bicep/{postgres,mysql}: split config into several files

hosts/bicep/services/postgresql/backup.nix

@@ -0,0 +1,27 @@
+{ config, lib, ... }:
+let
+  cfg = config.services.postgresql;
+in
+{
+  services.postgresqlBackup = lib.mkIf cfg.enable {
+    enable = true;
+    location = "/var/lib/postgres-backups";
+    backupAll = true;
+  };
+
+  services.rsync-pull-targets = lib.mkIf cfg.enable {
+    enable = true;
+    locations.${config.services.postgresqlBackup.location} = {
+      user = "root";
+      rrsyncArgs.ro = true;
+      authorizedKeysAttrs = [
+        "restrict"
+        "no-agent-forwarding"
+        "no-port-forwarding"
+        "no-pty"
+        "no-X11-forwarding"
+      ];
+      publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGvO7QX7QmwSiGLXEsaxPIOpAqnJP3M+qqQRe5dzf8gJ postgresql rsync backup";
+    };
+  };
+}