SFTP enabled by default, a pvc claimName is required

[consideRatio]

The SFTP part of the Helm chart is enabled by default.

jupyterhub-ssh/helm-chart/jupyterhub-ssh/values.yaml

Lines 50 to 57 in 69a5bb0

	sftp:
	enabled: true
	replicaCount: 1
	# Not yet implemented. If we want this though, we should probably make sftp a
	# statefulset!
	pvc:
	name: ""

Also, it requires a PVC claimName to be explicitly set by default, otherwise, a user will experience the following error during helm install when the rendered Helm templates fail validation with the k8s api-server because of a empty string as a PVC claimName.

Error: unable to build kubernetes objects from release manifest: error validating "": error validating data: ValidationError(Deployment.spec.template.spec.volumes[0].persistentVolumeClaim): missing required field "claimName" in io.k8s.api.core.v1.PersistentVolumeClaimVolumeSource

---

Suggestions

1. We disable SFTP by default.
2. If SFTP require a PVC, we should probably make it a StatefulSet. A lot of Helm charts transitioned from Deployment resources to StatefulSet's a year back or so btw. By doing this, we become a bit more transparent with intentions etc and we avoid issues like being forced to manually set a Deployment's update strategy to Recreate etc - this is required as only one pod can mount to the typical PVC unless it has ReadWriteMany which is an exception to what is the most common.

[yuvipanda]

We should definitely disable SFTP by default!

The PVC is usually the same PVC used by JupyterHub - so it needs to be ReadWriteMany. As such, I think Deployment is more appropriate. What do you think?

This definitely needs some, any documentation :'(

[glsdown]

Hi @yuvipanda and @consideRatio

Just wondering if either of you found a solution to the issue with the error message:

Error: unable to build kubernetes objects from release manifest: error validating "": error validating data: ValidationError(Deployment.spec.template.spec.volumes[0].persistentVolumeClaim): missing required field "claimName" in io.k8s.api.core.v1.PersistentVolumeClaimVolumeSource

I'm really keen to be able to use the tool, but I know very little about K8s so struggling to work around the issues I'm having with this.

Thanks!

[consideRatio]

I know the feeling @glsdown, when I started learning about k8s I was a high school teacher trying to make JupyterHub available to my students :)

---

@glsdown using helm you can configure values that influence how templates of k8s manifests are rendered. In this case, you should configure...

# my-config.yaml, passed to "helm upgrade" as "--values my-config.yaml"
sftp:
  enabled: false

Note that if you want to use the sftp functionality that is enabled by default but requires configuration of sftp.pvc.name, it becomes more complicated and I won't try address that in this answer.

[glsdown]

Thanks @consideRatio

I’ve jumped in at the deep end rather with all this, so very grateful for you taking the time to respond.