What is Helm?

What is Helm?

Helm is a package manager for Kubernetes, similar to how apt works for Ubuntu or yum for CentOS. It allows you to manage Kubernetes applications using Helm Charts, which are reusable, versioned, and configurable templates.

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Goal

We will create a Helm Chart to deploy the ram1uj/easy-recipes containerized application (which runs on port 8080) into a Kubernetes cluster.

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Create a Helm Chart

First, install Helm if you haven’t already:

curl -fsSL https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash

Now, create a new Helm Chart:

helm create easy-recipes-chart

This will generate the following structure:

easy-recipes-chart/
│── charts/
│── templates/
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── _helpers.tpl
│   ├── NOTES.txt
│── values.yaml
│── Chart.yaml
│── .helmignore

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Define Application Configuration in values.yaml

Open values.yaml and update the image, container port, and replica count.

replicaCount: 2

image:
  repository: ram1uj/easy-recipes
  pullPolicy: IfNotPresent
  tag: "latest"
  containerPort: 8080

service:
  type: ClusterIP
  port: 80
  targetPort: 8080

ingress:
  enabled: false

resources: {}

nodeSelector: {}

tolerations: []

affinity: []

This sets:

• Replica count = 2 Pods
• Container image = ram1uj/easy-recipes
• Service type = ClusterIP (internal service)

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Define Deployment in templates/deployment.yaml

Modify templates/deployment.yaml to use the values from values.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Release.Name }}-deployment
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: {{ .Release.Name }}
  template:
    metadata:
      labels:
        app: {{ .Release.Name }}
    spec:
      containers:
      - name: {{ .Chart.Name }}
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
        ports:
        - containerPort: {{ .Values.image.containerPort }}

This creates a Deployment with:

• 2 replicas
• Image pulled dynamically from values.yaml
• Port 80 exposed inside the container

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Define a Service in templates/service.yaml

Modify templates/service.yaml to expose the Pods:

apiVersion: v1
kind: Service
metadata:
  name: {{ .Release.Name }}-service
spec:
  type: {{ .Values.service.type }}
  selector:
    app: {{ .Release.Name }}
  ports:
  - protocol: TCP
    port: {{ .Values.service.port }}
    targetPort: {{ .Values.service.targetPort }}

This creates a Service that exposes the Pods.

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Deploy the Helm Chart

Install the Chart in Kubernetes

helm install easy-recipes easy-recipes-chart

Output:

NAME: easy-recipes
LAST DEPLOYED: Mon Feb 25 15:00:00 2025
NAMESPACE: default
STATUS: deployed
REVISION: 1

Verify Deployment

kubectl get pods
kubectl get svc

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Upgrade and Rollback

Update the Chart

If you modify values.yaml, apply changes using:

helm upgrade easy-recipes easy-recipes-chart

Rollback to the previous version

helm rollback easy-recipes 1

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Uninstall the Chart

helm uninstall easy-recipes

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