Kubernetes - Blue/Green Deployments

Blue/Green deployment strategy in Kubernetes is explained as an alternative to Rolling Updates. Rolling Updates require backward-compatible code and database changes, increasing complexity. Blue/Green deployments solve this by running two separate environments simultaneously — Blue (current) and Green (new) — and switching traffic only after the new version is fully tested. Since Kubernetes lacks native Blue/Green support, the approach uses pod labels and Service selectors: deploy the green environment with new version labels, expose it via a separate pre-prod Service for testing, then update the live Service selector to point to the green pods. A Spring Boot demo app on Minikube illustrates each step with YAML manifests and curl commands.