Setup:
- client is amd64, everything else is arm64
- maas -> juju on maas -> k8s -> juju on k8s
Then I bootstrap juju with
`juju bootstrap --bootstrap-constraints 'arch=arm64 ' kubernetes_cloud foundations-kubernetes`
during bootstrapping juju on k8s I get
```
NAMESPACE NAME READY STATUS RESTARTS AGE
controller-foundations-kubernetes controller-0 1/2 CrashLoopBackOff 6 (48s ago) 6m44s
```
```
$ kubectl logs controller-0 -n controller-foundations-kubernetes
Defaulted container "mongodb" out of: mongodb, api-server
exec /bin/sh: exec format error
```
Describing the pod shows
```
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning FailedScheduling 14m default-scheduler 0/11 nodes are available: pod has unbound immediate PersistentVolumeClaims. preemption: 0/11 nodes are available: 11 No preemption victims found for incoming pod..
Normal Scheduled 14m default-scheduler Successfully assigned controller-foundations-kubernetes/controller-0 to sqa-lab2-node-2-arm
Normal SuccessfulAttachVolume 14m attachdetach-controller AttachVolume.Attach succeeded for volume "pvc-32efb3d2-004b-43d5-92ac-9d7efce0a0ae"
Normal Pulling 14m kubelet Pulling image "jujusolutions/juju-db:4.4"
Normal Pulled 14m kubelet Successfully pulled image "jujusolutions/juju-db:4.4" in 5.586025152s (5.586064632s including waiting)
Normal Pulled 14m kubelet Container image "jujusolutions/jujud-operator:2.9.38" already present on machine
Normal Created 14m kubelet Created container api-server
Normal Started 14m kubelet Started container api-server
Normal Created 13m (x4 over 14m) kubelet Created container mongodb
Normal Started 13m (x4 over 14m) kubelet Started container mongodb
Normal Pulled 13m (x3 over 14m) kubelet Container image "jujusolutions/juju-db:4.4" already present on machine
Warning BackOff 4m30s (x56 over 14m) kubelet Back-off restarting failed container mongodb in pod controller-0_controller-foundations-kubernetes(45e493f9-dcd3-441c-8b2c-b7cd137dcfd5)
```
I assume `mongodb` is going to use `jujusolutions/juju-db:4.4` and it is probably amd64 arch.
All this works fine when all is amd64
