Set up a recovery script for MC servers

this shit happens to goddamn often-

roles/minecraft/tasks/main.yml

@@ -47,6 +47,14 @@
         dest: "/var/minecraft/{{ mcname }}/modpack.zip"
         url: "{{ mczip }}"
       register: get_mcpack
+    - name: Template out scripts
+      template:
+        src: "{{ item.src }}"
+        dest: "/var/minecraft/{{ mcname }}/{{ item.dest }}"
+        mode: "{{ item.mode }}"
+      loop:
+        - { src: "install.sh", dest: "install.sh", mode: "0755" }
+        - { src: "recover.sh", dest: "recover.sh", mode: "0755" }
     - name: Install modpack
       block:
         - name: Disable service
@@ -71,10 +79,6 @@
             remote_src: yes
             dest: "/var/minecraft/{{ mcname }}"
           notify: "restart minecraft {{ mcname }}"
-        - name: Template out install script
-          template:
-            src: "install.sh"
-            dest: "/var/minecraft/{{ mcname }}/install.sh"
         - name: Run install script
           command:
             chdir: "/var/minecraft/{{ mcname }}"
@@ -123,6 +127,19 @@
             state: link
           when: not stat_mcroot_newjar.stat.exists
       when: not stat_mcroot_forgejar.stat.exists
+    - name: Check for world
+      stat:
+        path: "/var/minecraft/{{ mcname }}/world"
+      register: stat_mcroot_world
+    - name: Recover world, if available
+      block:
+        - name: Run recover script
+          command:
+            chdir: "/var/minecraft/{{ mcname }}"
+            argv:
+              - bash
+              - "./recover.sh"
+          notify: "restart minecraft {{ mcname }}"
     - name: Configure server
       block:
         - name: Template out server.properties

roles/minecraft/templates/recover.sh

@@ -0,0 +1,42 @@
+#! /bin/sh
+#
+# recover.sh
+# Recover a Minecraft world save from our S3 bucket
+# Copyright (C) 2020 Vintage Salt <rehashedsalt@cock.li>
+#
+# Distributed under terms of the MIT license.
+#
+
+set -e
+
+# Get to our magic dir
+export MINECRAFT_DIR="/var/minecraft/{{ mcname }}"
+cd "$MINECRAFT_DIR" || exit 50
+
+# If the world directory exists, we need to ensure that we don't clobber it
+if [ -d "world" ]; then
+	echo "Backing up current world"
+	tar czf "recover-world-$(date -Iseconds).tar.gz" world --remove-files
+fi
+# If it STILL exists, then we have a problem
+if [ -d "world" ]; then
+	echo "World was found to exist after tarring; bailing"
+	exit 51
+fi
+
+# Get our latest good backup
+backup="$(aws s3 ls "s3://{{ aws_backup_bucket }}/{{ mcname }}/" | tail -n 1 | awk '{print $4}')"
+echo "Restoring backup: $backup"
+aws s3 cp "s3://{{ aws_backup_bucket }}/{{ mcname }}/$backup" world.tgz
+# Decompress it
+tar xzf world.tgz
+# Find the world
+worlddir="$(find . -type d -name "world" | head -n 1)"
+# Move it in place
+mv "$worlddir" .
+# Verify our work
+if [ -f "world/level.dat" ]; then
+	echo "Recovered from backup: $backup"
+else
+	echo "Failed to recover from backup: $backup"
+fi

roles/terraria/tasks/main.yml

@@ -7,6 +7,13 @@
       apt:
         name:
           - mono-complete
+    - name: Disable bundled services
+      systemd:
+        name: "{{ item }}"
+        enabled: no
+        state: stopped
+      loop:
+        - "mono-xsp4"
     - name: Assure terraria admin group
       group:
         name: ter-admin