feat(backup): backup server to borgbase daily

borgbackup.nix

@@ -0,0 +1,30 @@
+{
+  services.borgbackup.jobs."borgbase" = {
+    paths = [
+      "/var/backup"
+      "/var/lib/sourcehut"
+      "/etc/nixos"
+      "/root"
+      "/home"
+    ];
+    exclude = [
+      "**/*cache"
+      "**/*Cache"
+      "**/*trash"
+      "**/*Trash"
+      "/home/*/.local"
+      "**/target"
+      "**/result"
+    ];
+    repo = "foy40rzb@foy40rzb.repo.borgbase.com:repo";
+    encryption = {
+      mode = "repokey-blake2";
+      passCommand = "cat /root/borgbackup/passphrase";
+    };
+    environment.BORG_RSH = "ssh -i /root/borgbackup/ssh_key";
+    compression = "auto,lzma";
+    startAt = "daily";
+    # also start if the starttime was missed
+    persistentTimer = true;
+  };
+}

configuration.nix

@@ -6,6 +6,7 @@ in
   imports = [
     ./hardware-configuration.nix
     ./firewall.nix
+    ./borgbackup.nix
 
     (import ./acme.nix { inherit base-domain; })
     (import ./nginx.nix { inherit base-domain; })