dejanu

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

dejanu

• Output image name and tag: docker images --format '{{.Repository}} and {{.Tag}}'
• Output image name, tag and elapsed time + timestamp since the image has been created: docker images --format "{{.Repository}}:{{.Tag}} {{.CreatedSince}} --> {{.CreatedAt}}"
• Inspect Cmd for desired : docker inspect -f '{{.Config.Cmd}}' <IMAGE>
• Inspect Entrypoint for desired : docker inspect -f '{{.Config.Entrypoint}} <IMAGE>'
• Search if there are official images for desired : docker search --format "table {{.Name}}\t{{.StarCount}}\t{{.IsOfficial}}" <IMAGE>
• Inspect attached containers to bridge network: docker inspect network bridge --format "{{json .Containers }}"
• Inspect storage: docker info -f 'Storage drive: {{.Driver}} and storage path {{.DockerRootDir}}'
• Inspect container runtimes: docker system info --format "{{.Runtimes}} {{.DefaultRuntime}}"

dejanu

#!/usr/bin/env bash

###########################################
#                                        ##
# @dejanualex: Trivy based image scanner ## 
#                                        ##
###########################################

dejanu

version: '3.1'

services:

  db:
    image: mysql
    command: --default-authentication-plugin=mysql_native_password
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: example

dejanu

#!/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

dejanu

• containers resource usage

# docker stats [OPTIONS] [CONTAINER...]
docker stats --no-stream

• check the container runtimes

docker system info
docker system info --format "Runtimes: {{.Runtimes}} with default {{ .DefaultRuntime }}"

dejanu

#!/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"

dejanu

Nice and eazy Metrics

• Information about Node:

# Gauge type metric

# CPU capacity <cores>
kube_node_status_capacity{resource="cpu"}

# Memory capacity <bytes>

dejanu

#!/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)"

dejanu

# 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)