Skip to main content

Simplest hello world

Easy-to-do tutorial to get started in no time !

Prerequisites​

To run this onboarding tutorial, we should first have:

  • a k8saas cluster deployed
info

To ask and set up your own cluster, look at the section Getting Started.

And downloaded the following files:

Tutorial​

The application is a simple website, displaying a welcome page on port 80.

Get your credentials​

az aks get-credentials  --name "$K8SAAS_RESOURCE_NAME"  --resource-group "$K8SAAS_RESOURCE_NAME" \
note

The cluster name and the resource group name are the same within k8saas.

Deploy the application​

Deploy the application, composed of :

  • a kubernetes Deployment object: which spin up the application pod (container) and make sure it's up and running at all time;
  • a kubernetes Service object: which exposes the pod internally.
warning

Before applying the configuration. We will need to update the downloaded files.

Update DNS zone​

You will need to update the file hello-world-ingress.yaml with the right DNS zone and at the same time we will change the host to be sure it's unique and not interfering with another project.

Look and replace:

spec:
  ingressClassName: nginx
  rules:
  - host: hw-ingress-<VALUE_TO_CHANGE>.demo.<DNS_ZONE>
...
  tls:
  - hosts:
    - hw-ingress-<VALUE_TO_CHANGE>.demo.<DNS_ZONE>

With the DNS zone information that was in the onboarding email sent to you. If you do not have this information you can always run this:

note

Possible DNS Zone for K8SaaS clusters:

  • kaas.thalesdigital.io
  • k8saas.thalesdigital.io
  • prod.k8saas.thalesdigital.io
  • eu.k8saas.thalesdigital.io
  • eu2.k8saas.thalesdigital.io
kubectl get ingress -n monitoring

It should return something like this:

NAME                          CLASS   HOSTS                                                             ADDRESS         PORTS     AGE
prometheus-operator-grafana   nginx   grafana.k8saas-rbo-sandbox.eu.k8saas.thalesdigital.io        20.50.218.145   80, 443   389d

Now with the information from the previous command, update hello-world-ingress.yaml with the right information. Here we've replaced hw-ingress-<VALUE_TO_CHANGE> with hw-ingress-rbo-sandbox to be unique like suggested earlier.

spec:
  ingressClassName: nginx
  rules:
  - host: hw-ingress-rbo-sandbox.demo.eu.k8saas.thalesdigital.io
...
  tls:
  - hosts:
    - hw-ingress-rbo-sandbox.demo.eu.k8saas.thalesdigital.io

Using the following commands:

# this start a hello world pod
kubectl apply -f aks-helloworld-one.yaml --namespace dev
# look at your pods
kubectl get pods -n dev
# NAME                                  READY   STATUS    RESTARTS   AGE
# aks-helloworld-one-56c7b8d79d-sm4c6   2/2     Running   0          10m

Expose the application​

The second file deploys a kubernetes Ingress object that binds the application to a DNS domain: e.g. hw-ingress-rbo-sandbox.demo.eu.k8saas.thalesdigital.io.

Use the command:

kubectl apply -f hello-world-ingress.yaml --namespace dev

Now, open a browser and consult your first application: e.g. https://hw-ingress-rbo-sandbox.demo.eu.k8saas.thalesdigital.io or in a shell:

curl -k https://hw-ingress-rbo-sandbox.demo.eu.k8saas.thalesdigital.io

If you are not sure of your hostname you can run this command:

kubectl get ingress -n dev
note

Once your ingress is deployed, it might take some time before an IP is allocated and DNS configured. Wait a couple of minutes, then you can test with host or nslookup e.g. host hw-ingress-rbo-sandbox.demo.eu.k8saas.thalesdigital.io nslookup hw-ingress-rbo-sandbox.demo.eu.k8saas.thalesdigital.io

Remove your test​

kubectl delete -f aks-helloworld-one.yaml --namespace dev
kubectl delete -f hello-world-ingress.yaml --namespace dev