Manage Helm charts using Container Registry

Learn how to store and deploy Helm charts using Container Registry.

info

• Estimated time: 30 minutes
• Recommended OS: MacOS
• Prerequisites:
  • IAM access keys
  • Deploy Kubernetes cluster with Kubernetes Engine

About this scenario

This scenario explains how to manage and deploy Helm charts in a Kubernetes cluster using Container Registry. Helm is a Kubernetes package manager that simplifies the deployment and management of complex applications.

Key topics include:

• Create a repository in Container Registry and upload Helm charts
• Create a basic Helm chart for an Nginx web server
• Deploy Helm charts in a Kubernetes cluster
• Manage and upgrade Helm chart versions

Before you start

To proceed smoothly, create a Container Registry and Kubernetes cluster, and install the required tools.

1. Create Container Registry

Container Registry is a cloud service for centrally storing and managing application packages (e.g., Docker images or Helm charts). This step involves creating a repository to store Helm charts.

1. Go to the KakaoCloud console > Container Registry menu and create a repository with the following settings:

   Item	Repository setting
   Visibility	Private
   Repository name	tutorial-helm-cr
   Tag overwrite	Enabled
   Image scan	Automatic

2. Verify that the repository is successfully created in the Container Registry.

2. Create Kubernetes cluster

Create a Kubernetes cluster for the practice session. Refer to the Set up Kubernetes cluster with Kubernetes Engine guide and complete Step 2. Call Kubernetes API with kubectl.

3. Install required tools

For MacOS, install the following tools:

1. Install Helm, the Kubernetes package manager for easy application deployment and management.

   brew install helm

2. Install Docker Desktop, a tool for container execution and image management.

   brew install --cask docker

3. Install the Tree utility, which visually displays directory structures, useful for exploring Helm chart structures.

   brew install tree

Getting started

This practice session guides you through creating a Helm chart, configuring namespaces, deploying the chart, and managing it with Container Registry.

Step 1. Create Helm chart

Helm charts package Kubernetes resources into reusable templates. This step creates a basic Helm chart for an Nginx web server.

1. Create a basic Helm chart.

   helm create my-nginx

2. Check the directory structure.

   tree my-nginx

   The following directory structure should appear:

   my-nginx/
   ├── Chart.yaml
   ├── charts
   ├── templates
   │   ├── NOTES.txt
   │   ├── _helpers.tpl
   │   ├── deployment.yaml
   │   ├── hpa.yaml
   │   ├── ingress.yaml
   │   ├── service.yaml
   │   ├── serviceaccount.yaml
   │   └── tests
   │       └── test-connection.yaml
   └── values.yaml

3. Modify the values.yaml file by setting serviceAccount.create to false. This tutorial does not require a dedicated service account.

Step 2. Create namespace and deploy chart

In this step, create a namespace to logically separate resources and deploy the Helm chart created earlier.

1. Create a new namespace.

   kubectl create ns helm-space

2. Deploy the Helm chart.

   cd ~/my-nginx
   helm install my-nginx-release ../my-nginx/ --debug --namespace helm-space

3. Verify the deployment status.

   kubectl get all -n helm-space ## Verify deployed resources
   helm list --all --namespace helm-space ## Check chart status

   Example output

   NAME             NAMESPACE   REVISION  UPDATED                               STATUS    CHART          APP VERSION
   my-nginx-release helm-space  1         2025-01-03 16:53:29.378136 +0900 KST deployed  my-nginx-0.1.0 1.16.0

Step 3. Authenticate Container Registry

Authenticate the Helm registry to access the Container Registry.

helm registry login ${PROJECT_NAME}.kr-central-2.kcr.dev \
--username ${ACCESS_KEY_ID} \
--password ${SECRET_KEY}

Variable	Description
PROJECT_NAME🖌︎	KakaoCloud project name
ACCESS_KEY_ID🖌︎	Access key ID
SECRET_KEY🖌︎	Secret access key

Step 4. Package and upload chart

Package and upload the Helm chart to the Container Registry.

1. Package the chart.

   helm package my-nginx

2. Upload the packaged chart to the Container Registry.

   • In this scenario, the repository name is fixed as tutorial-helm-cr.

   helm push my-nginx-0.1.0.tgz oci://${PROJECT_NAME}.kr-central-2.kcr.dev/tutorial-helm-cr

   Variable	Description
   PROJECT_NAME🖌︎	KakaoCloud project name

3. Verify the uploaded chart and version (0.1.0) in KakaoCloud console > Container Registry > tutorial-helm-cr > my-nginx.

Step 5. Upgrade chart version

Modify the Helm chart settings and deploy a new version.

1. In values.yaml, set replicaCount to 2 to increase the number of Pod replicas.

2. Update the version in Chart.yaml to 0.1.1 and package the chart.

   helm package my-nginx

3. Upload the new version to the Container Registry.

   helm push my-nginx-0.1.1.tgz oci://${PROJECT_NAME}.kr-central-2.kcr.dev/tutorial-helm-cr

   Variables	Description
   PROJECT_NAME🖌︎	KakaoCloud project name

4. Verify the uploaded chart and version (0.1.1) in KakaoCloud console > Container Registry > tutorial-helm-cr > my-nginx.

5. Upgrade the deployed chart to the new version.

   helm upgrade my-nginx-release oci://${PROJECT_NAME}.kr-central-2.kcr.dev/tutorial-helm-cr/my-nginx --version 0.1.1 --namespace helm-space

   Variables	Description
   PROJECT_NAME🖌︎	KakaoCloud project name

6. Verify the upgrade.

   kubectl get all -n helm-space ## Check that Pod count is 2
   helm history my-nginx-release --namespace helm-space ## View chart upgrade history

   Example output

   REVISION	UPDATED                 	STATUS    	CHART         	APP VERSION	DESCRIPTION
   1       	Fri Jan  3 16:53:29 2025	superseded	my-nginx-0.1.0	1.16.0     	Install complete
   2       	Fri Jan  3 17:28:32 2025	deployed  	my-nginx-0.1.1	1.16.0     	Upgrade complete

Cleanup

Run the following commands to clean up the resources created during this session.

helm uninstall my-nginx-release --namespace helm-space
kubectl delete namespace helm-space