From 3dc0e04ab47b8d8779b6af5c924d4fa1645fa7d7 Mon Sep 17 00:00:00 2001
From: Kris Lamoureux <kris@lamoureux.io>
Date: Thu, 13 May 2021 03:35:00 -0400
Subject: [PATCH] Manage Minecraft servers with systemd

---
 dev/host_vars/minecraft.yml                   |  5 +-
 roles/.gitignore                              |  1 +
 roles/minecraft/defaults/main.yml             |  6 ++
 roles/minecraft/tasks/main.yml                | 55 +++++++++++++++++++
 roles/minecraft/templates/eula.txt.j2         |  1 +
 .../minecraft/templates/minecraft.service.j2  | 27 +++++++++
 6 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 roles/minecraft/defaults/main.yml
 create mode 100644 roles/minecraft/tasks/main.yml
 create mode 100644 roles/minecraft/templates/eula.txt.j2
 create mode 100644 roles/minecraft/templates/minecraft.service.j2

diff --git a/dev/host_vars/minecraft.yml b/dev/host_vars/minecraft.yml
index 1441cca..f057b68 100644
--- a/dev/host_vars/minecraft.yml
+++ b/dev/host_vars/minecraft.yml
@@ -3,4 +3,7 @@ allow_reboot: false
 manage_network: false
 
 # minecraft
-minecraft_eula: true
+# Agree to EULA to start service in Vagrant
+# i.e. sed -i 's/^#minecraft_eula/minecraft_eula/' ./dev/host_vars/minecraft.yml
+#minecraft_eula: true
+minecraft_sha1: 1b557e7b033b583cd9f66746b7a9ab1ec1673ced # 1.16.5
diff --git a/roles/.gitignore b/roles/.gitignore
index 4357616..9ecd153 100644
--- a/roles/.gitignore
+++ b/roles/.gitignore
@@ -7,6 +7,7 @@
 !gitea*/
 !jenkins*/
 !libvirt*/
+!minecraft*/
 !nextcloud*/
 !nginx*/
 !prometheus*/
diff --git a/roles/minecraft/defaults/main.yml b/roles/minecraft/defaults/main.yml
new file mode 100644
index 0000000..2d368f1
--- /dev/null
+++ b/roles/minecraft/defaults/main.yml
@@ -0,0 +1,6 @@
+minecraft_eula: false
+minecraft_home: "/opt/minecraft"
+minecraft_url: "https://launcher.mojang.com/v1/objects/{{ minecraft_sha1 }}/server.jar"
+minecraft_user: minecraft
+minecraft_xms: 1G
+minecraft_xmx: "{{ minecraft_xms }}"
diff --git a/roles/minecraft/tasks/main.yml b/roles/minecraft/tasks/main.yml
new file mode 100644
index 0000000..010eadd
--- /dev/null
+++ b/roles/minecraft/tasks/main.yml
@@ -0,0 +1,55 @@
+- name: Install Screen
+  apt:
+    name: screen
+    state: present
+
+- name: Install Java
+  apt:
+    name: default-jre
+    state: present
+
+- name: Create Minecraft user
+  user:
+    name: "{{ minecraft_user }}"
+    state: present
+    shell: /bin/bash
+
+- name: Create Minecraft directory
+  file:
+    path: "{{ minecraft_home }}"
+    state: directory
+    owner: "{{ minecraft_user }}"
+    group: "{{ minecraft_user }}"
+
+- name: Download Minecraft
+  get_url:
+    url: "{{ minecraft_url }}"
+    dest: "{{ minecraft_home }}/minecraft_server.jar"
+    checksum: "sha1:{{ minecraft_sha1 }}"
+    owner: "{{ minecraft_user }}"
+    group: "{{ minecraft_user }}"
+    mode: 0700
+
+- name: Deploy Minecraft systemd service
+  template:
+    src: minecraft.service.j2
+    dest: "/etc/systemd/system/minecraft.service"
+  register: minecraft_systemd
+
+- name: Answer to Mojang's EULA
+  template:
+    src: eula.txt.j2
+    dest: "{{ minecraft_home }}/eula.txt"
+    owner: "{{ minecraft_user }}"
+    group: "{{ minecraft_user }}"
+
+- name: Reload systemd manager configuration
+  systemd:
+    daemon_reload: true
+  when: minecraft_systemd.changed
+
+- name: Start Service
+  service:
+    name: minecraft
+    state: started
+  when: minecraft_eula
diff --git a/roles/minecraft/templates/eula.txt.j2 b/roles/minecraft/templates/eula.txt.j2
new file mode 100644
index 0000000..3757364
--- /dev/null
+++ b/roles/minecraft/templates/eula.txt.j2
@@ -0,0 +1 @@
+eula={{ minecraft_eula | lower }}
diff --git a/roles/minecraft/templates/minecraft.service.j2 b/roles/minecraft/templates/minecraft.service.j2
new file mode 100644
index 0000000..2879b9a
--- /dev/null
+++ b/roles/minecraft/templates/minecraft.service.j2
@@ -0,0 +1,27 @@
+[Unit]
+Description=Minecraft Server
+After=network.target
+
+[Service]
+Type=simple
+WorkingDirectory={{ minecraft_home }}
+User={{ minecraft_user }}
+Group={{ minecraft_user }}
+Restart=always
+
+ExecStart=/usr/bin/screen -DmS minecraft \
+  /usr/bin/java -Xms{{ minecraft_xms }} -Xmx{{ minecraft_xmx }} -jar minecraft_server.jar nogui
+ExecReload=/usr/bin/screen -p 0 -S minecraft -X eval 'stuff "reload"\\015'
+ExecStop=/usr/bin/screen -p 0 -S minecraft -X eval 'stuff "say SERVER SHUTDOWN IN 30 SECONDS"\015'
+ExecStop=/bin/sleep 15
+ExecStop=/usr/bin/screen -p 0 -S minecraft -X eval 'stuff "say SERVER SHUTDOWN IN 15 SECONDS"\015'
+ExecStop=/bin/sleep 10
+ExecStop=/usr/bin/screen -p 0 -S minecraft -X eval 'stuff "say SERVER SHUTDOWN IN 5 SECONDS"\015'
+ExecStop=/bin/sleep 5
+ExecStop=/usr/bin/screen -p 0 -S minecraft -X eval 'stuff "save-all"\015'
+ExecStop=/bin/sleep 1
+ExecStop=/usr/bin/screen -p 0 -S minecraft -X eval 'stuff "stop"\015'
+ExecStop=/bin/sleep 3
+
+[Install]
+WantedBy=multi-user.target