14 - Smoketest

To smoke test the Kubernetes cluster.

NOTE: The following commands were taken directly from the repository Kubernetes The Hard Way.

Create a generic secret:

kubectl create secret generic kubernetes-the-hard-way \
  --from-literal="mykey=mydata"

ssh onto controller-1, then run:

    sudo ETCDCTL_API=3 etcdctl get \
    --endpoints=https://127.0.0.1:2379 \
    --cacert=/etc/etcd/ca.pem \
    --cert=/etc/etcd/kubernetes.pem \
    --key=/etc/etcd/kubernetes-key.pem\
    /registry/secrets/default/kubernetes-the-hard-way | hexdump -C

Check deployments

Create a deployment for the nginx web server:

kubectl create deployment nginx --image=nginx

List the pod created by the nginx deployment:

kubectl get pods -l app=nginx

Port Forwarding

In this section you will verify the ability to access applications remotely using port forwarding.

Retrieve the full name of the nginx pod:

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

Forward port 8080 on your local machine to port 80 of the nginx pod:

kubectl port-forward $POD_NAME 8080:80

In a new terminal make an HTTP request using the forwarding address:

curl --head http://127.0.0.1:8080

Logs

kubectl logs $POD_NAME

Exec

kubectl exec -ti $POD_NAME -- nginx -v

Services

Expose the nginx deployment using a NodePort service:

kubectl expose deployment nginx --port 80 --type NodePort

Retrieve the node port assigned to the nginx service:

NODE_PORT=$(kubectl get svc nginx \
  --output=jsonpath='{range .spec.ports[0]}{.nodePort}')

Create a firewall rule that allows remote access to the nginx node port:

gcloud compute firewall-rules create kubernetes-the-hard-way-allow-nginx-service \
  --allow=tcp:${NODE_PORT} \
  --network kubernetes-the-hard-way

Retrieve the external IP address of a worker instance:

EXTERNAL_IP=$(gcloud compute instances describe worker-0 \
  --format 'value(networkInterfaces[0].accessConfigs[0].natIP)')

# Make an HTTP request using the external IP address and the nginx node port:

curl -I http://${EXTERNAL_IP}:${NODE_PORT}

Last updated on 17 Aug 2021
Published on 17 Aug 2021