I provisioned the destination hostname in /etc/hosts for testing, but looks like filebeat doesn't honor /etc/hosts entries... Just asking first before putting a bug. Seems like it's not using the normal Linux resolvers.
[root]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6