Change Tomcat port on-the-fly

Question

I'd like to store the Tomcat v5.5 port in an environment variable and have Tomcat listen on that port. So far the only way I can see to change the port is by amending $CATALINA_HOME/conf/server.xml. Is there a way to set the port value by supplying an external value when starting Tomcat? I'm running Tomcat on Solaris.

Answer 1

Create a script to launch Tomcat. In the launch script, export JAVA_OPTS to specify a value for the Tomcat property port.http.nonssl (note you can call this property whatever you want).

export JAVA_OPTS=-Dport.http.nonssl=${CATALINA_BASE_PORT}

As you can see, I've set port.http.nonssl to the environment variable ${CATALINA_BASE_PORT}

The script then launches Tomcat:

$CATALINA_HOME/bin/startup.sh

You now need to change the Tomcat $CATALINA_HOME/conf/server.xml file so the non-SSL HTTP connector uses the port.http.nonssl property instead of a hardcoded value.

<!-- Define a non-SSL HTTP/1.1 Connector on port 8080 -->
<Connector port="${port.http.nonssl}" maxHttpHeaderSize="8192"
           maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
           enableLookups="false" redirectPort="8443" acceptCount="100"
           connectionTimeout="20000" disableUploadTimeout="true" />

Now Tomcat will use the port defined in the ${CATALINA_BASE_PORT} environment variable whenever you start it via the new launch script.