Add scripts for a single-command Danbooru deployment.

Add a Docker Compose file that launches a minimal Danbooru instance in a
Docker container with a single command. This is suitable as a quick demo
or for personal use, not for public-facing sites.

To use it, just run `bin/danbooru`. This is a wrapper script that
installs Docker Compose then uses it to start Danbooru.

This will generate a lot of debug output and take several minutes while
it builds the Docker containers. Be patient. When it's done, you should
have an empty booru accessible at http://localhost.

bin/danbooru

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+#
+# This script starts Danbooru by installing Docker and Docker Compose, then
+# starting Danbooru in a container. Danbooru will be available at http://localhost.
+#
+# Usage:
+#
+#     bin/danbooru up   # start Danbooru
+#     bin/danbooru down # stop and remove Danbooru container.
+#     bin/danbooru help # show Docker Compose help
+#
+# Alternatively, if you already have Docker installed, you can just do:
+#
+#     docker-compose -f config/docker/docker-compose.simple.yaml up
+#
+# This script is just a wrapper for that command.
+
+install_docker_compose() {
+  if docker-compose version > /dev/null; then
+    return
+  fi
+
+  if apt --version; then
+    sudo apt install docker docker-compose
+  elif dnf --version; then
+    sudo dnf install docker docker-compose
+  elif pacman --version; then
+    sudo pacman -Sy docker docker-compose
+  else
+    echo "Error: Couldn't automatically install docker-compose. Install docker-compose manually."
+    exit 1
+  fi
+}
+
+start_docker() {
+  if docker version > /dev/null; then
+    return
+  fi
+
+  sudo systemctl start docker
+}
+
+docker_compose() {
+  COMPOSE_FILE="$(dirname "$(realpath "$0")")/../config/docker/docker-compose.simple.yaml"
+  docker-compose -f "$COMPOSE_FILE" "$@"
+}
+
+install_docker_compose
+start_docker
+docker_compose "${@:-up}"