[bitnami/external-dns] Cannot pull latest external-dns chart

[iul1an]

Name and Version

bitnami/external-dns 8.6.0

What architecture are you using?

x86-64

What steps will reproduce the bug?

Try to pull the latest chart version, v8.6.0:

$ helm pull --destination /tmp/ --version 8.6.0 --repo https://charts.bitnami.com/bitnami external-dns
Error: invalid_reference: invalid tag
~ took 3s

The previous version of the chart can be pulled without any issues:

$  helm pull --destination /tmp/ --version 8.5.1 --repo https://charts.bitnami.com/bitnami external-dns
~ took 4s

While troubleshooting the issue, I discovered that the latest chart version uses OCI URLs. The change is related to #30110

$ curl -sL https://charts.bitnami.com/bitnami/index.yaml | yq '.entries["external-dns"][] | select(.version == "8.6.0") | .urls'
- oci://registry-1.docker.io/bitnamicharts/external-dns:8.6.0
~ took 1s

vs v8.5.1:

$ curl -sL https://charts.bitnami.com/bitnami/index.yaml | yq '.entries["external-dns"][] | select(.version == "8.5.1") | .urls'
- https://charts.bitnami.com/bitnami/external-dns-8.5.1.tgz
~ took 1s

As a workaround, I'm using the DockerHub OCI repo directly: oci://registry-1.docker.io/bitnamicharts/

Additional information

Helm version: v3.16.2

I'm using ArgoCD to deploy the chart and it runs the exact helm command I mentioned.

[iul1an]

Looks like a bug in Helm itself

This fails:

# Try to pull the chart without adding the repository with "helm repo add"
$ helm pull --version 8.6.0 --repo https://charts.bitnami.com/bitnami external-dns
Error: invalid_reference: invalid tag
~ took 3s

This works:
Add the Bitnami repository

$ helm repo add bitnami https://charts.bitnami.com/bitnami            
"bitnami" has been added to your repositories
~ took 2s

Update the Bitnami repository

$ helm repo update                                        
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "bitnami" chart repository
Update Complete. ⎈Happy Helming!⎈
~ took 1s

Pull the chart

$ helm pull --version 8.6.0 bitnami/external-dns                     
~ took 3s

[carrodher]

EDIT:
As reported in helm/helm#13466, this problem stems from how the helm ... --repo ... command handles an index.yaml file containing OCI URLs.

Why is this issue appearing now?

Historically, Bitnami Helm charts were accessed by adding the Bitnami repository to the Helm CLI:

$ helm repo add bitnami https://charts.bitnami.com/bitnami

or by directly installing/pulling a specific Helm chart using the --repo flag:

$ helm pull --repo https://charts.bitnami.com/bitnami foo

In April 2023, Bitnami introduced support for the OCI format, recommending OCI-based installation as the primary method going forward. For example:

helm pull oci://registry-1.docker.io/bitnamicharts/external-dns --version 8.6.0

As detailed in our recent announcement and #30110, the traditional method is now being deprecated. Consequently, the index.yaml served at https://charts.bitnami.com/bitnami now uses OCI URLs, exposing the above mentioned issue in the Helm CLI's handling of these URLs.

[iul1an]

I switched to OCI. Thank you @carrodher

[primeos-work]

Looks like a bug in Helm itself

Indeed, it got reported there as well: helm/helm#13466 (just as a FYI comment to document it here as well)