Comment 3 for bug 1711747

I am hitting this in 2022.
My openstack is deployed on arm machines, juju bootstrap on top of openstack with arch=arm64.

Case 1 - when no constraint is used, juju assumes amd64
$ juju deploy cs:~containers/kubernetes-worker k8sw1
Located charm "kubernetes-worker" in charm-store, revision 838
Deploying "k8sw1" from charm-store charm "kubernetes-worker", revision 838 in channel stable

Case 2 - arm64 constraint specified explicitely, all is fine
$ juju deploy cs:~containers/kubernetes-worker k8sw2 --constraints arch=arm64
Located charm "kubernetes-worker" in charm-store, revision 838
Deploying "k8sw2" from charm-store charm "kubernetes-worker", revision 838 in channel stable

Case 3 - different constraint is specified, arch is again assumed to be amd64
$ juju deploy cs:~containers/kubernetes-worker k8sw3 --constraints mem=8G
Located charm "kubernetes-worker" in charm-store, revision 838
Deploying "k8sw3" from charm-store charm "kubernetes-worker", revision 838 in channel stable

results

Model Controller Cloud/Region Version SLA Timestamp
kubernetes foundation-openstack openstack_cloud/RegionOne 2.9.22 unsupported 16:07:40Z

App Version Status Scale Charm Store Channel Rev OS Message
k8sw1 waiting 0/1 kubernetes-worker charmstore stable 838 ubuntu waiting for machine
k8sw2 1.23.3 blocked 1 kubernetes-worker charmstore stable 838 ubuntu Missing relation to certificate authority.
k8sw3 error 0/1 kubernetes-worker charmstore stable 838 ubuntu cannot assign unit "k8sw3/0" to machine: cannot assign unit "k8sw3/0" to new machine or container: cannot assign unit "k8sw3/0" to new machine: invalid constraint value: arch=amd64
valid values are: [arm64]

Unit Workload Agent Machine Public address Ports Message
k8sw1/0 waiting allocating 0 waiting for machine
k8sw2/0* blocked idle 1 10.246.204.115 Missing relation to certificate authority.
k8sw3/0 error lost cannot assign unit "k8sw3/0" to machine: cannot assign unit "k8sw3/0" to new machine or container: cannot assign unit "k8sw3/0" to new machine: invalid constraint value: arch=amd64
valid values are: [arm64]

Machine State DNS Inst id Series AZ Message
0 down pending focal no metadata for "focal" images in RegionOne with arches [amd64]
1 started 10.246.204.115 7efd2efe-c746-4557-a9ba-afacfaaefbb3 focal nova ACTIVE