As per the error, it seems to indicate that max file descriptors  for elasticsearch process is set too low, you may need to increase the limit to unlimited.
firstname.lastname@example.org | ERROR:  bootstrap checks failed
email@example.com | : max file descriptors  for elasticsearch process is too low, increase to at least 
you need to run the container --ulimit flag.
$ docker run --ulimit nofile=65535:65535 <image-tag>
First 65535 is soft limit, second 65535 is hard limit. When you launch the container, of course with -it flag, and enter command ulimit -n you’ll see the limit is 65535 now.