Hands-on exercises for the "Introduction to Kubernetes" session

intro-k8s-handson.md

An Introduction to Kubernetes

• Basics
• End-to-end example app

Also, check out this kubectl cheatsheet.

Basics

Using Katacoda online or install Minikube locally.

Get an overview of all pods across all namespaces:

$ kubectl get pods --all-namespaces

Launch a simple one-shot pod:

$ kubectl run -it --rm oneshot --restart=Never --image=quay.io/mhausenblas/jump:0.2 -- sh

Launch long-running process (NGINX):

$ kubectl create ns dev

$ kubectl -n dev run webserver --image=nginx:1.13

Scale the webserver deployment to 2 replicas:

$ kubectl -n dev scale deploy/webserver --replicas=2

Create a service webserver for the deployment and check it:

$ kubectl -n dev expose deployment webserver --port=80 --target-port=80

$ kubectl -n dev describe svc -l=run=webserver

List all resources we created:

$ kubectl -n dev get po,rs,deploy,svc

Query the webserver service from within the cluster (from the default namespace):

$ kubectl run -it --rm curlpod --restart=Never --image=quay.io/mhausenblas/jump:0.2 -- curl webserver.dev

End-to-end example app

Vanilla Kubernetes

Using Katacoda online or install Minikube locally.

$ git clone https://github.com/kubernauts/dok-example-us.git && cd dok-example-us

$ kubectl create namespace dok

$ kubectl -n=dok apply -f stock-gen/app.yaml 
$ kubectl -n=dok apply -f stock-con/app.yaml 

$ kubectl -n=dok run -i -t --rm curlpod --restart=Never --image=quay.io/mhausenblas/jump:0.2 -- curl stock-gen:9999/stockdata
$ kubectl -n=dok run -i -t --rm curlpod --restart=Never --image=quay.io/mhausenblas/jump:0.2 -- curl stock-con/average/NYSE:RHT

Using S2I with OpenShift

Using Katacoda

$ oc new-project dok-test

$ oc new-app --docker-image=quay.io/mhausenblas/stock-gen:0.3 \
           --name=stock-gen \
           --env=DOK_STOCKGEN_PORT=9999 \
           --env=DOK_STOCKGEN_CRASHEPOCH=100

$ oc expose dc/stock-gen --port=9999

$ oc new-app https://github.com/kubernauts/dok-example-us \
           --strategy=source \
           --name=stock-con \
           --context-dir=stock-con \
           --env=DOK_STOCKGEN_HOSTNAME=stock-gen \
           --env=DOK_STOCKGEN_PORT=9999

$ oc patch svc stock-con \
   --type=merge \
   --patch='{"spec": {"ports": [ { "name": "http", "port": 9898, "protocol": "TCP", "targetPort": 9898 } ] } }'

$ oc expose svc stock-con --port=9898

$ oc get po,dc,svc,routes