Docker - how can I copy a file from an image to a host?

Question

My question is related to this question on copying files from containers to hosts; I have a Dockerfile that fetches dependencies, compiles a build artifact from source, and

Answer 1

A much faster option is to copy the file from running container to a mounted volume:

docker run -v $PWD:/opt/mount --rm --entrypoint cp image:version /data/libraries.tgz /opt/mount/libraries.tgz

real 0m0.446s

** VS **

docker run --rm --entrypoint cat image:version /data/libraries.tgz > libraries.tgz

real 0m9.014s