Master Helm: The Ultimate Guide to Kubernetes Package Management

Helm – Kubernetes Package Management Tool

Table of Contents

1. Concepts

1.1 Helm Core Concepts

Chart : A Helm chart is a package that contains a set of YAML files defining Kubernetes resources. It acts as a template for deploying an application.

Repository : A storage location for charts. Each repository has an index file listing available charts and versions.

Release : An instance of a chart deployed in a cluster. Multiple releases can be created from the same chart, each with its own configuration and status.

The official Helm website provides installation guides, documentation, chart repositories, and community contributions.

1.2 Helm Workflow

Find Chart : Search for the desired chart in a repository.

Install Chart : Use helm install to create a release.

Manage Release : Use helm upgrade, helm rollback, helm uninstall, etc.

Maintain Repository : Add, update, or delete repositories.

1.3 Helm 2 vs Helm 3

Helm 2 : Uses a client‑server model with a Tiller component running in the cluster.

Helm 3 : Removes Tiller; the client talks directly to the Kubernetes API server, simplifying architecture and improving security.

Server‑side Tiller removed.

Release names can be reused across namespaces.

Charts can be pushed to Docker registries.

JSONSchema validation for values.

2. Helm Deployment

2.1 Install Helm

2.1.1 Download Helm client

Visit the Helm GitHub releases page (e.g., https://github.com/helm/helm/releases ) and download the appropriate tarball for your OS.

2.1.2 Install Helm

tar -zxvf helm-v3.6.0-linux-amd64.tar.gz
mv linux-amd64/helm /usr/local/bin/helm

2.1.3 Verify installation

# Run helm version to check the installation
helm version

2.1.4 Enable command completion

# Add completion to bash profile
echo "source <(helm completion bash)" >> ~/.bashrc

2.2 Use Helm to Install a Chart

2.2.1 Add repositories

# Add common Helm repositories
helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo add stable http://mirror.azure.cn/kubernetes/charts
helm repo add aliyun https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts
helm repo add incubator https://charts.helm.sh/incubator

2.2.2 Update repositories

# Refresh the repository index
helm repo update

2.2.3 List repositories

helm repo list

2.2.4 Remove a repository

# Remove the incubator repo
helm repo remove incubator

2.2.5 Show chart information

# Show chart metadata
helm show chart stable/mysql
# Show all details
helm show all stable/mysql

2.2.6 Install a chart

# Install with a custom release name
helm install my-redis bitnami/redis -n default
# Or let Helm generate a name
helm install bitnami/redis --generate-name

2.2.7 List releases

# List all releases
helm ls
helm list

2.2.8 Check release status

# Show status of a release
helm status my-redis

2.2.9 Uninstall a release

# Delete a release
helm uninstall my-redis

3. Helm Chart Custom Templates

3.1 View chart file details

Charts can be downloaded from a repository or created locally. A chart consists of Chart.yaml, values.yaml, and a templates directory containing Kubernetes manifests.

3.2 Pull a chart

mkdir /opt/helm
cd /opt/helm
helm pull stable/mysql
ls
# Output: mysql-1.6.9.tgz

3.3 Inspect chart structure

tar xf mysql-1.6.9.tgz
tree mysql
# Shows Chart.yaml, README.md, templates/, values.yaml, etc.

3.4 Chart structure details

Chart.yaml : Metadata such as name, version, description.

templates : Go‑template files for Deployments, Services, ConfigMaps, Ingress, etc.

values.yaml : Default configuration values.

NOTES.txt : Post‑install messages.

3.5 Create a custom chart

3.5.1 Create chart skeleton

helm create nginx
# Generates a directory with Chart.yaml, values.yaml, and templates/

3.5.2 Modify Chart.yaml and values.yaml

# Edit Chart.yaml to set name, version, description, etc.
# Edit values.yaml to change replicaCount, image repository, service type, ingress settings, resources, etc.

3.5.3 Lint, package, and install

helm lint nginx
helm package nginx   # Produces nginx-0.1.0.tgz
helm install nginx ./nginx --dry-run --debug   # Validate without installing
helm install nginx ./nginx -n default   # Real installation

3.5.4 Deploy Ingress‑Nginx

wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.30.0/deploy/static/mandatory.yaml
wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.30.0/deploy/static/provider/baremetal/service-nodeport.yaml
kubectl apply -f mandatory.yaml
kubectl apply -f service-nodeport.yaml
# Add host entry and test with curl

3.5.5 Upgrade a chart

# Change service type to NodePort in values.yaml
helm upgrade nginx nginx

4. Rollback

4.1 View release history

helm history nginx

4.2 Perform rollback

helm rollback nginx 1   # Roll back to revision 1
helm history nginx   # Verify the rollback

4.3 Maintain chart files

Update Chart.yaml for metadata and values.yaml for configuration changes.

4.4 Use --set for quick overrides

# Override image tag without editing values.yaml
helm upgrade nginx nginx --set image.tag='1.15'

Helm offers flexible management of Kubernetes applications, with rollback, --set overrides, and powerful templating.

5. Helm Repository (Harbor)

5.1 Install Harbor

# Extract offline installer and configure harbor.yml (hostname, admin password, data volume, etc.)
./install.sh --with-clair --with-chartmuseum   # Enable Clair and ChartMuseum services

5.2 Install Helm Push plugin

# Online installation
helm plugin install https://github.com/chartmuseum/helm-push
# Offline installation (extract tarball into ~/.local/share/helm/plugins/helm-push)

5.3 Configure Helm repository

helm repo add harbor http://192.168.241.24/chartrepo/chart_repo --username=admin --password=Harbor12345

5.4 Push chart to Harbor

cd /opt/
helm push nginx harbor

After pushing, the chart appears in Harbor's chart_repo project.

6. Summary

6.1 Helm command cheat sheet

Command

Description

Completion

Enable command completion

Create

Create a new chart

Dependency

Manage chart dependencies

Env

Show Helm environment

Get

Retrieve extended release information

Help

Show help for a command

History

Show release revision history

Install

Deploy a chart

Lint

Validate chart syntax

List (ls)

List releases

Package

Package a chart into a tgz

Plugin

Manage Helm plugins

Repo

Add, list, remove, update repositories

Rollback

Rollback a release to a previous revision

Search

Search for charts

Show

Display chart information

Status

Show release status

Template

Render templates locally

Test

Run chart tests

Uninstall

Delete a release

Upgrade

Upgrade a release

Verify

Verify chart signatures

Version

Show Helm version

These commands cover the full lifecycle of Helm chart development, deployment, and management in Kubernetes environments.