helm-oci-proxy

This take a legacy Helm repo and serve it as OCI registry.

Features

• Turn legacy Helm repo into OCI Helm repo
• Cache with GCS/S3/local file system

TODOs

• Add namespace so we can add proxy multiple legacy helm repos, probably with a config file.
• Add caching with S3. Not tested yet.
• Remove dependency on Helm CLI.
• Add local storage backend
• Fix GCS blob stream instead of redirect because it can be private bucket

Usage

Running locally

go run ./cmd -config config.yaml

Using Docker

You can run helm-oci-proxy using the pre-built Docker image:

docker run -v $(pwd)/config.yaml:/app/config.yaml -p 5000:5000 ghcr.io/tuananh/helm-oci-proxy:nightly --config config.yaml

The container image is built nightly and published to GitHub Container Registry. Both AMD64 and ARM64 architectures are supported.

Testing the proxy

Try pulling your helm chart:

helm pull oci://localhost:5000/argo/argo-cd --version 5.51.3

It should works. You don't need to do helm repo add for OCI registry.

$ helm pull oci://localhost:5000/argo/argo-cd --version 5.51.3
Pulled: localhost:5000/argo-cd:5.51.3
Digest: sha256:4628ea153f308dccceb435e28b9ffcfda0af7eba3c53fd4d6d328323ee71c5fc
$ tar --list -f argo-cd-5.51.3.tgz | head
argo-cd/Chart.yaml
argo-cd/Chart.lock
argo-cd/values.yaml
argo-cd/templates/NOTES.txt
argo-cd/templates/_common.tpl
argo-cd/templates/_helpers.tpl
argo-cd/templates/_versions.tpl
argo-cd/templates/aggregate-roles.yaml
argo-cd/templates/argocd-application-controller/clusterrole.yaml
argo-cd/templates/argocd-application-controller/clusterrolebinding.yaml

Or

$ helm show values oci://localhost:5000/argo/argo-cd --version 5.51.5

License

Copyright 2025 Tuan Anh Tran [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.