Category Education

Operating System Upgrades within a Kubernetes Cluster  See which pods are running on which nodes: kubectl get pods -o wide Evict the pods on a node: kubectl drain [node_name] –ignore-daemonsets Watch as the node changes status: kubectl get nodes -w…

Upgrading Kubernetes Get the version of the API server: kubectl version –short Release the hold on versions of kubeadm and kubelet: sudo apt-mark unhold kubeadm kubelet Install version 1.18.5 of kubeadm: sudo apt install -y kubeadm=1.18.5-00 Hold the version of…

Metrics Server Kubernetes Metrics Server Metrics Server is a scalable, efficient source of container resource metrics for Kubernetes built-in autoscaling pipelines. Metrics Server collects resource metrics from Kubelets and exposes them in Kubernetes apiserver through Metrics API 1. Download the metric…

Pod Security Set the security context for a Pod To specify security settings for a Pod, include the securityContext field in the Pod specification. The securityContext field is a PodSecurityContext object. The security settings that you specify for a Pod apply to all Containers in the…

Init Containers Init Containers This page provides an overview of init containers: specialized containers that run before app containers in a Pod. Init containers can contain utilities or setup scripts not present in an app image. You can specify init containers…

Kubernetes-Helm Charts HELM (The package manager for Kubernetes)Helm is the best way to find, share and use software built for kubernetes Installation Steps On Ubuntu  curl | sudo apt-key add –  sudo apt-get install apt-transport-https –yes  echo “deb all…

Kuberentes Kompose Translate a Docker Compose File to Kubernetes Resources  What’s Kompose? It’s a conversion tool for all things compose (namely Docker Compose) to container orchestrators (Kubernetes or OpenShift). 1. curl -L -o kompose 2.   mv kompose   chmod 777 Create a docker-compose.yaml…

Kubernetes – liveness and Readiness Liveness Probe Many applications running for long periods of time eventually transition to broken states, and cannot recover except by being restarted. Kubernetes provides liveness probes to detect and remedy such situations. In this exercise,…

Kubernetes – Resource Quota A resource quota, defined by a ResourceQuota object, provides constraints that limit aggregate resource consumption per namespace. It can limit the quantity of objects that can be created in a namespace by type, as well as the total…

Kubernetes Volumes (emptyDir,hostPath,Persistence Volume) When a Container crashes, kubelet will restart it, but the files will be lost – the Container starts with a clean state. Second, when running Containers together in a Pod it is often necessary to share files between…