Using Helm to package and deploy your application

Create a new directory for your Helm chart and change into it. Call it hello-kyma-chart and change into it.

Create a new file called Chart.yaml and specify information about the chart, such as the name, version, description, and so on.

1. Add the following content to the file:

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   apiVersion: v2
   name: hello-kyma-chart
   description: A Helm chart for the Hello Kyma example application
   type: application # A chart can be either an 'application' or a 'library' chart.
   version: 0.1.0 # This is the chart version.

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Create a new file called values.yamland specify the default configuration values like replicaCount and image.tag

1. Add the following content to the file:

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   replicaCount: 1
   
   image:
     tag: "1.0.0"

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Create a new directory called templatesand change into it.

Create a new file called deployment.yaml and specify the Kubernetes deployment's definition and use your configuration values.

1. Add the following content to the file:

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   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: {{ .Release.Name }}
   spec:
     replicas: {{ .Values.replicaCount }} 
     selector:
       matchLabels:
         app: {{ .Release.Name }}
     template:
       metadata: 
         labels: 
           app: {{ .Release.Name }}
       spec:
         containers: 
           - name: hello-kyma
             image: ghcr.io/sap-samples/kyma-runtime-learning-journey/hello-kyma:{{ .Values.image.tag }}
             ports:
               - containerPort: 8080 
     strategy:
       type: RollingUpdate
       rollingUpdate:
         maxSurge: 25%
         maxUnavailable: 25%

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   Hint

   Take advantage of the {{ .Release.Name }} and {{ .Values.replicaCount }} placeholders to make use of the configuration values that you specified in the values.yaml file. The {{ Release.Name }} placeholder will be replaced with the name of the Helm release. The {{ .Chart.AppVersion }} placeholder will be replaced with the version of the application that you specified in the Chart.yaml file.

Perform a dry-run of your Helm chart to see if it is valid.

1. Run the following command inside the hello-kyma-chartdirectory:

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   helm template hello-kyma .

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2. You should now see a rendered output of your Helm chart.

Install the Helm chart in your cluster.

1. Run the following command inside the hello-kyma-chartdirectory:

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   helm install hello-kyma-helm .

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2. You should now see the following output:

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   NAME: hello-kyma-helm
   LAST DEPLOYED: Tue Jun 8 11:25:00 2021
   NAMESPACE: default
   STATUS: deployed
   REVISION: 1
   TEST SUITE: None

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3. You can now see the deployment in your cluster:

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   kubectl get deployments

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4. You should now see the following output:

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   NAME     READY   UP-TO-DATE   AVAILABLE   AGE
   hello-kyma-helm     1/1     1           1           2m

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Update the values.yaml file and change the replicaCount to 2.

Update the Helm chart in your cluster.

1. Run the following command inside the hello-kyma-chart directory:

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   helm upgrade hello-kyma-helm .

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2. You should now see the following output:

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   Release "hello-kyma-helm" has been upgraded. Happy Helming!
   NAME: hello-kyma-helm
   LAST DEPLOYED: Tue Jun 8 11:25:00 2021
   NAMESPACE: default
   STATUS: deployed
   REVISION: 2
   TEST SUITE: None

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3. List the deployment with kubectl:

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   kubectl get deployments

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4. You should now see the following output:

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   NAME   READY   UP-TO-DATE   AVAILABLE   AGE
   hello-kyma-helm   2/2     2           2            4m

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View the Helm release in the Kyma Dashboard.

1. Open the Kyma Dashboard in your browser.

2. Navigate to the Apps menu item and select Helm Releases. And click the hello-kyma-helm release.

   

3. You should now see the following output:

   

   Note

   Once you discover other Kubernetes objects later in this course, you will be able, for example, to extend your helm chart with other manifests for services, ingresses etc.