4.6 Kubernetes

21 entries

• 0394 Install kubectl on Linux, macOS and Windows Install the Kubernetes command-line client with curl, a package manager or winget, verify it, and point it at a cluster with a… Beginner · Step by step · Linux, macOS, Windows Article Concepts · Installing languages & tools 15 Oct 2026
• 0311 What is Kubernetes? Kubernetes is a system that runs containers across many servers, restarting, scaling and connecting them automatically. Beginner · Explains an idea · Any system Article Concepts 15 Oct 2026
• 0312 What is a pod? A pod is the smallest unit Kubernetes runs: one or more containers that share a network address and storage. Beginner · Explains an idea · Any system Article Workloads & services 15 Oct 2026
• 0252 Package a web app as a Helm chart: create, test, install, upgrade and roll back Turn a small nginx web app into your own Helm chart, check it with lint and template, install it into a namespace,… Intermediate · Guided project · Any system Article Helm 15 Oct 2026
• 0251 Learn Kubernetes on your laptop with kind: from first cluster to Ingress Build a throwaway Kubernetes cluster in Docker with kind, deploy a web app with config, secrets and probes, scale it, roll out… Beginner · Guided project · Linux, macOS, Windows Article Concepts · Workloads & services 15 Oct 2026
• 0154 OpenShift app configuration: environment, ConfigMaps, Secrets and persistent storage Set environment variables, load ConfigMaps and Secrets into a Deployment as variables or files, and give it persistent storage with a PersistentVolumeClaim,… Intermediate · Step by step · Any system Article Config, secrets & storage · Deploying applications 15 Oct 2026
• 0153 Expose apps with OpenShift Routes: edge, passthrough and re-encrypt TLS A Route publishes a service on a host name through the OpenShift router. Learn when to use plain HTTP, edge, passthrough or… Intermediate · Step by step · Any system Article Deploying applications · Ingress & networking 15 Oct 2026
• 0142 Fix: ImagePullBackOff and ErrImagePull in Kubernetes The pod cannot start because the node failed to pull the container image. Read the "Failed to pull image" event to see… Intermediate · Fixes an error · Linux Article Troubleshooting 15 Oct 2026
• 0138 Kubernetes RBAC basics: least-privilege access for a service account RBAC controls who may do what in a cluster with Roles, ClusterRoles and bindings. This guide grants a CI service account deploy… Advanced · Step by step · Linux Article Concepts · Config, secrets & storage 15 Oct 2026
• 0143 Fix: CrashLoopBackOff in Kubernetes The container starts, exits, and Kubernetes waits longer before each restart. Read the previous container's logs and its exit code to find… Intermediate · Fixes an error · Linux Article Troubleshooting 15 Oct 2026
• 0140 kubectl cheat sheet: the commands you use every day A compact reference of everyday kubectl commands: contexts and namespaces, listing and inspecting objects, logs and exec, applying changes, rollouts, scaling and… Beginner · Cheat sheet · Any system Article Concepts · Troubleshooting 15 Oct 2026
• 0137 Helm basics: install a chart, override values, upgrade and roll back Helm installs packaged Kubernetes apps called charts. Learn to add a repository, install a release, customize it with values files, upgrade it… Intermediate · Step by step · Any system Article Helm 15 Oct 2026
• 0149 OpenShift vs Kubernetes vs OKD: what OpenShift adds OpenShift is Red Hat's Kubernetes platform and OKD is its community distribution. Both add projects, routes, builds, image streams, Operators and stricter… Beginner · Explains an idea · Linux Article Concepts · Concepts 15 Oct 2026
• 0135 Deploy your first app on Kubernetes A step-by-step tutorial: write a Deployment and a Service in YAML, apply them, reach the app, add health probes, roll out a… Beginner · Step by step · Linux Article Ingress & networking · Workloads & services 15 Oct 2026
• 0136 Persistent storage in Kubernetes: PersistentVolumes, claims and StorageClasses How to give a Pod storage that survives restarts: request it with a PersistentVolumeClaim, let a StorageClass provision it, and mount it.… Intermediate · Step by step · Linux Article Config, secrets & storage · Workloads & services 15 Oct 2026
• 0144 Fix: Pod stuck in Pending with “0/3 nodes are available: Insufficient cpu” The scheduler cannot find a node with enough unreserved CPU for the pod's request. Compare the request with node allocatable resources, then… Advanced · Fixes an error · Linux Article Troubleshooting · Workloads & services 15 Oct 2026
• 0145 Fix: OOMKilled (exit code 137) in Kubernetes A container used more memory than its limit and the kernel killed it. Confirm the reason, measure real usage, then raise the… Advanced · Fixes an error · Linux Article Troubleshooting · Workloads & services 15 Oct 2026
• 0133 Services and Ingress: exposing an app in Kubernetes A Service gives a changing set of Pods one stable address. ClusterIP is internal, NodePort and LoadBalancer reach outside, and an Ingress… Intermediate · Explains an idea · Linux Article Ingress & networking 15 Oct 2026
• 0131 Kubernetes architecture: control plane, nodes, kubelet and etcd A Kubernetes cluster is a control plane that stores and decides the desired state, plus worker nodes that run your containers. This… Beginner · Explains an idea · Linux Article Concepts 15 Oct 2026
• 0132 Pods, ReplicaSets and Deployments explained A Pod runs one or more containers together, a ReplicaSet keeps a fixed number of identical Pods alive, and a Deployment manages… Beginner · Explains an idea · Linux Article Concepts · Workloads & services 15 Oct 2026
• 0134 ConfigMaps and Secrets: configuration outside the image ConfigMaps hold plain settings and Secrets hold sensitive values, injected into Pods as environment variables or files. Secrets are only base64-encoded, not… Intermediate · Explains an idea · Linux Article Config, secrets & storage 15 Oct 2026