Reduce usage of coredns when resolving FQDN

[skourta]

Issue tracker for #19 (comment)
Original comment

Hello, drive by comment, but I'm very interested in this charm, and I would love to see:
ensure if we give an fqdn from k8s in the relation that it's appended with . (full fqdn notation) (canonical/mysql-router-k8s-operator#445)
And if you could take a look at: canonical/mysql-operators#137
For the first point:
We've noticed in deployments from our experience with MySQL that when not having a trailing . clients will launch repeated queries with up to the 5 domain search defined in regular k8s cluster, and the FQDN is always last, and with many clients to your service, this could lead to increased usage of coredns. (it's even more apparent for CMR, since you're client is most likely to go through the 5 domain search before finding the suitable match)
For the second point:
We've noticed issues from the mysql charm when trying to resolve a suitable endpoints style fqdn, especially when there's multiple PTR records. More info on the issue linked.

[reneradoi]

@skourta Can we close this issue after #19 was merged?

[skourta]

Not yet. There will be some changes coming in a PR very soon.