Z2JH on Raspberry PI Cluster exec format error on pre puller

[JamesCarscadden]

Bug description

I am attempting to set up the Z2JH chart on a Raspberry PI (arm64) based cluster and am encountering some problems with the pre Puller job/pods. Specifically we get an exec format error (unsurprising since that container does not appear to have an arm64 version.

Expected behaviour

These containers should have arm64 versions

Actual behaviour

exec format error due to no arm64 version

How to reproduce

Use base Z2JH chart (v1.0.0) on an arm64 based cluster node

Your personal set up

Kubernetes v1.21.1 running on Raspberry PI 4 (8Gb) 4 node cluster.
Base OS is current version of Raspbian arm64 distribution
Using Helm to deploy the jupyterhub chart from https://jupyterhub.github.io/helm-chart/

This issue can be worked around by setting

prePuller:
    hook:
      enabled: false
    continuous:
      enabled: false

in the helm values

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[manics]

I suspect the problem is that

zero-to-jupyterhub-k8s/images/image-awaiter/Dockerfile

Line 13 in 1a2ff68

FROM scratch

isn't multi-arch.

[JamesCarscadden]

I don't believe the image-awaiter is the actual problem in this case -- looking closer at the logs the initial problem (if I remove the values configuration mentioned in the issue), is that the 'hook-image-puller' pod fails with 'exec format error' actually on 'image-pull-singleuser' init container (which is probably related to #2145.)

If I add

  prePuller:
    hook:
      enabled: false

to my values, then I encounter the same problem with 'continuous-image-puller' pod. And then finally if I also add the continuous->enabled->false as well then I get past this problem onto other issues. So that's my bad for not looking at this as closely as I should have. Likely this can be considered a duplicate of #2145

[JamesCarscadden]

My initial bug report I made the assumption that since the values were 'prePuller' related, that the exec format error was related to the jupyterhub/k8s-pre-puller container, but that doesn't actually appear to be used anymore. Sorry.

[manics]

That would explain it, the default singleuser image doesn't support ARM64. Shall we close this? There's been a fair bit of activity on jupyter/docker-stacks#1019 and linked PRs so hopefully it won't be too long, in the meantime you can find some alternative ARM64 builds in that thread.

[JamesCarscadden]

Yup close it, I'll wait for #2145

[consideRatio]

Closing as duplicate of #2145