What is Helm?

Helm is a package manager tool for K8s which uses a collection of K8s resources to define an application.

Helm charts use a template approach to deploy applications. Templates give structure to projects and are suitable for any application.

Why Helm?

We have YAML files to declare our resources in K8s so why we need helm?

Helm offers several advantages that make it a valuable tool in Kubernetes deployments:

1. Templating and Configuration Management

2. Reusability and Modularity

3. Versioning and Rollbacks

4. Dependency Management

5. Release Lifecycle Management

Prerequisites

• Access to CLI

• Minikube cluster installed and configured

• Helm installed and configured

Step 1.

To create a helm chart

helm create example-app

Go inside the directory created to see the files and directories created by the above command

• The templates/ directory is for template files. When Helm evaluates a chart, it will send all of the files in the templates/ directory through the template rendering engine. It then collects the results of those templates and sends them on to Kubernetes.

• The values.yaml file is also important to templates. This file contains the default values for a chart. These values may be overridden by users during helm install or helm upgrade.

• The Chart.yaml file contains a description of the chart. You can access it from within a template.

• The charts/ directory may contain other charts (which we call subcharts).

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Step 2.

We will configure the imagePullPolicy to Always in this step.

Open the values.yaml in a editor and find the image values:

Now change the image PullPolicy from IfNotPresent to Always.

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Step 3.

Override the chart name in values.yaml file, add values to the nameOverride and fullnameOverride:

After the values are set:

Step 4.

Change networking settings of our example-app.

We will change the networking service type to NodePort.

In the values.yml find the service value:

Change service type from ClusterIP to NodePort

Step 5.

Deploy the helm chart

helm install example-app example-app/ --values example-app/values.yaml

Here the helm install command deploys the app.

Step 6.

Copy the output of helm install ins previous step and run it.

export NODE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].nodePort}" services example-chart)

export NODE_IP=$(kubectl get nodes --namespace default -o jsonpath="{.items[0].status.addresses[0].address}")

Step 7.

To view your application run:

echo http://$NODE_IP:$NODE_PORT

Go to http://192.168.49.2:32757 in your browser. (Your URL might be different)

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