+d=/etc/systemd/system/radicale.service.d
+mkdir -p $d
+sudo dd of=$d/override.conf <<EOF
+[Unit]
+# this unit is configured to start and stop whenever openvpn-client@mail.service
+# does
+After=network.target
+BindsTo=$vpn_ser@mail.service
+After=$vpn_ser@mail.service
+
+[Install]
+RequiredBy=openvpn-client@mail.service
+EOF
+ser daemon-reload # not sure this is needed
+
+pi-nostart radicale