feat: Add a dowloader for the goepel g-api

This is the proprietary software world… We are not allowed to ship this
thing (to create the best user experience), but we are allowed to
download it…

Best: Only a creepy self extracting bash script is available that
requires root permissions and so on. Just run this in a container and
grab the extracted files.

contrib/.gitignore

@@ -0,0 +1 @@
+/out

contrib/download-g-api.sh

@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+
+set -eu
+
+# There is no API. If the download does not work any more (or if there are updates)
+# please check this page: 
+#
+#   https://www.goepel.com/automotive-test-solutions/support/software/g-api-software
+#
+ARCHIVE_NAME="g-api-Setup-2.2.10974_Release_Linux.run.zip"
+RUN_SCRIPT_NAME="${ARCHIVE_NAME%.*}"
+DOWNLOAD_URL="https://www.goepel.com/fileadmin/files/ats/software/g-api/$ARCHIVE_NAME"
+
+is_running_under_podman() {
+    if [[ -n "${container:-}" && "$container" == "podman" ]]; then
+        return 0
+    fi
+    return 1
+}
+
+main() {
+    # If this script is not running under podman, then spawn podman and run
+    # itself within the container.
+
+    # Outside the container.
+    local extractdir
+    extractdir="/mnt$PWD/out"
+    if ! is_running_under_podman; then
+        podman run -it -v "$PWD:/mnt/$PWD" -w "/mnt/$PWD" --rm debian:trixie "$BASH_ARGV0" "$extractdir"
+
+        # Exit the parent script outside the container.
+        exit
+    fi
+
+    # Inside the container.
+    # Catch the directory from the commandline; supplied outside the container.
+    extractdir="$1"
+
+    apt-get install -U -y curl unzip make pciutils xdg-user-dirs
+
+    local tmpdir
+    tmpdir="$(mktemp -d)"
+
+    cd "$tmpdir"
+    curl -L -o "$ARCHIVE_NAME" "$DOWNLOAD_URL"
+
+    unzip "$ARCHIVE_NAME"
+
+    if [[ ! -r "$RUN_SCRIPT_NAME" ]]; then
+        echo "error: $ARCHIVE_NAME is not there!"
+        exit 1
+    fi
+
+    chmod +x "$RUN_SCRIPT_NAME"
+    mkdir -p "$extractdir"
+
+    echo "The goepel installer script is going to be executed now."
+    echo "This scipt will break your system and we do not recommend this to be run on a production system."
+    echo "For reference (especially point 1.4 and 1.5):"
+    echo ""
+    echo "  https://wiki.debian.org/DontBreakDebian"
+    echo ""
+    echo "For this reason, the install script is run in a podman container."
+    echo "The installer will fail but it extracts the library and .so files."
+
+    "./$RUN_SCRIPT_NAME" --target "$extractdir" > "$extractdir/installer.log" 2>&1 || true
+
+    mkdir -p "$extractdir/lib"
+    cd "$extractdir/lib"
+    tar -xvf "../bin/g_api_lib.tar.gz"
+
+    echo "The extracted library will be available in: $extractdir"
+    echo "Headers are in: $extractdir/bin"
+    echo "Shared objects are in: $extractdir/lib"
+}
+
+main "$@"