feat: add backup role using restic

roles/backup/templates/restic-backup.service.j2

@@ -0,0 +1,7 @@
+[Unit]
+Description=Run Restic Backup
+After=network-online.target
+
+[Service]
+Type=oneshot
+ExecStart=/usr/local/bin/restic-backup.sh

roles/backup/templates/restic-backup.sh.j2

@@ -0,0 +1,23 @@
+#!/bin/bash
+## Ansible managed
+
+## Secrets are passed via Ansible Vault variables
+export RESTIC_REPOSITORY="{{ vault_restic_repo_url }}"
+export RESTIC_PASSWORD="{{ vault_restic_password }}"
+export AWS_ACCESS_KEY_ID="{{ vault_aws_access_key }}"
+export AWS_SECRET_ACCESS_KEY="{{ vault_aws_secret_key }}"
+
+set -e
+
+echo "Starting Restic Backup at $(date)"
+
+## Run the backup (docker volumes & config files)
+restic backup \
+  /etc \
+  /opt/docker-data \
+  --exclude /opt/docker-data/tmp \
+  --cleanup-cache
+
+restic forget --prune --keep-daily 7 --keep-weekly 4 --keep-monthly 6
+
+echo "Restic backup completed at $(date)"

roles/backup/templates/restic-backup.timer.j2

@@ -0,0 +1,10 @@
+[Unit]
+Description=Run Restic Backup Daily at 4:00 AM
+
+[Timer]
+OnCalendar=*-*-* 04:00:00
+Persistent=true
+RandomizedDelaySec=1800
+
+[Install]
+WantedBy=timers.target