"upgrade in progress" errors persist forever on an API connection

[Roger Peppe]

If a client happens to connect to a controller when it's being upgraded,
it gets an API root that's forever restricted to upgrade methods
only, even though the upgrade itself might complete in a short time.
See https://github.com/juju/juju/blob/develop/apiserver/root.go#L250.

This means that clients that make long-term API connections, such as JIMM,
see persistent errors when a controller has been upgraded.

ISTM that the set of methods available on an API connection should
reflect the connected client, not the server state, so when the server
has successfully upgraded, the available methods should be unrestricted
without the need for a client to make a new connection.

[Casey Marshall (cmars)]

Or, could Juju close all client connections after upgrading? That might be a lot simpler.

[Tim Penhey (thumper)]

I agree with Casey. Simply closing all non-controller connections would be much simpler.

[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.