I do not have a question, but maybe an answer to other threads.
We had issues with lumberjack. We wanted to connect Logstash-to-Logstash and we had issues with our certificates.
Everything worked fine with our self generated certs. But later we wanted to use it in production and had to implement the company pki certs and keys. Lumberjack started to throw errors like: "certificate verify failed"
We figured out that you have to use the root certificate on the lumberjack-ouput. Not a intermediate certificate.