finish borg setup

roles/borg/templates/backup.service.j2

@@ -0,0 +1,6 @@
+[Unit]
+Description=Backup data using borgmatic
+
+[Service]
+ExecStart=/usr/bin/borgmatic --config {{ service_dir }}/backup.yml
+Type=oneshot

roles/borg/templates/backup.yml.j2

@@ -0,0 +1,17 @@
+location:
+    source_directories:
+        - {{ base_data_dir }}
+    repositories:
+        - ssh://root@lewis.lan/root/homeserver_backup
+retention:
+    keep_daily: 7
+    keep_weekly: 4
+    keep_monthly: 6
+storage:
+    ssh_command: ssh -i /srv/borg/id_ed25519
+    unknown_unencrypted_repo_access_is_ok: true
+hooks:
+    before_everything:
+        - systemctl stop docker docker.socket
+    after_everything:
+        - systemctl start docker