How to mount a Windows' folder in Docker using Powershell (or CMD)?

Question

I would like to run a container on Windows 10 and mount my local folder to a folder in the container. Let's take the following command as an example, but any container will do.

 docker run -v "$(pwd)":/data -- name mongo -d mongo mongod --smallfiles

The issue is with the pwd command. In a Unix environment it returns a relative path, but in Windows it returns an absolute path.

I have tried replacing "$(pwd)" with "." or even "./" with no luck. I also tried ($pwd | Resolve-Path -Relative). In all cases I get

Error parsing reference: ":/data" is not a valid repository/tag.

What works is replacing "$(pwd)" with /d/path/to/my/folder.

docker run -v /d/path/to/my/folder:/data -- name mongo -d mongo mongod --smallfiles

(which is d:\path\to\my\folder) and the mounting is done correctly. However, I'd like to make the command generic, so it can be run from any folder on the host.

Answer 1

As documented /<drive>/<path> is the correct syntax for mounting folders:

On Windows, mount directories using:

docker run -v /c/Users/<path>:/<container path> ...

You can make your command more generic by transforming a path to what Docker expects:

$PWD.Path -replace '^|\\+','/' -replace ':'

like this:

docker run -v "$($PWD.Path -replace '^|\\+','/' -replace ':')":/data -- ...

If the drive letter must be lowercased (can't test, since I don't have Docker running on Windows) it gets a little more complicated. If you can lowercase the entire string you could replace $PWD.Path with $PWD.Path.ToLower(). If you must lowercase just the drive letter and preserve case in the rest of the path you could use a callback function:

$re = [regex]'^([A-Z]):'
$cb = { $args[0].Groups[1].Value.ToLower() }

docker run -v "$($re.Replace($PWD.Path, $cb) -replace '^|\\+','/')":/data -- ...

Answer 2

This works in PowerShell:

docker run --rm -v ${PWD}:/data alpine ls /data

See Mount current directory as a volume in Docker on Windows 10.