Latest Articles - Page 34

Build a container image with Podman or Docker, tag and push it to a registry, and reference it from a Kubernetes Pod or Deployment with imagePullPolicy.

Troubleshoot a Kubernetes Service that does not route traffic by testing Pod IP, EndpointSlices, ClusterIP, DNS, and external exposure in an inside-out workflow.

Diagnose a Kubernetes Deployment that creates no Pods by checking replicas, ReplicaSets, FailedCreate events, selectors, quotas, and admission errors.

Delete a Kubernetes Pod stuck in Terminating by checking grace periods, preStop hooks, finalizers, node reachability, and force-deletion risks.

Fix Kubernetes Pods stuck in Pending or ContainerCreating using scheduling conditions, Events, PVCs, mounts, sandbox checks, image errors, and init logs.

Diagnose and fix Kubernetes ImagePullBackOff and ErrImagePull using Pod events, image references, pull Secrets, policies, TLS, DNS, and platform checks.

Diagnose Kubernetes CrashLoopBackOff using restart counts, events, previous logs, exit codes, commands, probes, configuration, dependencies, and OOM signals.

Troubleshoot Kubernetes Pods using STATUS, conditions, events, logs, exit codes, image checks, probes, volumes, scheduling, and Service routing.

Troubleshoot Kubernetes DNS using Service names, resolv.conf, ndots, CoreDNS health, forwarding, NXDOMAIN, SERVFAIL, and timeout checks.

Learn how Kubernetes control plane and worker node components work together, from kube-apiserver and etcd to kubelet and CRI, and trace a Deployment from kubectl apply to running Pods and Service endpoints.

Isolate Kubernetes Pods with NetworkPolicy default-deny rules, allow ingress and egress with podSelector and namespaceSelector, permit DNS, and verify allowed and blocked paths between namespaces.

Create Kubernetes ClusterIP, NodePort, LoadBalancer and headless Services, inspect EndpointSlices, and see how selectors and readiness control traffic.

Use kubectl port-forward to reach Pod, Deployment, and Service ports on your workstation for temporary local testing without NodePort, LoadBalancer, or Ingress.

Configure Kubernetes Ingress rules for host-based and path-based HTTP routing, choose ingressClassName and pathType, add TLS with a Secret, and verify traffic reaches the right Service.

Diagnose Kubernetes OOMKilled and exit code 137 using termination reasons, cgroup debugging inside the container, node dmesg, memory limits, QoS, kubectl top, and controlled OOM tests.

Inspect Linux capabilities in Kubernetes, drop ALL runtime defaults, add back CHOWN or NET_BIND_SERVICE, and compare capabilities with privileged mode.

Learn Kubernetes command and args overrides, environment variables, ConfigMap and Secret references, and Downward API fields with practical examples.

Create a Kubernetes ServiceAccount, inspect projected tokens, request short-lived credentials, disable automount, and verify identity and RBAC authorization.

Create Kubernetes Role and ClusterRole rules, bind them to ServiceAccounts, verify permissions with kubectl auth can-i, and troubleshoot forbidden API errors.

Create Kubernetes ConfigMaps from literals, files, and YAML, then inject configuration into Pods with configMapKeyRef, envFrom, and read-only volume mounts.

Apply Kubernetes ResourceQuota and LimitRange in one namespace, trigger admission failures, inject default requests and limits, and read hard versus used quota consumption.

Configure Kubernetes SecurityContext with practical non-root, fsGroup, read-only filesystem, privilege-escalation, and RuntimeDefault seccomp examples.

Follow a kubectl apply request through Kubernetes authentication, authorization, and admission control, and learn how 401 and 403 responses map to each stage.

Create Kubernetes Secrets from literals, files, and YAML; consume them with secretKeyRef, envFrom, and volumes; and create TLS and registry Secrets.

Configure Kubernetes CPU and memory requests, limits, and QoS classes, and understand scheduling, throttling, OOM behaviour, and Pod-level resources.

Learn when Kubernetes updates ConfigMap and Secret values inside running Pods, why environment variables stay fixed, how volume projection works, and when to roll out new Pods.

Use kubectl exec for running containers with a shell, then kubectl debug ephemeral containers and --copy-to for distroless images, crash loops, and isolated debug Pods.

Use kubectl get, describe, events, and logs to inspect Pod status, warning events, multi-container output, previous logs, and container restart failures.

Install Metrics Server and use kubectl top to monitor CPU and memory for Kubernetes nodes, Pods, and containers with sorting and troubleshooting examples.

Configure Kubernetes liveness, readiness, and startup probes with HTTP, TCP, exec, and gRPC examples, failure tests, and timing guidance.