Deploy Webapp on Kubernetes with Helm Chart

Helm is a quick and easy way to deploy a webapp application instance on a kubernetes cluster with Helm chart. Follow the steps below.

Deploy Webapp on Kubernetes Using with Helm Chart

This guide covers how you can install helm on kubernates cluster and get started using Helm chart for deploying a webapp application on kubernates cluster.

Prerequisites

You must have Kubernetes installed. For the latest release of Helm, we recommend the latest stable release of Kubernetes.

Also Read: What is Kubernetes? | Kubernetes explained

Step 1: Installing Helm From Script on Kubernetes

Helm has an installer script that will automatically grab the latest version of Helm and install it on kubernates locally.

You can fetch that script, and then execute it on kubernates locally.

$ curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3
$ chmod 700 get_helm.sh
$ ./get_helm.sh

Step 2: Create the helmchart

$ helm create webapp

Step 3: Delete everything in templates folder

$ rm -r *

Step 4: Create the yaml files in templates folder

1. Create configmap.yaml with the following data

$ vim configmap.yaml

apiVersion: v1
kind: ConfigMap 
metadata:
  name: {{ .Values.configmap.name }}
  namespace: {{ .Values.namespace }}
data:
  BG_COLOR: '#12181b'
  FONT_COLOR: '#FFFFFF'
  CUSTOM_HEADER: {{ .Values.configmap.data.CUSTOM_HEADER }}

2. Create deployment.yaml with the following data

$ vim deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Values.appName }}
  namespace: {{ .Values.namespace }}
  labels:
    app: {{ .Values.appName }}
spec:
  replicas: 1
  selector:
    matchLabels:
      app: {{ .Values.appName }}
      tier: frontend
  template:
    metadata:
      labels:
        app: {{ .Values.appName }}
        tier: frontend
    spec: # Pod spec
      containers:
      - name: mycontainer
        image: "{{ .Values.image.name }}:{{ .Values.image.tag }}"
        ports:
        - containerPort: 80
        envFrom:
        - configMapRef:
            name: {{ .Values.configmap.name }}
        resources:
          requests:
            memory: "16Mi" 
            cpu: "50m"    # 50 milli cores (1/20 CPU)
          limits:
            memory: "128Mi" # 128 mebibytes 
            cpu: "100m"

3. Create service.yaml with the following data

$ vim service.yaml

apiVersion: v1
kind: Service
metadata:
  name: {{ .Values.appName }}
  namespace: {{ .Values.namespace }}
  labels:
    app: {{ .Values.appName }}
spec:
  ports:
  - port: 80
    protocol: TCP
    name: flask
  selector:
    app: {{ .Values.appName }}
    tier: frontend
  type: LoadBalancer

Step 5: Delete values.yaml file 

$ rm values.yaml

Step 6: Create values.yaml file with the following data

$ vim values.yaml

appName: myhelmapp
namespace: default
configmap:
  name: myhelmapp-configmap-v1
  data:
    CUSTOM_HEADER: 'This app was deployed with helm!'
image:
  name: devopsjourney1/mywebapp
  tag: latest

Step 7: Pull image

$ sudo docker pull devopsjourney1/mywebapp:latest

Step 8: Install the first one

$ helm install webapp-release webapp/ --values webapp/values.yaml

Step 9: The helm list (or helm ls) function will show you a list of all deployed releases

$ helm list

Step 10: Upgrade after templating

$ helm upgrade webapp-release webapp/ --values webapp/values.yaml

Step 11: Uninstall webapp application

To uninstall a release, use the helm uninstall command:

$ helm uninstall webapp-release

Also Read: How To Install and Use Docker on Ubuntu 22.04