Support oci:// chart pulling

[skylenet]

From helm version 3.5.0 (Release notes) onwards, there is support for pulling charts from OCI registries: https://helm.sh/docs/topics/registries/

Example:

$ export HELM_EXPERIMENTAL_OCI=1 
$ helm pull oci://my-registry.local/my-chart --version 1.0.0

It would be nice if we could also support this on helmsman.

e.g.

...
apps:
  my-app:
    chart: oci://my-registry.local/my-chart
    version: 1.0.0

If you try to do this currently you'll get an error like:

ERROR: chart [ ~/oci:/my-registry.local/my-chart  ] version [1.0.0] can't be found. Inspection returned error: "Error: path "~/oci:/my-registry.local/my-chart" not found" -- If this is not a local chart, add the repo [ helm ] in your helmRepos stanza

[luisdavim]

Hi, would helm install --upgrade oci://my-registry.local/my-chart --version 1.0.0 be valid or do we have to use the pull command?
Do we have to pull and export?

[luisdavim]

I've opened #612 but I haven't tested this or ever used OCI so my assumptions might be wrong there. I also don't have access to a setup where I could test it so I'd appreciate if you could give it a go and provide some feedback.

Thanks.

[skylenet]

hey @luisdavim . Thanks for looking into this 👍

Hi, would helm install --upgrade oci://my-registry.local/my-chart --version 1.0.0 be valid or do we have to use the pull command?
Do we have to pull and export?

Unfortunately helm install doesn't support the oci:// protocol yet. Thus, doing helm pull and helm export is the correct way for now.

I've opened #612 but I haven't tested this or ever used OCI so my assumptions might be wrong there. I also don't have access to a setup where I could test it so I'd appreciate if you could give it a go and provide some feedback.

Thanks.

That's great! I gave it a quick try and the pull and export seem to work fine. I did get the following error afterwards once helm show chart tries to validate the chart:

2021-05-19 14:12:08 DEBUG: helm chart pull xxxxxxx.azurecr.io/helm/my-chart:1.0.0
2021-05-19 14:12:10 DEBUG: helm chart export xxxxxxx.azurecr.io/helm/my-chart:1.0.0 -d /home/default/code/helmsman/cmd/helmsman/example/.helmsman-tmp/tmp438318710
…
2021-05-19 14:12:11 DEBUG: helm show chart /home/default/code/helmsman/cmd/helmsman/example/.helmsman-tmp/tmp438318710/052039960my-chart:1.0.0 --version 1.0.0
2021-05-19 14:12:11 ERROR: chart [ /home/default/code/helmsman/cmd/helmsman/example/.helmsman-tmp/tmp438318710/052039960my-chart:1.0.0 ] version [ 1.0.0 ] can't be found. If this is not a local chart, add the repo [ tmp438318710 ] in your helmRepos stanza. Error output: Getting latest non-local chart's version /home/default/code/helmsman/cmd/helmsman/example/.helmsman-tmp/tmp438318710/052039960my-chart:1.0.0-1.0.0 failed with non-zero exit code 1: exit status 1
output:
--- stdout ---
 
--- stderr ---
Error: file '/home/default/code/helmsman/cmd/helmsman/example/.helmsman-tmp/tmp438318710/052039960my-chart:1.0.0' does not appear to be a gzipped archive; got 'application/octet-stream'
2021-05-19 14:12:11 CRITICAL: chart validation failed

This is what the directory structure looks like after the export:

➜  example git:(oci_support) ✗ ls -la  /home/default/code/helmsman/cmd/helmsman/example/.helmsman-tmp/tmp438318710/
total 12
drwx------ 3 default default 4096 May 19 14:12 .
drwxr-x--- 4 default default 4096 May 19 14:12 ..
-rw------- 1 default default    0 May 19 14:12 052039960my-chart:1.0.0
-rw------- 1 default default    0 May 19 14:12 449162077values.yaml
drwxr-x--- 3 default default 4096 May 19 14:12 my-chart

So for this current directory layout, helm show chart works if I do it like:

helm show chart /home/default/code/helmsman/cmd/helmsman/example/.helmsman-tmp/tmp438318710/my-chart/ --version 1.0.0

[luisdavim]

oh, I need to remove that :<version> thanks for testing it I'll get it fixed after I'm done with my day job today :P

[luisdavim]

I've updated the PR and I think it should work now though I can't be sure since I don't have a way to test it...

[skylenet]

@luisdavim it's working now 🎉

One way to test this could be by running a local registry and pushing some charts there. More about that in here: https://helm.sh/docs/topics/registries/

[luisdavim]

Awesome, thanks.