Containers, Kubernetes & Platform Engineering

A changed setting may cause the application to start but fail its health check, especially when pods reload configuration differently. Checks to make Compare ConfigMap versions and pod rollout state, inspect startup and readiness logs, and test the application’s expected configuration. Roll back or correct the specific setting through source control...

New nodes may have different labels, taints, runtime versions, images, or network paths from the existing pool. Checks to make Compare node metadata and conditions, inspect scheduling and pod events, and check workload affinity, tolerations, and dependencies. Test a representative workload on new nodes before directing all traffic to the expanded pool....

Runtime updates can change image handling, security defaults, cgroups, or network behavior. Checks to make Compare node runtime versions and events, identify workloads failing on updated nodes, and review runtime release notes and security settings. Test representative images and probes in a staging node pool before broader rollout. When to get help...

A service account change can remove API permissions, alter token mounting, or affect cloud workload identity. Checks to make Compare old and new bindings, token and projection settings, and denied API events. Test the required operations with least privilege in a controlled environment, then roll out gradually and monitor authorization failures. When...

Workloads may rely on metadata endpoints for identity or configuration that are blocked by network policy or pod settings. Checks to make Confirm the workload’s intended identity mechanism, inspect pod and node network rules, and review provider-specific metadata protections. Test access from a controlled pod, and avoid enabling broad metadata access...

A rescheduled pod may land on a node with different network, storage, identity, or configuration conditions. Checks to make Compare node labels and events, volume attachment, service account identity, and environment settings for old and new pods. Check whether node affinity or local state is an undocumented dependency, then test rescheduling...

A Kubernetes Service can list pod endpoints while clients still cannot connect. Network policy, readiness transitions, port mismatches, service mesh rules, or node-level networking can block traffic after endpoint discovery. What to check Compare Service port and targetPort with the container listener, inspect endpoint readiness and pod events, test...

A Deployment can continuously replace pods that start but never pass readiness checks. The underlying issue may be an incorrect health endpoint, slow initialization, unavailable dependency, probe timing, or a service that listens on a different port. What to check Review pod events, container logs, readiness and startup probe configuration, actual...