title: How to extract files from docker multi-arch images?
body: <p>I'd like to use docker as tool to compile (ningx) modules for multiple architectures (x86-64 and ARM).</p>
  <p>I got my Dockerfile working and it's building each multi-arch image ok but I can't figure out hot to extract (copy) the compiled libraries out of each docker image without actually running the containers and since I can't run the arm image on my local laptop I'm stuck.</p>
  <p>Does anyone have a simple/clever way of doing it?</p>
  <p>Thanks in advance</p>