bootstrapping a controller on MAAS with multiple regiond endpoints

[Dmitrii Shcherbakov]

Currently the assumption is that there is a single hostname or IP address that can be used to access MAAS API - this endpoint is used both when a controller is bootstrapped and after bootstrap for machine provisioning.

https://docs.jujucharms.com/2.4/en/clouds-maas

In more complex scenarios MAAS region controllers can be placed into different VLANs and hence have endpoint IP addresses in different subnets - this prevents VIPs from being used as they require a shared layer 2 and a single subnet.

Multiple A records per hostname could be used in a DNS server but there is generally no health-checking for those kinds of setups which will result in guaranteed percentages of failures depending on the number of failed regiond endpoints.

It would be good if Juju supported multiple cloud endpoints per CloudSpec and pooled connections to them trying to use only the ones that respond.

https://github.com/juju/juju/blob/juju-2.4.3/environs/cloudspec.go#L26-L27

In other words:

Currently: 1 endpoint ~ 1 control plane
Required: N endpoints ~ 1 control plane | for a single "cloud region"

[Richard Harding (rharding)]

Thanks this is definitely something we need to keep up with as MAAS scales that Juju is working well with it.

[Dmitrii Shcherbakov (dmitriis)]

Also found this https://bugs.launchpad.net/juju/+bug/1600061

[Canonical Juju QA Bot (juju-qa-bot)]

This bug has not been updated in 2 years, so we're marking it Low importance. If you believe this is incorrect, please update the importance.