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. v1.13 as of April 2019 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.

CNCF Exam Curriculum repository

Core Concepts 19%

Understand the Kubernetes API primitives
- concepts: Kubernetes Objects
- youtube: Kubernetes Webinar Series - Kubernetes Architecture 101
Understand the Kubernetes cluster architecture
- youtube: A Technical Overview of Kubernetes (CoreOS Fest 2015) by Brendan Burns
Understand Services and other network primitives
- youtube: Life of a Packet [I] - Michael Rubin, Google
- youtube: The ins and outs of networking in Google Container Engine and Kubernetes (Google Cloud Next '17)
Example Nginx deployment:

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%

Design a Kubernetes cluster
Install Kubernetes masters and nodes, including the use of TLS bootstrapping
Configure secure cluster communications
Configure a Highly-Available Kubernetes cluster
Know where to get the Kubernetes release binaries
Provision underlying infrastructure to deploy a Kubernetes cluster
Choose a network solution
Choose your Kubernetes infrastructure configuration
Run end-to-end tests on your cluster
- Some simple commands will cover most cases:

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

For more advanced end to end testing, which may not be covered on the exam, also see:

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%

Use label selectors to schedule Pods
Understand the role of DaemonSets
Understand how resource limits can affect Pod scheduling
Understand how to run multiple schedulers and how to configure Pods to use them
Manually schedule a pod without a scheduler If you require a pod to start on a specific node, you can specify this in POD spec.nodeName, that is what DaemonSets do.
Display scheduler events /var/log/kube-scheduler.log on the control/master node or use kubectl describe as in

  $kubectl describe pods <POD NAME UNDER Investigation>  | grep -A7 ^Events

Know how to configure the Kubernetes scheduler

Logging/Monitoring 5%

Monitoring Kubernetes
Understand how to monitor all cluster components
Pod and Node metrics
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 explain
kubectl cheatsheet
When using kubecctl for investigations and troubleshooting utilize the wide output it gives your more details

     $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

Do you want more?

Kubernauts resources list

About

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.

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