From 961c64a305090ffebb7b2029991313854e235c47 Mon Sep 17 00:00:00 2001
From: Andrew Lee <andrew.lee@netapp.com>
Date: Mon, 30 Oct 2023 12:02:14 +0100
Subject: [PATCH] Add comments.

---
 crossbuild.containerfile | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/crossbuild.containerfile b/crossbuild.containerfile
index ee93369..2edb06a 100644
--- a/crossbuild.containerfile
+++ b/crossbuild.containerfile
@@ -1,7 +1,9 @@
+# Use build arguments to specify the base image and architecture
 ARG image=debian:testing
 ARG native_arch=amd64
 ARG target_arch=arm64v8
 
+# Stage 1: Build and install mini_sudo
 FROM $native_arch/$image AS mini_sudo
 WORKDIR /tmp
 COPY mini_sudo.c ./
@@ -11,6 +13,7 @@ RUN apt-get update \
     && gcc -Wall -Werror -static -o sudo mini_sudo.c \
     && install -m 6755 sudo /usr/local/bin/sudo
 
+# Stage 2: Build setup_native 
 FROM $native_arch/$image AS native
 ARG gnu_arch=aarch64
 WORKDIR /tmp
@@ -22,10 +25,15 @@ RUN apt-get update \
     && ./setup_native export $(sed 's/\$arch/'"$gnu_arch"'/' pkgs \
        | awk '{ print $NF }')
 
+# Stage 3: Final image
 FROM $target_arch/$image
 WORKDIR /tmp
+
+# Copy repository configration files for apt
 COPY debian-src.sources local-pkgs.list /etc/apt/sources.list.d/
 COPY local-pkgs /etc/apt/preferences.d/
+
+# Install packages from pkgs list and mark them as held
 COPY pkgs ./
 RUN mkdir /pkgs \
     && touch /pkgs/Packages \
@@ -34,16 +42,28 @@ RUN mkdir /pkgs \
        --no-install-recommends -y build-essential ca-certificates debhelper \
        devscripts git yq $(awk '{ print $1 }' pkgs) \
     && apt-mark hold $(awk '{ print $1 }' pkgs)
+
+# Copy the native build artifacts from the previous stage
 COPY --from=native /native /native
+
+# Copy setup_native script and execute it
 COPY setup_native ./
 RUN [ "/native/bash", "-c", "PATH=/native:$PATH ./setup_native import $(awk '{ print $1 }' pkgs)" ]
+
+# Test gcc and cleanup
 RUN gcc --print-search-dir \
     && echo 'int main() { return 0; }' > main.c \
     && gcc -o main main.c \
     && ./main \
     && find /tmp -mindepth 1 -delete
+
+# Copy the build scripts to /usr/local/bin
 COPY build_source build_indep build_archdep build /usr/local/bin/
+
+# Copy mini_sudo from stage 1
 COPY --from=mini_sudo /usr/local/bin/sudo /usr/local/bin/sudo
+
+# Create user dev and set the working directory for the user
 RUN groupadd dev && useradd -m -g dev dev
 USER dev
 RUN mkdir /home/dev/work