Build docker image from local git working copy on a vargant box identified by vargant directory

vagrant-docker-git-build

#!/bin/bash

set -euo pipefail

if [ "$#" -lt 3 ]; then
    cat << _END_
usage:
    $0 <git dir> <vagrant dir> <docker tag> [<extra docker args>...]
    
note: needs "vcssh", available as https://gist.github.com/kshpytsya/d401ee95268b16f568da6bd6b4cadc1d
On MacOS, this also needs "gnu tar", installable as "brew install gnu-tar".
_END_
    exit 1
fi

TMPDIR=$(mktemp -d)
trap 'rm -rf "$TMPDIR"' EXIT SIGINT

GIT_DIR="$1"
VAGRANT_DIR="$2"
DOCKER_TAG="$3"
shift 3

PATH="/usr/local/opt/gnu-tar/libexec/gnubin:$PATH"

git -C "$GIT_DIR" describe --always --dirty --tags > "$TMPDIR/VERSION"

(
    cd "$GIT_DIR" &&
    git ls-files -z |
        tar c --null --files-from /dev/stdin -C "$TMPDIR" VERSION
) |
    (
        cd "$VAGRANT_DIR" &&
        vcssh -- "DIR=\$(mktemp -d) && tar x -C \$DIR && sudo -H DOCKER_BUILDKIT=1 docker build -t $DOCKER_TAG $* \$DIR && rm -rf \$DIR"
    )