(feat) add watchtower for cheap container updates

README.md

@@ -2,7 +2,7 @@
 
 [![CI](https://github.com/DudeCalledBro/jellyfin/actions/workflows/ci.yml/badge.svg)](https://github.com/DudeCalledBro/jellyfin/actions/workflows/ci.yml)
 
-This repository contains my ansible and docker deployment for Jellyfin - an open-source media server.
+This repository contains the Ansible code for deploying Jellyfin using Docker.
 
 ## Prerequisites
 
@@ -23,6 +23,20 @@ This repository contains my ansible and docker deployment for Jellyfin - an open
 
 > You may have to enter a password to SSH into the target system, so you need to add `-k` after the `ansible-playbook` command.
 
+## Watchtower
+
+Watchtower is a Docker container application that automates the process of updating other Docker containers. It monitors running containers and checks for changes to their base images. When Watchtower detects that a new version of an image has been pushed to a Docker registry, it performs the following actions:
+
+- Pulls the updated image
+- Gracefully shuts down the existing container
+- Restarts the container using the new image with the same runtime options
+
+> **Side Note!** I use Watchtower for effortless updates on my systems, as I often overlook Jellyfin updates. The installation is optional.
+
+```bash
+ansible-playbook play-watchtower.yml
+```
+
 ## License
 
 Copyright © 2024 Niclas Spreng

example.config.yml

@@ -10,3 +10,6 @@ jellyfin_docker_volumes:
 # jellyfin proxy tls certificates
 jellyfin_proxy_docker_crt: ""
 jellyfin_proxy_docker_key: ""
+
+# watchtower configuration
+watchtower_docker_command: "--debug --cleanup --schedule '0 30 4 * * *'"

play-watchtower.yml

@@ -0,0 +1,8 @@
+- name: Setup Watchtower
+  hosts: all
+  pre_tasks:
+  - name: Include Variables
+    ansible.builtin.include_vars: config.yml
+
+  roles:
+  - watchtower

roles/watchtower/defaults/main.yml

@@ -0,0 +1,10 @@
+# Specifies the watchtower docker image to be used.
+watchtower_docker_image: "containrrr/watchtower:latest"
+
+# Specifies the watchtower path, owner and group.
+watchtower_docker_path: /opt/watchtower
+watchtower_docker_owner: root
+watchtower_docker_group: root
+
+# Specifies the watchtower command
+watchtower_docker_command: "--debug"

roles/watchtower/handlers/main.yml

@@ -0,0 +1,7 @@
+- name: Restart watchtower container
+  ansible.builtin.command: >-
+    docker compose --ansi never --progress plain restart
+  args:
+    chdir: "{{ watchtower_docker_path }}"
+  changed_when: true
+  listen: restart watchtower

roles/watchtower/tasks/main.yml

@@ -0,0 +1,31 @@
+- name: Create watchtower directory
+  ansible.builtin.file:
+    path: "{{ watchtower_docker_path }}"
+    owner: "{{ watchtower_docker_owner }}"
+    group: "{{ watchtower_docker_group }}"
+    state: directory
+    mode: 0755
+
+- name: Create watchtower docker compose deployment
+  ansible.builtin.template:
+    src: docker-compose.yml.j2
+    dest: "{{ watchtower_docker_path }}/docker-compose.yml"
+    owner: "{{ watchtower_docker_owner }}"
+    group: "{{ watchtower_docker_group }}"
+    trim_blocks: false
+    mode: 0644
+  notify: restart watchtower
+
+- name: Validate watchtower docker compose deployment
+  ansible.builtin.command: docker compose config --quiet
+  args:
+    chdir: "{{ watchtower_docker_path }}"
+  changed_when: false
+
+- name: Startup watchtower docker compose deployment
+  ansible.builtin.command: >-
+    docker compose --ansi never --progress plain up --detach
+  args:
+    chdir: "{{ watchtower_docker_path }}"
+  register: watchtower_container_startup
+  changed_when: "'Started' in watchtower_container_startup.stdout"

roles/watchtower/templates/docker-compose.yml.j2

@@ -0,0 +1,16 @@
+{{ ansible_managed | comment }}
+---
+services:
+  watchtower:
+    image: "{{ watchtower_docker_image }}"
+    container_name: watchtower
+    restart: unless-stopped
+    logging:
+      driver: json-file
+      options:
+        max-size: "100m"
+        max-file: "10"
+    command: "{{ watchtower_docker_command }}"
+    volumes:
+    - "/etc/localtime:/etc/localtime:ro"
+    - "/var/run/docker.sock:/var/run/docker.sock:ro"