Certified Kubernetes Application Developer (CKAD) Practice Test

The command used to perform a rollback on a Kubernetes deployment is "kubectl rollout undo deployment." This command is specifically designed to revert a deployment to its previous stable state.

When you make changes to a deployment, such as updating the container image or modifying configurations, Kubernetes creates a new replica set for the updated deployment. If you find that the new deployment is not functioning as expected, you can issue the rollback command to revert to the last successful deployment, effectively restoring the previous version of the application.

The "kubectl rollout undo" command is intuitive as it directly references the concept of "rollouts," which encompasses both the deployment of new versions and the possibility of undoing those changes. The command provides a clear and effective pathway to manage and maintain application stability in a Kubernetes environment.

This understanding of rollbacks is critical for maintaining high availability and reliability in Kubernetes-managed applications, especially during a CI/CD workflow where deployments are frequent and sometimes lead to unforeseen issues.