bettergo

The golang repository on Docker Hub is useful for building Go applications in a container without requiring the host to have the Go toolchain installed. Typical usage would look something like this:

mkdir dist
docker run \
    --rm \
    -v `pwd`/dist:/go/bin \
    golang \
    go get github.com/hectane/hectane

If successful, the dist/ directory will contain an executable named hectane when the command completes.

One small problem: dist/hectane is owned by root.

You can still remove the directory with rm but even that will fail if there are subdirectories.

That's where bettergo comes in. Instead of running commands in the container as root, bettergo takes a completely different approach: create a user in the container that matches the current user on the host. What does this look like?

mkdir dist
docker run \
    --rm \
    -v `pwd`/dist:/go/bin \
    -e UID=`id -u` \
    nathanosman/bettergo \
    go get github.com/hectane/hectane

The only differences are the repository name and the addition of the environment variable UID, which is initialized with the current user's ID. The container will then create the appropriate entries in /etc/passwd and /etc/shadow for you and then run the go get command as the new user.

Once the command completes, everything inside dist is owned by... you! That's right, you are the owner of the files inside the directory once again.