A docker image running NGINX with the nginx-http-flv-module (which includes the nginx-rtmp-module).
Git repository: https://github.com/ngrie/nginx-rtmp-docker
Docker image: https://hub.docker.com/r/ngrie/nginx-rtmp
docker run -d -p 1935:1935 ngrie/nginx-rtmp
The (basic) default configuration can be found here. It can be overridden like this:
docker run -d -p 1935:1935 -v /path/to/nginx.conf:/etc/nginx/nginx.conf ngrie/nginx-rtmp