Containers, Kubernetes & Platform Engineering

A deployment may remain unavailable because new pods cannot schedule, start, pass readiness, or replace old replicas safely. Checks to make Inspect rollout status, replica sets, pod events, logs, resource requests, probes, and image pull results. Compare desired and ready replica counts, then identify the first failing stage before changing rollout...

A pod in ImagePullBackOff cannot retrieve its container image, so the application never reaches startup. The error may be a typo or tag that does not exist, missing registry credentials, a denied repository, or a network or certificate problem between the node and registry. Use events to narrow the cause Run kubectl describe pod and inspect the...

Large images slow pulls and increase storage, but careless cleanup can remove runtime libraries or trust material. Checks to make Measure image layers, use multi-stage builds, pin trusted base images, and copy only required runtime artifacts. Run application tests and vulnerability checks on the final image, then compare startup and pull behavior...

Applications may read secrets only at startup or keep old connections open after a Secret object changes. Checks to make Identify how each workload consumes the secret, plan a controlled rollout, verify external credentials accept the new value, and monitor authentication errors. Remove the old credential only after active pods and dependent services...

Memory pressure can trigger eviction when node capacity is exceeded or workloads consume more than their requests imply. Checks to make Review node conditions, pod events, usage versus requests and limits, and recent workload changes. Identify whether a single pod leaks memory or aggregate demand exceeds capacity. Tune from measurements and protect...

A node may become NotReady because of network plugin issues, resource pressure, kubelet problems, or host failure. Checks to make Review node conditions and events, kubelet and system logs, resource pressure, and control-plane connectivity. Check whether pods were rescheduled and whether storage or local state needs protection before rebooting or...

A ConfigMap update can affect many pods, and workloads may not reload values consistently. Checks to make Record the prior configuration version, identify which pods consume it as environment or mounted files, and plan a controlled rollout to restore the known-good value. Verify every replica and watch application behavior before closing the change....

A small canary can surface issues before broad rollout, but only if traffic, health, and rollback are managed deliberately. Checks to make Select representative traffic, define success and abort thresholds, monitor error and latency metrics, and verify the canary artifact and configuration. Expand in controlled steps and ensure rollback returns traffic...