I’m running the “official” RabbitMQ Docker image (https://hub.docker.com/_/rabbitmq) on a Ubuntu 18.04 host on Docker 18.09.2. It runs fine, but the number of reported File Descriptions is 1048576 (which I’d like to modify). But after many hours of searching and experimentation, I can’t find where this value is being set and/or how to modify it (ideally using an “external” method that doesn’t involve building a new image).
If I were just using the basic “docker run” command, I can do this using the command line option “–ulimit nofile=65536:65536”. This works, but I’m starting the RabbitMQ container as part of a “swarm” using the built-in “docker stack deploy” function. Per the latest Docker docs, swarm does not support any way of setting “ulimit”. So my plan was to find an override whatever is setting this to 1048576. I just can’t find it.