EntLib 3.1 Configuration - Part I

Recently, when an application that my team had built was deployed to production, an external web service's URL was forgotten to have been set from its test site's to the production site's. So the transactions thought to have completed actually never happened. This caused some interruptions to the business.

We had to rush this deployment one month ahead of schedule because of a business issue. While the rush was partly to blame, I think since the application uses Enterprise Library 3.1 for quite a few of its blocks, one feature could have helped us avoid this hiccup.

Since 3.0, Enterprise Library introduced the environment overrides for configuration. This blog had a good overview of this feature. In a nutshell, the configuration files for the most part are the same between different environments, DEV, Staging, QA and Prod, etc. There are only a few minor things that might be different, such as database connection string, logging threshold, etc. This new Enterprise Library configuration feature saves the differentials in delta config files. And the merge function overrides the original (usually DEV) application config file with the delta to produce the config file for the target environment.

Of course, this feature works out of box for any configuration setting if it can be done through the Enterprise Library configuration console tool, which is also available from Visual Studio .NET 2005 IDE. The list includes the "Application Settings", "Caching", "Logging", etc. "Application Settings" is great for independent name/value pairs but for a set of values and more complicated configuration data schema, a separate configuration section is required. In the next blog, I will show how to create custom EntLib 3.1 configuration sections so that not only can we leverage the environment overrides, but also we can easily use the EntLib config UI to protect sensitive config data with cryptography.