Copying all files from one docker volume to another using wild card characters?

Question

This works because it's copying some_file:

docker run --rm -v target-data:/target -v ~/source:/source alpine cp source/some_file target/

This does not (Using wildcard):

docker run --rm -v target-data:/target -v ~/source:/source alpine cp source/* target/
cp: can't stat 'source/*': No such file or directory

How do copy all the files in the souce volume to the target volume?

Answer 1

The thing is who expand that *:

docker run --rm -v target-data:/target -v ~/source:/source alpine sh -c 'cp -r source/* target/'

You need someone (sh) to expand the * before the program is launched (that is what the shell do before exec cp)