In figure 3.2, you see several activities taking place:
- When a microservice instance comes up, it’s going to call a service endpoint to read its configuration information that’s specific to the environment it’s operating in. The connection information for the configuration management (connection credentials, service endpoint, and so on) will be passed into the microservice when it starts up.
- The actual configuration will reside in a repository. Based on the implementation of your configuration repository, you can choose to use different implementations to hold your configuration data. The implementation choices can include files under source control, a relational database, or a key-value data store.
- The actual management of the application configuration data occurs independently of how the application is deployed. Changes to configuration management are typically handled through the build and deployment pipeline where changes of the configuration can be tagged with version information and deployed through the different environments.
- When a configuration management change is made, the services that use that application configuration data must be notified of the change and refresh their copy of the application data.
