From c99eb0bdbb008c98223dcbe83f1b5160754ebb06 Mon Sep 17 00:00:00 2001
From: Ryan Hamilton <ryanehamil@outlook.com>
Date: Wed, 30 Jul 2025 05:44:16 +0000
Subject: [PATCH] Add playbooks/borgmatic-backup.yml

---
 playbooks/borgmatic-backup.yml | 57 ++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 playbooks/borgmatic-backup.yml

diff --git a/playbooks/borgmatic-backup.yml b/playbooks/borgmatic-backup.yml
new file mode 100644
index 0000000..5848ffa
--- /dev/null
+++ b/playbooks/borgmatic-backup.yml
@@ -0,0 +1,57 @@
+---
+- name: Configure Borgmatic backup with deterministic offset
+  hosts: all
+  become: true
+
+  vars:
+    borgmatic_bin: /usr/local/bin/borgmatic
+    backup_hour: 2                # Base hour to run backups
+    backup_window: 1800           # 30 min window (in seconds)
+    borgmatic_config_dir: /etc/borgmatic
+
+  tasks:
+    - name: Ensure Borg and dependencies are present
+      package:
+        name:
+          - borgbackup
+          - python3-pip
+        state: present
+
+    - name: Ensure borgmatic is installed via pip
+      pip:
+        name: borgmatic
+        executable: pip3
+
+    - name: Create borgmatic config directory
+      file:
+        path: "{{ borgmatic_config_dir }}"
+        state: directory
+        owner: root
+        group: root
+        mode: '0755'
+
+    - name: Generate deterministic backup offset
+      set_fact:
+        backup_offset: >-
+          {{ (inventory_hostname | hash('md5') | int(base=16)) % backup_window }}
+
+    - name: Split offset into minutes and seconds
+      set_fact:
+        backup_offset_minutes: "{{ backup_offset // 60 }}"
+        backup_offset_seconds: "{{ backup_offset % 60 }}"
+
+    - name: Deploy borgmatic config
+      template:
+        src: borgmatic-config.yaml.j2
+        dest: "{{ borgmatic_config_dir }}/config.yaml"
+        owner: root
+        group: root
+        mode: '0600'
+
+    - name: Create cron job for borgmatic with offset
+      cron:
+        name: "Nightly borgmatic backup"
+        user: root
+        hour: "{{ backup_hour }}"
+        minute: "{{ backup_offset_minutes }}"
+        job: "sleep {{ backup_offset_seconds }} && {{ borgmatic_bin }} --verbosity 1"