[input.promethues] Pod IP will change after the host is shut down and restarted

[Tong97]

telegraf/plugins/inputs/prometheus/kubernetes.go

Line 201 in 4e6e2a2

if _, ok = p.kubernetesPods[podID]; !ok {

Because the pod IP will change after the host is shut down and restarted, but the pod name will not change, which will cause the plug-in to always access the old IP, so this key cannot be used to determine whether to update the registered IP. Therefore, it is necessary to change the key value calculation or update the registered IP no matter what when there is an update event, because this does not affect anything.

[srebhan]

As you seem to know what needs to be done, would you care to put up a PR fixing this issue!?