kubernetes-basics

Kubernetes presentation on the basics plus hands on

Prereqs

1. Create google cloud account
2. Create gcloud cluster gcloud container --project [PROJECT ID] clusters create "kubernetes-basics" --zone "us-west1-a" --machine-type "n1-standard-1" --image-type "GCI" --disk-size "100" --scopes "https://www.googleapis.com/auth/compute","https://www.googleapis.com/auth/devstorage.read_only","https://www.googleapis.com/auth/logging.write","https://www.googleapis.com/auth/servicecontrol","https://www.googleapis.com/auth/service.management.readonly","https://www.googleapis.com/auth/trace.append" --num-nodes "3" --network "default" --enable-cloud-logging --enable-cloud-monitoring --enable-autoupgrade
3. login gcloud auth application-default login ...
4. Destroy cluster gcloud container clusters delete kubernetes-basics --zone "us-west1-a"

demos

Pod

kubectl create -f services/01-hello-k8s/pod.yml

kubectl get pods - yay, it looks like it's running, but how do I know it's running well?

kubectl exec _____ -it -- bash
apt-get update
apt-get install curl
curl localhost

What if the pod stops running?

kubectl delete pod ...

Deployment

kubectl create -f services/01-hello-k8s/deployment.yaml

How does this help?

kubectl delete pod ...

Now its still there!

Service

This is how you make it available:

kubectl expose hello-k8s-deployment --type=LoadBalancer --name=hello-k8s-service

How do I get the IP?

> kubectl get service
NAME               CLUSTER-IP      EXTERNAL-IP      PORT(S)        AGE
hello-k8s-expose   10.31.123.456   35.123.456.789   80:30678/TCP   53s
kubernetes         10.31.123.1     <none>           443/TCP        38m

Sidecar pattern

Create service which polls github every 5 seconds and updates local FS

Inter-service connection and communication

create service which responds either "I'm lonely" or "I see xxx". Spin up twice pointing to each other. Show first one before connection.

Detecting OOM

Note to self: create process which just eats memory. Deploy as 100M limit to demonstrate OOM on pod.