Enforce new connections like rsyslog does with the rebindinterval option

[businessbean]

Rsyslog provides a rebindinterval option for several output plugins like omelasticsearch, omrelp and omfwd. This is very helpful if you send the messages to Kubernetes ClusterIP service, because it will use a static iptables rule for the load balancing. This would route all traffic from a single source (the Logstash output) to the same pod backing that service.

With the rebindinterval option a new connection (by changing the the source port) will be established every x messages. This will ensure a proper load balancing to all pods backing the ClusterIP service even with the static iptables rules.

Something similar would also be beneficial for this output plugin.

FYI: @richardgilm