Symptoms

• New pods for the checkout-service deployment are stuck in ImagePullBackOff.
• The image reference is registry.company.io/checkout-service:v3.1.0.
• Events show: Failed to pull image: unauthorized: authentication required.
• The deployment worked fine until yesterday. No changes were made to the deployment spec.
• Other deployments in the same namespace pulling from Docker Hub are working normally.
• The cluster uses private registry credentials stored as a Kubernetes secret.
• The ops team rotated registry credentials last night as part of a quarterly security rotation.