Head in the Cloud

The 12 Factor App guidelines suggest separating configuration from code as a best practice. More specifically, it should be deployed separately as well. We shouldn't have to redeploy the entire application in order to make a configuration change. Ideally, we don't want to have to restart our app either.  This eliminates downtime when making configuration changes that don't otherwise require downtime such as timeout values, retry configuration, logging level, and distributed trace sampling rate. For providers that support it, Microsoft.Extensions.Configuration can reload the configuration when it changes. Let's take a look. We'll be using the JSON file provider for these examples with the following configuration: IConfigurationRoot When we change a configuration value, the value in the IConfiguration instance also changes. The key to making it all work is the reloadOnChange parameter. Given a simple console app, we can see the behavior as we modify the appsettin