Helm Chart OCI Proxy

Transparently proxy and transform Chart Repository styled Helm Charts as OCI artifacts. Now you can address any public Chart Repository styled Helm Chart as an OCI styled artifact.

What is it good for?

This proxy was primary designed after Harbor 2.8 removed support for Chart Repository in favor of OCI. The proxy can be used without Harbor implementing other use cases.

• Store all 3rd party public Helm Charts in your OCI compliant registry. While you can switch the storage and distribution of your Helm Charts easily, it is close to impossible to do so for all sorts of 3rd party Helm Charts.
• Simplify your workflow and tooling by only using the OCI Helm Chart and not a mix of both
• Use it in combination with Skopeo to copy Helm Charts into your OCI registry of choice.

Usage

Use our free hosted version via chartproxy.container-registry.com or host it yourself.

Example

Here is an example of how you can use the service. The following helm command will fetch cert-manager as an OCI Helm Chart, located on charts.jetstack.io.

helm pull oci://chartproxy.container-registry.com/charts.jetstack.io/cert-manager --version 1.11.2

If you do not specify a version, the system will retrieve the latest version.

helm pull oci://stage-proxy.container-registry.com/charts.bitnami.com/bitnami/airflow #will use latest

Use with Harbor

You can use the Helm Chart OCI Proxy with the Harbor Container Registry. Each source needs to be added as an own endpoint.

To proxy, for example charts.jetstack.io you would set the Endpoint URL to https://chartproxy.container-registry.com/charts.jetstack.io.

You also would set the provider to Docker Registry.

After adding the Endpoint, you can proceed with creating the replication rule.

Installation

Install and operate the service yourself, we currently provide a handy Helm Chart, so you can get started quickly.

Our Helm Charts are only available as OCI artifacts. Unlike with traditional Charts where you need to add a Repo first. With OCI, you can install the Chart with one command.

helm install chartproxy --version 1.0.0 --create-namespace --namespace chartproxy oci://8gears.container-registry.com/library/helm-charts-oci-proxy 

Use helm pull to only pull the chart to your local disc, without installing.

helm pull oci://8gears.container-registry.com/library/helm-charts-oci-proxy --version 1.0.0

Installation outside Kubernetes

We also provide the container image that you use with your container runtime of choice.

docker pull 8gears.container-registry.com/library/helm-charts-oci-proxy

Development

Build the binary

./do.sh build

Run Locally

./do.sh run

Run Tests

Tests without specifying a version will pull the latest version.

helm pull --repository-cache=/tmp2 oci://registry:9000/charts.jetstack.io/cert-manager-istio-csr  
helm pull oci://registry:9000/charts.jetstack.io/cert-manager-istio-csr  
helm pull oci://registry:9000/charts.bitnami.com/bitnami/airflow  
helm pull oci://registry:9000/charts.bitnami.com/bitnami/airflow --version 14.0.11  

With specific version

helm pull --repository-cache=/tmp2 oci://registry:9000/charts.jetstack.io/cert-manager-istio-csr --version 0.2.1

Environment Variables

There are not many options in configure the application except the following.

• PORT - specifies port, default 9000
• DEBUG - enabled debug if it's TRUE
• MANIFEST_CACHE_TTL - for how long we have stores manifest and its related blobs, the default value is 60 seconds.
• INDEX_CACHE_TTL - for how long we store chart index file content, the default value is 14400 seconds (4h)
• INDEX_ERROR_CACHE_TTL - for how long we do not try to obtain index files again if it's failed for some reason. The default value is 30 seconds.
• USE_TLS - enabled HTTP over TLS

TODO

• CI/CD Pipeline with GitHub Action
• Add tests
• Add helm index cache layer