Saturday, 5 May 2018

Hacking geoserver.war

One easy and efficient way to setup geoserver is as a standalone servlet on an application server like Apache Tomcat. Geoserver is released in many formats one of them is as a web archive (.war file) which contains all the necessary application and configuration files to run geoserver. This is a particularly convenient way to setup geoserver as application servers are available on cloud platforms like Amazon AWS and Azure with a simple deployment procedures and affordable prices, even free in many cases.
There is only one disadvantage in this approach. The .war file contains files with default configurations and they may not be modified during the execution of the application. So every time you need to install geoserver it is necessary to set up the configuration from scratch; nothing is saved on the web archive. This is quite problematic as you will have to setup geoserver from scratch even after a simple reboot of Tomcat or the cloud container. Luckily you may easily hack it.
Web archives .war files are simple zip files, changing their extension or opening the file on a zipping application is enough to reveal their content. As far as it concerns the configuration files of geoserver they are the same on all formats for all platforms. So this is what to do.
Download the platform independent platform binary version  and run the application on your local machine. Set up the application as you will, setup map layers, wms layers, styles and anything else. Don’t forget to change the passwords and security settings.
Delete the files from the data directory of the web archive. Then copy the files from the "data_dir" directory of the locally installed application to the "data" directory of the web archive. Change the extension back to .war and you are fine.
Deploying the modified file on cloud or on an application server will get you a working geoserver with the setting you have applied locally as default settings.