agents should ignore invalid API host ports response

[John A Meinel]

If an API server ends up with a corrupted document it can respond to Login requests with an empty list of servers. We should update the code that writes to agent.conf so it refuses to write an empty list. We might want to refuse to remove the IP address that we successfully connected to, but some care would need to be in place for redirects as a result of migration. (If you were migrated to a different controller than it is expected that you would not continue connecting to the old one.)

As for the address we connected to, even if it was a "no longer supported" address for whatever 4eadon, it still worked or we wouldn't have gotten the message. It seems prudent to keep that address around.

[Menno Finlay-Smits (menno.smits)]

There's probably no need to special case model migrations here. During migrations, agents move to the new controller addresses using a mechanism outside of the Login response, and post-migration redirections won't involve the addresses in the Login response.

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

This bug has not been updated in 5 years, so we're marking it Expired. If you believe this is incorrect, please update the status.