Exercises

Exercise 1: Packaging a Chart as an OCI Image and Examining the Artifact

In this exercise, you will package a Helm chart and push it to an OCI registry, then use Docker to examine the resulting OCI artifact.
This demonstrates how Helm charts are stored as OCI artifacts and how you can inspect them using standard container tools.

Step 1: Create and Package a Chart

Create a new Helm chart for this exercise:

helm create oci-chart

Package the chart:

helm package ./oci-chart

This creates a oci-chart-0.1.0.tgz file (assuming version 0.1.0 in Chart.yaml).

Step 2: Push the Chart to an OCI Registry

Before pushing, ensure you are logged into your OCI registry.
If you are using a local registry or need to log in:

helm registry login <registry-url>

Push the packaged chart to an OCI registry:

helm push oci-chart-0.1.0.tgz oci://<registry-url>/charts

For example, if using a local registry:

helm push oci-chart-0.1.0.tgz oci://localhost:5000/charts

This uploads your chart as an OCI artifact to the registry.

Step 3: Examine the OCI Artifact with Docker

Use Docker to pull and examine the OCI artifact.
First, pull the artifact:

docker pull <registry-url>/charts/oci-chart:0.1.0

For a local registry example:

docker pull localhost:5000/charts/oci-chart:0.1.0

Step 4: Inspect the OCI Artifact

Examine the manifest of the OCI artifact:

docker manifest inspect <registry-url>/charts/oci-chart:0.1.0

This shows the OCI manifest structure, including:
* Media types
* Layers
* Annotations
* Configuration

Step 5: Inspect the Image Details

Get detailed information about the OCI artifact:

docker image inspect <registry-url>/charts/oci-chart:0.1.0

This provides comprehensive information about the artifact, including:
* Architecture
* Created timestamp
* Environment variables
* Labels and annotations
* Layer information

Step 6: View the Artifact Layers

Examine the layers that make up the OCI artifact:

docker history <registry-url>/charts/oci-chart:0.1.0

This shows the layer history, helping you understand how the chart is structured as an OCI artifact.

This exercise demonstrates that Helm charts stored as OCI artifacts can be examined using standard Docker commands, showing how Helm integrates with the OCI ecosystem.