Deploying a Kubernetes cluster and managing/setting up a sample app using the UI

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Deploying a Kubernetes cluster using the Infrastructure Editor

To deploy a Kubernetes cluster, you will need to go to your Infrastructure Editor and follow these steps.

1. Add Kubernetes cluster

   Click on Apps on the left hand side and click on Kubernetes. This will create a basic Kubernetes cluster with a master instance pre-selected but no worker nodes.

   

2. Add Worker Nodes

   To add worker nodes and change the configuration of the master node, click on one of the Instance Arrays created, click on Configuration, then click on Kubernetes Node and click on Add new and select the instances you wish to use as nodes. You can also click on Kubernetes Master to change the master node. If you add more worker nodes in the future, they will be added into the cluster automatically once you have hit deploy:

   

   Here we are adding 2x 8.32v2 worker nodes. You will need minimum of 2x worker nodes:

   

3. Change Firewall Rules

   Alter the firewall rules to allow yourself access to the instances and cluster. You can click on Kubernetes Master or Kubernetes Node to change the specific access to each group. For this tutorial, you will need to enable SSH (22) and Kubernetes UI port (62004) access from your IP address (Source) on the Kubernetes Master firewall page . Your IP address is shown at the top of the screen:

   

4. Deploy the infrastructure

   Operations in the MetalCloud are not immediatelly deployed. In fact they can be reverted until the infrastructure is “Deployed”. Click on the big “Deploy” button from the bottom of the screen.

   

   You now have a Kubernetes cluster up and running.

Monitoring and connecting via SSH to the cluster using the UI

1. Monitoring the Kubernetes Cluster

   Once the infrastructure has deployed, you can monitor the Kubernetes cluster by clicking on one of the infrasrtructures and clicking on the URL next to Dashboard This will bring up the dashoboard. You can log in by clicking Retrieve Token under Token and then click on Copy:

   

   You can now paste the token into the web page that is opened and click on Sign In:

   

   Now you will be able to see and monitor your Kubernetes cluster:

   

2. Connect via SSH to the Master node

   To connect via SSH to the Master node, click on one of the instance arrays and click on Instances and Kubernetes Master. Here you can click on the Access Link and it will launch your installed ssh client.You can retrieve the password by clicking on either Reveal or Copy under Initial Password If you have Authenticator configured, you can click on Browser SSH Client under HTML Console :

   

Setting up a sample application on Kubernetes

1. Setting up the initial application

   In this example, the application and service are in a single file. This is based on ASP.NET samples container To set up your initial application, connect to the Master node by SSH as described in the previous section and accept the security warning. Create a directory structure to keep your configuration files in. For this example, we will use /app/ for the application

   Create the file to store the configuration in:

   vim kubernetes-sample.yaml
   

And copy the following into the file and save it

---
kind: Service
apiVersion: v1
metadata:
  name: dotnet-service
spec:
  selector:
    app: dotnet
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: dotnet-deployment
  labels:
    app: dotnet
spec:
  replicas: 2
  selector:
    matchLabels:
      app: dotnet
  template:
    metadata:
      labels:
        app: dotnet
    spec:
      containers:
      - name: dotnet
        image: mcr.microsoft.com/dotnet/samples:aspnetapp
        ports:
        - containerPort: 80

Lastly, you need to use kubectl to create the app and service:

kubectl create -f kubernetes-sample.yaml

You should receive the following output:

[root@instance-60451 apps]# kubectl create -f kubernetes-sample.yaml
service/dotnet-service created
deployment.apps/dotnet-deployment created

1. Setting up the ingress controller

   Next we need to expose the application to the internet using an Ingress controller.

   Create the file to store the configuration in:

   vim kubernetes-sample-ingress.yaml
   

And copy the following into the file and save it:

---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: asp-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - http:
      paths:
        - path: /
          pathType: Prefix
          backend:
            service:
                name: dotnet-service
                port:
                 number: 80

Lastly, you need to use kubectl to create the app and service:

kubectl create -f kubernetes-sample-ingress.yaml

1. Verifying the application and controller are set up.

   If you run:

   kubectl get services --all-namespaces
   

   You should get an output similar to this:

   NAMESPACE              NAME                                 TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
   default                dotnet-service                       ClusterIP      10.103.116.90    <none>        80/TCP                       4m20s
   default                kubernetes                           ClusterIP      10.96.0.1        <none>        443/TCP                      3h52m
   ingress-nginx          ingress-nginx-controller             LoadBalancer   10.109.186.4     84.40.62.50   80:30972/TCP,443:31184/TCP   3h50m
   ingress-nginx          ingress-nginx-controller-admission   ClusterIP      10.107.104.161   <none>        443/TCP                      3h50m
   ingress-nginx          ingress-nginx-defaultbackend         ClusterIP      10.103.243.207   <none>        80/TCP                       3h50m
   kube-system            kube-dns                             ClusterIP      10.96.0.10       <none>        53/UDP,53/TCP,9153/TCP       3h52m
   kubernetes-dashboard   dashboard-metrics-scraper            ClusterIP      10.100.132.173   <none>        8000/TCP                     3h49m
   kubernetes-dashboard   kubernetes-dashboard                 NodePort       10.97.126.97     <none>        443:31708/TCP                3h49m
   

   You should be able to see that the EXTERNAL-IP is set for the Load Balancer ingress-nginx-controller. In this instance 84.40.62.50.

   If you now go back to the infrastructure manager and add a firewall rule to allow port 80, you should be able to view the application in a web browser.

   You will also be able to view the details in the dashboard which you can acces from the infrastruture editor after clicking on one of the Instance Arrays (Kubernetes/Dashboard):