Problem with app dir using release

indeed downs is not a classic assets folder it is a folder in some enclosing dir that is


- maindir
    - downs
    - rel1
    - rel2
    - further releases

and I run

rel1/bin/app start

form the maindir or

rel2/bin/app start

according to the release I want to start

the solution I have found is to use first

plug Plug.Static, at: “/downs”, from: {:app_name, “/downs”}, gzip: false

and then put manually a symlink to the real downs in the app dir which is something like

rel1/lib/app_name-vsn

I have tried to put the symlink when generating the release but I have difficulty copying it to the remote folder