Kubernetes architecture is purely API-driven. The cornerstone of Kubernetes is the reconciliation loop, which has at its core the controller pattern that helps in achieving and maintaining the desired state.
The upgrade process (docs) follows the general procedure of:
- Upgrading the Kubernetes control plane with kubeadm (Kubernetes components and add-ons excluding the CNI)
- If applicable upgrading the CNI network plugin
- Upgrading the Kubernetes packages (kubelet, kubeadm, kubectl) on the control plane and worker nodes
- Upgrading the kubelet config on worker nodes with kubeadm
# check cluster nodes and version
kubectl get no -owide
| #!/usr/bin/env bash | |
| ########################################### | |
| # ## | |
| # @dejanualex: Trivy based image scanner ## | |
| # ## | |
| ########################################### | |
| version: '3.1' | |
| services: | |
| db: | |
| image: mysql | |
| command: --default-authentication-plugin=mysql_native_password | |
| restart: always | |
| environment: | |
| MYSQL_ROOT_PASSWORD: example |
| #!/bin/bash | |
| ## ##################################################################### | |
| ## run concurrently command passed as argv on multiple remote servers ## | |
| ## UPDATE: servers array and user variable ## | |
| ######################################################################## | |
| # define an array of remote servers | |
| servers=("server1.fqdn" "server2.fqdn" "server3.fqdn") | |
| # Function to execute command on a remote server | |
| execute_command() { | |
| server=$1 |
| #!/usr/bin/env bash | |
| ############################################################# | |
| # Purpose: wrapper for inspecting Requests/Limits for Pods ## | |
| # @dejanualex ## | |
| ############################################################# | |
| # read namespace and po | |
| echo -e "Available namespaces are:\n $(kubectl get ns -o=custom-columns=NAMESPACES:.metadata.name) \n" | |
| echo -e "\n Please write the name of the namespace for which you want to know the resource status:\n" |
| #!/usr/bin/env bash | |
| ################################################################################################ | |
| # kubectl wrapper that generates a report concerning cluster state, ## | |
| # which creates a dir with compiled information regarding: ## | |
| # - control plane components status, cluster events, nodes description, and namespace events ## | |
| ################################################################################################ | |
| # Get nodes, componentsstatuses, and pods for control-plane | |
| echo -e "\e[0;32m Cluster Nodes: \e[0m \n $(kubectl get nodes -owide)" |
| # get available k8s versions for AKS, e.g. for location westeurope | |
| az aks get-versions --location westeurope | jq ".orchestrators[] | .orchestratorVersion" | |
| # get available versions for your AKS | |
| az aks get-upgrades --resource-group <resourcegroup_name> --name <aks_name> --output table | |
| # check your k8s version for control plane and woker node pool | |
| az aks show -g <resourcegroup_name> -n <resourcegroup_name>| grep -E "orchestratorVersion|kubernetesVersion" | |
| # update max-surge to 3 nodes, you can use percentage also e.g.50% (for a node surges half of the no of nodes from the node pool) |