Master Helm V3: Deploy, Manage, and Scale Kubernetes Apps with Hands‑On Examples

Helm V3 Features

Architecture change: Tiller removed; Helm connects directly to the API server via kubeconfig.

Release names can be reused across different namespaces.

Charts can be stored in Docker image registries.

Kubernetes application deployment workflow

Write YAML files for deployment, service, and ingress.

1.0 Create deployment template

kubectl create deployment nginx --image=nginx --dry-run -o yaml > deployment.yaml

1.1 Launch nginx pod

kubectl apply -f deployment.yaml

1.2 Verify pod status

kubectl get pods

2.0 Create service resource

kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort --dry-run -o yaml > service.yaml

2.1 Launch service

kubectl apply -f service.yaml

2.2 Verify service ports

kubectl get svc

3.0 Access the nginx service

Use a node IP with the exposed NodePort (e.g., node-ip:31190).

Why Helm?

Helm solves application management problems such as grouping YAML files, reusing them efficiently, and providing version control.

Practical steps

wget http://120.78.77.38/file/helm-v3.0.0-linux-amd64.tar.gz
# or download from the official site
 tar -xf helm-v3.0.0-linux-amd64.tar.gz && cd linux-amd64
 mv helm /usr/bin/   # copy binary to /usr/bin

Configure Helm repository

helm repo add stable http://mirror.azure.cn/kubernetes/charts/

helm repo list

Install a sample application (k8s‑ui)

helm search repo weave   # find the weave‑scope package
helm install ui stable/weave-scope   # install the chart

kubectl get pods   # verify pods are running

Modify the chart

Change the Service type from ClusterIP to NodePort:

kubectl edit svc ui-weave-scope

Create a custom chart

helm create mychart

Replace the default templates with the previously created deployment.yaml and service.yaml, then clean the templates/ directory:

rm -rf templates/*
mv /root/deployment.yaml ./
mv /root/service.yaml ./

Delete the old nginx resources and install the new chart:

kubectl delete svc web
kubectl delete deployment web
helm install web mychart/

Upgrade and list releases

helm upgrade web mychart/
helm list

Scale the deployment

helm upgrade web --set replicaCount=3 mychart/   # scale to 3 replicas

Rollback

helm rollback web 1   # revert to the first version