Make backup interval configurable

defaults/main.yml

@@ -37,3 +37,4 @@ borgbackup_keep_monthly: 6
 borgbackup_keep_yearly: 0
 borgbackup_use_msmtp: true
 borgbackup_email_from: "notifications@oh14.de"
+borgbackup_interval: "hourly"

tasks/main.yml

@@ -67,7 +67,7 @@
   register: service
 
 - name: Add borgbackup timer
-  copy:
+  template:
     src: "borgbackup.timer"
     dest: "/etc/systemd/system/borgbackup.timer"
     owner: "root"

files/borgbackup.timer → templates/borgbackup.timer

@@ -2,10 +2,8 @@
 Description=borgbackup daily timer
 
 [Timer]
-# Run whenever during each hour
-# every hour
-OnCalendar=hourly
-# with a 55 minutes skew
+OnCalendar={{ borgbackup_interval }}
+# run with a 55 minutes skew
 RandomizedDelaySec=3300
 # and allow to be shifted around by at most 5 minutes by Systemd
 AccuracySec=300