__nginx_vhost: make configuration reload more robust

type/__nginx_vhost/gencode-remote

@@ -1,21 +1,29 @@
 #!/bin/sh
 
 os="$(cat "${__global:?}"/explorer/os)"
+init=$(cat "$__global/explorer/init")
+nginx_confdir="/etc/nginx"
 
-case "$os" in
-	alpine)
-		reload_hook="service nginx --ifstopped start;\
-			service nginx --ifstarted reload"
-		;;
-	debian|ubuntu|*)
+# The nginx service is not automatically started on alpine.
+if [ "$os" = "alpine" ]; then
+	echo "service nginx --ifstopped start"
+fi
+
+if grep -qE "^__file$nginx_confdir" "${__messages_in:?}"; then
+	case "$init" in
+		systemd)
 			reload_hook="systemctl reload-or-restart nginx"
 			;;
+		busybox-init+openrc)
+			reload_hook="service nginx reload"
+			;;
+		*)
+			echo "Unknown init $init." >&2
+			exit 1
+			;;
 	esac
 
-# Check configuration and reload if valid.
-# TODO: only check if configuration was changed (= listen for __file's
-# messages).
-cat << EOF
+	cat <<- EOF
 	if nginx -t; then
 	  $reload_hook
 	else
@@ -24,3 +32,4 @@ else
 	  exit 1
 	fi
 	EOF
+fi