created gamedl with build, hbd and itch-download commands

gamedl

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o nounset
+
+IMAGE=gamedl
+CONTAINER=$IMAGE
+
+function build_image () {
+	echo "building $IMAGE..."
+	# docker build --tag "$IMAGE" .
+
+	docker build --tag "$IMAGE" - << EOF
+FROM python:3-alpine
+RUN apk add --no-cache git
+RUN pip install itchiodl
+WORKDIR /usr/src/humble-dl
+RUN \
+        git clone 'https://github.com/xtream1101/humblebundle-downloader.git' . &&\
+        wget -O trovefix.patch 'https://patch-diff.githubusercontent.com/raw/xtream1101/humblebundle-downloader/pull/59.patch' &&\
+        git apply trovefix.patch &&\
+        pip install -e .
+CMD echo "Usage: gamedl <hbd|itch-download|help|build> [<options>]"
+EOF
+}
+
+function check_image () {
+	if ! (docker image inspect "$IMAGE" >/dev/null); then
+		echo "cannot access docker image $IMAGE, it probably does not exist."
+		
+		while true; do
+			read -p "build image? [yn] " yn
+			case $yn in
+				[Yy]* ) build_image; exit ;;
+				[Nn]* ) echo "bye"; exit ;;
+				* )     echo "Please answer yes or no." ;;
+			esac
+		done
+	fi
+}
+
+function run_image () {
+	echo "mounting your local working dir as /dl"
+	docker run -u $(id -u):$(id -g) -v $PWD:/dl -it --rm --name "$CONTAINER" "$IMAGE" "$@"
+}
+
+function show_help () {
+	echo "Usage $0 <command> [<options>]
+Commands:
+	hbd
+		Run the Humble downloader.
+	itch-download
+		Run the Itch.io downloader.
+
+	build
+		(Re)build the gamedl-image.
+	help
+		That is what you are reading now.
+"
+}
+
+cmd="help"
+if [ $# -ge 1 ]; then
+	cmd="$1"
+fi
+
+case "$cmd" in
+	help | h | -h )
+		show_help; exit ;;
+	build )
+		build_image; exit ;;
+	* )
+		run_image $@; exit ;;
+esac
+