# syntax=docker/dockerfile:1 # EsCaPe=` ARG ` # multi-line arg ALPINE_VERSION=alpine:3.15.4 FROM ` ${ALPINE_VERSION} as stage1 ARG ` ` # multi-line arg # and multi-line comment nginx_version="nginx:18.04@sha256:abcdef" FROM $nginx_version as stage2 FROM ` ` image5 ` #comment5 as name3 COPY ` ` --from=image12 a ` #comment5 b