Incompatibility between region name and kubernetes namespace rules

[Tim McNamara]

The bootstrap process into a k8s cloud fails when that k8s cloud has been defined with a region name that includes capital letters. Kubernetes attempts to create a namespace that includes those capitals (via the controller name?) and then aborts with an error relating to DNS.

See original thread https://discourse.jujucharms.com/t/2032

[Ian Booth (wallyworld)]

The default controller name is composed from <cloud>-<region>, if not specified.

For VM clouds it's just a label so it doesn't matter.
For k8s clouds, a namespace is created from the controller name to contain the controller artefacts. So the name matters.

A workaround is to explicitly name the controller when bootstrapping.

[Nam Nguyen (nammn)]

AFAICT cloud and region names can only be a problem if they contain special chars and/or caps.
Additionally I think that the cloud provider and it's region usually don't contain special chars outside of "-".
Therefore my suggestion would be to:

1. lower-case the name used for creating the namespace

Additionally one could add more sophisticated checking and replacing of invalid special chars (which are not -) and just replace them. But this can and could lead to other unexpected things.

[Richard Harding (rharding)]

I think we're +1 with lowercasing the names by default.

On Fri, Oct 4, 2019 at 8:21 AM Nam Nguyen <email address hidden>
wrote:

> AFAICT cloud and region names can only be a problem if they contain
> special chars and/or caps.
> Additionally I think that the cloud provider and it's region usually don't
> contain special chars outside of "-".
> Therefore my suggestion would be to:
>
> 1. lower-case the name used for creating the namespace
>
> Additionally one could add more sophisticated checking and replacing of
> invalid special chars (which are not -) and just replace them. But this
> can and could lead to other unexpected things.
>
> --
> You received this bug notification because you are subscribed to juju.
> https://bugs.launchpad.net/bugs/1842991
>
> Title:
> Incompatibility between region name and kubernetes namespace rules
>
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[Nam Nguyen (nammn)]

https://github.com/juju/juju/pull/10685 pr