Adding logic to remove need for makefile with example bash build script

Dockerfile.amd64

@@ -1,10 +1,10 @@
-# Built with arch: amd64 flavor: lxde image: ubuntu:20.04
+# Built with arch: amd64 flavor: lxde image: ${DOCKER_BASE_IMAGE}
 #
 ################################################################################
 # base system
 ################################################################################
-
+ARG DOCKER_BASE_IMAGE
-FROM ubuntu:20.04 as system
+FROM ${DOCKER_BASE_IMAGE} as system
 
 
 
@@ -82,7 +82,7 @@ RUN apt-get update \
 ################################################################################
 # builder
 ################################################################################
-FROM ubuntu:20.04 as builder
+FROM ${DOCKER_BASE_IMAGE} as builder
 
 
 RUN sed -i 's#http://archive.ubuntu.com/ubuntu/#mirror://mirrors.ubuntu.com/mirrors.txt#' /etc/apt/sources.list;

Dockerfile.arm64

@@ -5,9 +5,11 @@
 ################################################################################
 
 # qemu helper for arm build
-FROM ubuntu:20.04 as amd64
+ARG DOCKER_BASE_IMAGE
+
+FROM ${DOCKER_BASE_IMAGE} as amd64
 RUN apt update && apt install -y qemu-user-static
-FROM arm64v8/ubuntu:20.04 as system
+FROM arm64v8/${DOCKER_BASE_IMAGE} as system
 COPY --from=amd64 /usr/bin/qemu-aarch64-static /usr/bin/
 
 
@@ -79,7 +81,7 @@ RUN apt-get update \
 ################################################################################
 # builder
 ################################################################################
-FROM ubuntu:20.04 as builder
+FROM ${DOCKER_BASE_IMAGE} as builder
 
 
 RUN sed -i 's#http://archive.ubuntu.com/ubuntu/#mirror://mirrors.ubuntu.com/mirrors.txt#' /etc/apt/sources.list;

Dockerfile.armhf

@@ -1,13 +1,15 @@
-# Built with arch: armhf flavor: lxde image: ubuntu:18.04
+# Built with arch: armhf flavor: lxde image: ${DOCKER_BASE_IMAGE}
 #
 ################################################################################
 # base system
 ################################################################################
 
+ARG DOCKER_BASE_IMAGE
+
 # qemu helper for arm build
-FROM ubuntu:18.04 as amd64
+FROM ${DOCKER_BASE_IMAGE} as amd64
 RUN apt update && apt install -y qemu-user-static
-FROM arm32v7/ubuntu:18.04 as system
+FROM arm32v7/${DOCKER_BASE_IMAGE} as system
 COPY --from=amd64 /usr/bin/qemu-arm-static /usr/bin/
 
 
@@ -75,7 +77,7 @@ RUN apt-get update \
 ################################################################################
 # builder
 ################################################################################
-FROM ubuntu:18.04 as builder
+FROM ${DOCKER_BASE_IMAGE} as builder
 
 
 RUN sed -i 's#http://archive.ubuntu.com/ubuntu/#mirror://mirrors.ubuntu.com/mirrors.txt#' /etc/apt/sources.list;

build.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+#Ensure nothing happens outside the directory this script is ran from
+cd "$(dirname "$0")"
+SCRIPT_DIRECTORY=$(pwd)
+
+ARCHITECTURE=""
+case $(uname -m) in
+    i386)   ARCHITECTURE="386" ;;
+    i686)   ARCHITECTURE="386" ;;
+    x86_64) ARCHITECTURE="amd64" ;;
+    arm)    dpkg --print-ARCHITECTURE | grep -q "arm64" && ARCHITECTURE="arm64" || ARCHITECTURE="arm" ;;
+esac
+
+echo "[INFO] Processor Architecture Detected as $ARCHITECTURE"
+
+DOCKER_BASE_IMAGE="ubuntu:18.04"
+DOCKER_FINAL_IMAGE_TAG="dorowu/ubuntu-desktop-lxde-vnc:bionic"
+
+# Comment or Uncomment as needed to build the appropriate final image
+# DOCKER_BASE_IMAGE="ubuntu:20.04"
+# DOCKER_FINAL_IMAGE_TAG="dorowu/ubuntu-desktop-lxde-vnc:latest"
+
+docker build -t "$DOCKER_FINAL_IMAGE_TAG" -f "Dockerfile.$ARCHITECTURE" \
+                                          --build-arg DOCKER_BASE_IMAGE="$DOCKER_BASE_IMAGE" \
+                                          $SCRIPT_DIRECTORY