Please discard my comment.
I think the error on my comment at #4 is different one from Nobuto's.
I was able to reproduce the issue on my test environment.
This error happens when DNS revers lookup gets fails for some reasons.
In my case, rabbitmq-server charms can't get hostname by 192.168.128.113 then cluster-relation-joined gets failed.
Line 167 in cluster-relation-joined
nodename = get_hostname(get_host_ip(unit_get('private-address')),
fqdn=False)
This error occurs in get_hostname() when revers lookup fails.
Please discard my comment.
I think the error on my comment at #4 is different one from Nobuto's.
I was able to reproduce the issue on my test environment. relation- joined gets failed.
This error happens when DNS revers lookup gets fails for some reasons.
In my case, rabbitmq-server charms can't get hostname by 192.168.128.113 then cluster-
Line 167 in cluster- relation- joined get_host_ ip(unit_ get('private- address' )),
nodename = get_hostname(
fqdn=False)
This error occurs in get_hostname() when revers lookup fails.