Use debconf to allow for command-line or unattended installation

debian/config

@@ -0,0 +1,21 @@
+#!/bin/sh -e
+
+. /usr/share/debconf/confmodule
+
+readonly ACTION="${1:-configure}"
+readonly VERSION="${2:-dev}"
+
+db_input "high" "dokku/web_config" || true
+db_go || true
+
+db_get "dokku/web_config"
+if [ $RET = "true" ]; then
+    exit 0
+fi
+
+db_input "high" "dokku/hostname" || true
+db_input "high" "dokku/vhost_enable" || true
+if [ "$ACTION" != "reconfigure" ]; then
+  db_input "high" "dokku/key_file" || true
+fi
+db_go || true