Running CouchDB-Lucene On Tomcat

As of the time of writing, CouchDB-Lucene (v0.6.0) distribution was bundled with Jetty WebServer and runnable from command line. But if you dive a little bit into the code, you’ll find that the run script basically executes com.github.rnewson.couchdb.lucene.Main, which in turn (1) reads the couchdb-lucene.ini config, (2) creates a Jetty Server, and (3) sets up com.github.rnewson.couchdb.lucene.LuceneServlet on the server.

At work, we had to use Tomcat due to SOE reason, so I spent a bit of time trying to get CouchDB-Lucene running on Tomcat and get it deployed as a .war file. Here’s how we did it, please note that this is the tedious way of doing it, all because I had to integrate CouchDB-Lucene into an existing web app. There’s an easier way to build a .war file mentioned at the end of this post.

1. Unpack couchdb-lucene-<version>.zip .
2. Create a standard web app directory structure with WEB-INF dir.
3. Configure LuceneServlet in your-app/WEB-INF/web.xml .

   <web-app>
   ...
   <servlet>
   <servlet-name>lucene</servlet-name>
   <servlet-class>com.github.rnewson.couchdb.lucene.LuceneServlet</servlet-class>
   </servlet>
   ...
   <servlet-mapping>
   <servlet-name>lucene</servlet-name>
   <url-pattern>/</url-pattern>
   </servlet-mapping>
   ...
   </web-app>

4. Copy all jars from couchdb-lucene-<version>/lib/ to your-app/WEB-INF/lib/ . The jetty-*.jar files can be excluded.
5. Copy couchdb-lucene-<version>/conf/couchdb-lucene.ini and couchdb-lucene-<version>/conf/log4j.xml to your-app/WEB-INF/classes/ .
6. Deploy your-app on Tomcat.
7. Configure the CouchDB external process hook script with the host name and port number where Tomcat is listening on.

There was one catch though, LuceneServlet did not have any no-argument constructor for the web.xml configuration, so that’s one of the changes I had to make. The other change was some file reorganisation so that you can use mvn war:war to generate a target/couchdb-lucene-<version>.war file. Too easy!

I’ll submit a pull request to master later, but in the mean time you can clone my fork to get the patched LuceneServlet and to easily generate the .war file.

Update (27/05/2011): It’s now part of couchdb-lucene master as of 0081272a30dc679effc1cf1298e365b953f568a5, should be included in v0.7.0 .