theckang / kubernetes-taw

kubernetes-taw

This tutorial provides a walkthrough of Kubernetes fundamentals.

Costs

This tutorial uses billable components of Google Cloud Platform, including:

• Google Kubernetes Engine
• Google Cloud Load Balancing

Use the Pricing Calculator to generate a cost estimate based on your projected usage.

Before you begin

1. Create a Google Cloud Platform project.

2. Enable billing for the project.

3. Enable the Google Kubernetes Engine API.

4. Open Cloud Shell.

Setup

1. Clone and cd to this repo:

git clone https://github.com/theckang/kubernetes-taw
cd kubernetes-taw

2. Create the Kubernetes Engine cluster:

gcloud container clusters create cluster-1 --zone us-west1-a

3. Set the zone of cluster-1:

gcloud config set compute/zone us-west1-a

4. Get authentication credentials to cluster-1:

gcloud container clusters get-credentials cluster-1

Pod

Basic Example

Review the YAML:

cat pod.yaml
cat busybox.yaml

Deploy with Kubernetes:

kubectl create -f pod.yaml
kubectl create -f busybox.yaml

Get pods:

kubectl get pods

Test webserver:

POD_IP=$(kubectl get pod pod-example -o jsonpath='{.status.podIP}''
kubectl exec busybox curl $POD_IP

Sidecar Example

Review the YAML:

cat sidecar.yaml

Deploy with Kubernetes:

kubectl create -f sidecar.yaml

Get pod:

kubectl get pod sidecar-example

Test webserver:

SIDECAR_IP=$(kubectl get pod sidecar-example -o jsonpath='{.status.podIP}''
kubectl exec busybox curl $SIDECAR_IP

Check if sidecar has access to logs:

kubectl exec sidecar-example --container logrotate ls /logs
kubectl exec sidecar-example --container logrotate cat /logs/access.log

Init Example

Review the YAML:

cat init.yaml

Deploy with Kubernetes:

kubectl create -f init.yaml

Get pod:

kubectl get pod init-example

Check if web server content was initialized:

INIT_IP=$(kubectl get pod init-example -o jsonpath='{.status.podIP}''
kubectl exec busybox curl $INIT_IP

Check if sidecar has access to logs:

kubectl exec sidecar-example --container logrotate ls /logs
kubectl exec init-example --container logrotate cat /logs/access.log

Deployment

Delete the basic pod:

kubectl delete pod pod-example

Get pods:

kubectl get pods

Review the YAML:

cat deployment.yaml

Deploy with Kubernetes:

kubectl create -f deployment.yaml

List deployment:

kubectl get deploy nginx-deployment

List pods in the deployment:

kubectl get pods -l app=nginx

Open another terminal and watch the deployment:

watch kubectl get pods -l app=nginx

Delete one of the pods in the deployment:

POD_ID=$(kubectl get pods -l "app=nginx" -o jsonpath='{.items[0].metadata.name}')
kubectl delete pod $POD_ID

Scale the deployment:

kubectl scale --replicas=3 deployment/nginx-deployment

Get pods in the deployment:

kubectl get pods -l app=nginx

Services

Review the YAML:

cat svc.yaml

Deploy the service:

kubectl create -f svc.yaml

You can also expose the service with:

# kubectl expose deploy nginx-deployment --port=80 --target-port=80

Open another terminal and watch service until EXTERNAL_IP is set:

watch kubectl get svc nginx-svc

Get endpoints:

kubectl get endpoints nginx-svc

Test service:

EXTERNAL_IP=$(kubectl get svc nginx-svc -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
curl $EXTERNAL_IP

Open another terminal and watch Kubernetes dynamically update endpoints:

watch kubectl get endpoints nginx-svc

Scale deployment down:

kubectl scale --replicas=1 deployment/nginx-deployment