Fix finish script for s6 v3 (#115)

* Fix finish script for s6 v3

* Wrong shebang

Author: mdegat01

rootfs/etc/services.d/coredns/finish

@@ -1,8 +1,14 @@
-#!/usr/bin/execlineb -S1
+#!/usr/bin/env bashio
 # ==============================================================================
 # Take down the S6 supervision tree when CoreDNS fails
+# s6-overlay docs: https://github.com/just-containers/s6-overlay
 # ==============================================================================
-if { s6-test ${1} -ne 0 }
-if { s6-test ${1} -ne 256 }
+declare APP_EXIT_CODE=${1}
 
-s6-svscanctl -t /var/run/s6/services
+if [[ "${APP_EXIT_CODE}" -ne 0 ]] && [[ "${APP_EXIT_CODE}" -ne 256 ]]; then
+  bashio::log.warning "Halt DNS plug-in with exit code ${APP_EXIT_CODE}"
+  echo "${APP_EXIT_CODE}" > /run/s6-linux-init-container-results/exitcode
+  exec /run/s6/basedir/bin/halt
+fi
+
+bashio::log.info "Service restart after closing"