here mean a strict subdirectory of appBase (no .. allowed)?

Setting an absolute path works without problems. The configuration

<?xml version="1.0" encoding="UTF-8"?>
<Context path="/frontend" docBase="/home/david/projects/frontend/web-content">
</Context>

works, but it is specific to my computer. So I cannot share the context configuration without modification anymore.

I could create a symbolic link inside the appBase directory of the tomcat server and let it point to the web-content folder of my application. This would work, but I would have different configurations (symbolic links) on linux and windows machines.

Answer 1

Just taking only the last name of relative path names and ignoring the first parts is most likly a bug in tomcat. Relative path names should work or must throw errors. But ignoring parts is bad. A workaround could be using an absolute path name like this: <Context docBase="${catalina.home}/../www.war"

I just reading the changelog of Tomcat 8.0.15. The bug should be fixed(!): "Correctly handle relative values for the docBase attribute of a Context."