Kubernetes provides a convenient way to rollback an application to an older version based on ReplicaSet and Deployment objects. By default, Kubernetes keeps 10 previous ReplicaSets and lets you roll back to any of them. However, one thing needs to be pointed out. A rollback does not include configuration stored inside ConfigMap and Secret. Sometimes it is desired to rollback not only application binaries, but also configuration.

Fortunately, Spring Boot gives us really great possibilities for managing externalized configuration. We may keep configuration files inside the application and also load them from an external location. On Kubernetes we may use ConfigMap and Secret for defining Spring configuration files. The following definition of ConfigMap creates application-rollbacktest.yml Spring configuration containing only a single property. This configuration is loaded by the application only if Spring profile rollbacktest is active.