build: add `syntax` parser directive to Dockerfile
@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
FROM docker.io/nginxproxy/docker-gen:0.14.5 AS docker-gen
FROM docker.io/nginxproxy/forego:0.18.2 AS forego
FROM docker.io/nginxproxy/docker-gen:0.14.5-debian AS docker-gen
FROM docker.io/nginxproxy/forego:0.18.2-debian AS forego
# Docker Image running one (or multiple) webservers listening on all given ports from WEB_PORTS environment variable
FROM python:3-alpine