/Kubernetes-Certified-Administrator

Online resources that will help you prepare for taking the CNCF CKA "Kubernetes Certified Administrator" Certification exam. with time, This is not likely the comprehensive up to date list - please make a pull request if there something that should be added here.

Kubernetes Certified Administration

Online resources that will help you prepare for taking the Kubernetes Certified Administrator Certification exam.

Disclaimer: This is not likely a comprehensive list as the exam will be a moving target with the fast pace of k8s development - please make a pull request if there something wrong or that should be added, or updated in here.

I tried to restrict the cross references of resources to kubernetes.io. Youtube videos and other blog resources are optional; however, I still found them useful in my k8s learning journey.

Ensure you have the right version of Kubernetes documentation selected (e.g. v1.8 for the current exam) especially for API objects and annotations.

Exam Objectives

These are the exam objectives you review and understand in order to pass the test. The objectives are current as of December 12, 2017.

Core Concepts 19%

apiVersion: apps/v1beta2 # for versions before 1.8.0 use apps/v1beta1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80

Installation, Configuration and Validation 12%

$ kubectl cluster-info
$ kubectl get nodes
$ kubectl get pods -o wide --show-labels --all-namespaces
$ kubectl get svc  -o wide --show-labels --all-namespaces

run a simple deployment, check out https://kubernetes.io/docs/tutorials/

  • Analyse end-to-end tests results
  • Run Node end-to-end tests

Security 12%

Networking 11%

Cluster Maintenance 11%

Troubleshooting 10%

Storage 7%

Application Lifecycle Management 8%

  • Understand Deployments and how to perform rolling updates and rollbacks
  • Know various ways to configure applications
  • Know how to scale applications
  • Understand the primitives necessary to create a self-healing application

Scheduling 5%

  $kubectl describe pods <POD NAME UNDER Investigation>  | grep -A7 ^Events
  • [Know how to configure the Kubernetes scheduler]

Logging/Monitoring 5%

  • Understand how to monitor all cluster components
  • Understand how to monitor applications
  • Manage cluster component logs
    • Master
      • /var/log/kube-apiserver.log - API Server, responsible for serving the API
      • /var/log/kube-scheduler.log - Scheduler, responsible for making scheduling decisions
      • /var/log/kube-controller-manager.log - Controller that manages replication controllers
    • Worker Nodes
      • /var/log/kubelet.log - Kubelet, responsible for running containers on the node
      • /var/log/kube-proxy.log - Kube Proxy, responsible for service load balancing
  • Manage application logs

Tips:

get familiar with:

     $kubectl get pods -o wide --show-labels --all-namespaces

  • In kubectl utilizie --all-namespaces to ensure deployments, pods, objects are on the right name space, and right desired state

  • for events and troubleshooting utilize kubectl describe

     $kubectl describe pods <PODID>
  • the '-o yaml' in conjuction with --dry-run allows you to create a manifest template from an imperative spec, combined with --edit it allows you to modify the object before creation
kubectl create service clusterip my-svc -o yaml --dry-run > /tmp/srv.yaml
kubectl create --edit -f /tmp/srv.yaml