fix Dockerfile.zefie, add docker.sh helper

docker.sh

@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+DOCKER_IMAGE="zefie/llvm-mingw"
+CURDIR="$(realpath "$(dirname "${0}")")"
+
+get_latest() {
+# Find all tags for ${DOCKER_IMAGE}, sort by creation timestamp (descending), return the newest
+	latest_image=$(docker images --format '{{.CreatedAt}}\t{{.Repository}}:{{.Tag}}' ${DOCKER_IMAGE} \
+	  | sort -r \
+	  | cut -f2- \
+	  | grep -v latest \
+	  | head -n 1)
+
+	if [[ -z "$latest_image" ]]; then
+		echo "No images found for repository '${DOCKER_IMAGE}'" >&2
+  		exit 1
+	fi
+
+	echo "$latest_image"
+}
+
+if [ "${1}" == "build" ]; then
+	THETAG=$(date +%Y%m%d)
+	cd "$(realpath "$(dirname "${0}")")"
+	docker buildx build --tag "${DOCKER_IMAGE}:${THETAG}" .
+elif [ "${1}" == "mklatest" ]; then
+	LATEST=$(get_latest)
+	if [ -z "${LATEST}" ]; then
+		exit 1;
+	fi
+	docker tag "${LATEST}" ${DOCKER_IMAGE}:latest
+	echo "Set ${DOCKER_IMAGE}:latest to ${LATEST}"
+elif [ "${1}" == "run" ]; then
+	shift
+	IMAGE=$(get_latest)
+	if [ -z "${IMAGE}" ]; then
+		exit 1;
+	fi
+	export EMBEDDED=1
+	CMD=(docker run --rm -it "${IMAGE}" "${@}")
+	echo "Executing ${CMD[@]}"
+	"${CMD[@]}"
+elif [ "${1}" == "push" ]; then
+	# push dated one first, then latest
+	"${0}" mklatest
+	IMAGE=$(get_latest)
+	echo "Pushing ${IMAGE}"
+	docker push "${IMAGE}"
+	echo "Pushing ${DOCKER_IMAGE}:latest"
+	docker push "${DOCKER_IMAGE}:latest"
+else
+	echo "Usage: ${0} [build|run|mklatest]"
+	exit 1;
+fi
+