Environment/system variables in server.xml

Question

How can I use environment/system variables in tomcat server.xml, context.xml, etc configuration files?

I tried to use ${ENV_VAR_NAME} (both for environm

Answer 1

Environment variables can be referenced in the server.xml etc by setting the system property org.apache.tomcat.util.digester.PROPERTY_SOURCE to the value org.apache.tomcat.util.digester.Digester$EnvironmentPropertySource.

That system property has been available since 7.0, but EnvironmentPropertySource was not mentioned in the doc until 8.5.

https://tomcat.apache.org/tomcat-9.0-doc/config/systemprops.html

Update (April 2020):

The latest tomcat releases (9.0.34, 8.5.54) now support property replacement in most configuration files: https://tomcat.apache.org/tomcat-9.0-doc/changelog.html#Tomcat_9.0.34_(markt)