Comment 7 for bug 1860083

Subscribing ~field-high.

The current workaround is reordering machines in a bundle or to remove some machines and units from a bundle until Juju succeeds. But it's not straightforward to come up with a workaround, and it's really hard to debug which part of a bundle is "wrong" to the current build of Juju.

We have created 4 test cases in total (two cases succeed, and another two cases fail with Juju 2.7.2), and we expect all of 4 cases should pass for reliable deployments in the field.
https://git.launchpad.net/~nobuto/+git/juju-testcase-zones/tree/

Charmed Kubernetes deployments on top of clouds (OpenStack mainly) is critical to assure rack-level and AZ-level redundancy for etcd and kubernetes-master units for high availability. It's not a confirmed theory, but it seems reproducible on other cloud providers such as AWS (in the bug description) so it doesn't looks like a single cloud provider issue.

I have a testbed of OpenStack. So let me know if you need further logs and how to increase the log level for this issue. There are some logs in the link already though.