Optimize Dockerfile (#2)

* optimize Dockerfile grouping RUN statements (from 9.22GB to 7.57GB)

* optimize Dockerfile using multi-stage builds (https://learnk8s.io/blog/smaller-docker-images) (from 7.57GB to 7.37GB)

* unified env vars

* finally use single toolchains.tag.gz archive

* unfortunately using a single ENV does not seems to work

* apply suggestions from code review

Author: umbynos

Dockerfile

@@ -1,9 +1,9 @@
-FROM ubuntu:latest
+FROM ubuntu:latest as build
 
 ENV TZ=Europe/Rome
-RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
-RUN apt-get update && \
-# TODO add --no-install-recommends
+RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone && \
+    apt-get update && \
+    # TODO add --no-install-recommends
     apt-get install -y \
         build-essential \
         # Intall clang compiler used by macos
@@ -27,56 +27,63 @@ RUN apt-get update && \
     && rm -rf /var/lib/apt/lists/*
 # Install toolchains in /opt
 RUN curl downloads.arduino.cc/tools/internal/toolchains.tar.gz | tar -xz "opt"
-RUN curl downloads.arduino.cc/tools/internal/i686-ubuntu16.04-linux-gnu.tar.gz | tar -xzC /opt
-# Remove useless toolchains:
-RUN rm -r /opt/arm-rpi-4.9.3-linux-gnueabihf/
-RUN rm -r /opt/gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu/
-RUN rm -r /opt/*ubuntu12.04*
-#install proper arm toolchains
-RUN curl -L 'https://developer.arm.com/-/media/Files/downloads/gnu-a/8.3-2019.03/binrel/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf.tar.xz' | tar -xJC /opt
-RUN curl -L 'https://developer.arm.com/-/media/Files/downloads/gnu-a/8.3-2019.03/binrel/gcc-arm-8.3-2019.03-x86_64-aarch64-linux-gnu.tar.xz' | tar -xJC /opt
+    # install proper arm toolchains (already present in the toolchains.tar.gz archive)
+    # curl -L 'https://developer.arm.com/-/media/Files/downloads/gnu-a/8.3-2019.03/binrel/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf.tar.xz' | tar -xJC /opt && \
+    # curl -L 'https://developer.arm.com/-/media/Files/downloads/gnu-a/8.3-2019.03/binrel/gcc-arm-8.3-2019.03-x86_64-aarch64-linux-gnu.tar.xz' | tar -xJC /opt
 
-# install macos10.15 sdk
-COPY MacOSX10.15.sdk.tar.xz /opt/osxcross/tarballs/
-# remove old unused macos10.09 sdk because we are using 10.15 one
-RUN rm -rf /opt/osxcross/tarballs/MacOSX10.9.sdk.tar.bz2
-RUN cd /opt/osxcross; git pull; UNATTENDED=1 SDK_VERSION=10.15 ./build.sh
+RUN cd /opt/osxcross \
+    git pull \
+    # use a specific version of osxcross (it does not have tags)
+    git checkout da2c3d4ff604458a931b08b3af800c5a454136de \
+    UNATTENDED=1 SDK_VERSION=10.15 ./build.sh
 # Set toolchains paths
 # arm-linux-gnueabihf-gcc -> linux_arm
-ENV PATH=/opt/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/:$PATH
 # aarch64-linux-gnu-gcc -> linux_arm64
-ENV PATH=/opt/gcc-arm-8.3-2019.03-x86_64-aarch64-linux-gnu/bin/:$PATH
 # x86_64-ubuntu16.04-linux-gnu-gcc -> linux_amd64
-ENV PATH=/opt/x86_64-ubuntu16.04-linux-gnu-gcc/bin/:$PATH
 # i686-ubuntu16.04-linux-gnu-gcc -> linux_386
-ENV PATH=/opt/i686-ubuntu16.04-linux-gnu/bin/:$PATH
 # o64-clang -> darwin_amd64
-ENV PATH=/opt/osxcross/target/bin/:$PATH
+ENV PATH=/opt/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/:/opt/gcc-arm-8.3-2019.03-x86_64-aarch64-linux-gnu/bin/:/opt/x86_64-ubuntu16.04-linux-gnu-gcc/bin/:/opt/i686-ubuntu16.04-linux-gnu/bin/:/opt/osxcross/target/bin/:$PATH
 
-RUN mkdir -p /workdir
 WORKDIR /workdir
 
-# debug/utilities
-RUN alias ll="ls -lah"
-RUN apt-get update && apt-get install -y tree cmake-curses-gui nano && rm -rf /var/lib/apt/lists/*
-
-# Handle libusb and libudev
+# Handle libusb and libudev compilation and merging
 COPY deps/ /opt/lib/
 # compiler name is arm-linux-gnueabihf-gcc '-gcc' is added by ./configure
-ENV CROSS_COMPILE=x86_64-ubuntu16.04-linux-gnu
-RUN /opt/lib/build_libs.sh
-ENV CROSS_COMPILE=arm-linux-gnueabihf
-RUN /opt/lib/build_libs.sh
-ENV CROSS_COMPILE=aarch64-linux-gnu
-RUN /opt/lib/build_libs.sh
-ENV CROSS_COMPILE=i686-ubuntu16.04-linux-gnu
-RUN /opt/lib/build_libs.sh
-ENV CROSS_COMPILE=i686-w64-mingw32
-RUN /opt/lib/build_libs.sh
-# macos does not need eudev
-# CROSS_COMPILER is used to override the compiler 
-ENV CROSS_COMPILER=o64-clang 
-ENV CROSS_COMPILE=x86_64-apple-darwin13
-RUN /opt/lib/build_libs.sh
+RUN CROSS_COMPILE=x86_64-ubuntu16.04-linux-gnu /opt/lib/build_libs.sh && \
+    CROSS_COMPILE=arm-linux-gnueabihf /opt/lib/build_libs.sh && \
+    CROSS_COMPILE=aarch64-linux-gnu /opt/lib/build_libs.sh && \
+    CROSS_COMPILE=i686-ubuntu16.04-linux-gnu /opt/lib/build_libs.sh && \
+    CROSS_COMPILE=i686-w64-mingw32 /opt/lib/build_libs.sh && \
+    # CROSS_COMPILER is used to override the compiler 
+    CROSS_COMPILER=o64-clang CROSS_COMPILE=x86_64-apple-darwin13 /opt/lib/build_libs.sh
+
+FROM ubuntu:latest
+# Copy all the installed toolchains and compiled libs
+COPY --from=build /opt /opt
+ENV TZ=Europe/Rome
+RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone && \
+    apt-get update && \
+    apt-get install -y \
+    build-essential \
+        # Intall clang compiler used by macos
+        clang \
+        cmake \
+        dh-autoreconf \
+        git \
+        gperf \
+        # Install Windows cross-tools
+        mingw-w64 \
+        pkg-config \
+        tar \
+    && rm -rf /var/lib/apt/lists/*
+# Set toolchains paths
+# arm-linux-gnueabihf-gcc -> linux_arm
+# aarch64-linux-gnu-gcc -> linux_arm64
+# x86_64-ubuntu16.04-linux-gnu-gcc -> linux_amd64
+# i686-ubuntu16.04-linux-gnu-gcc -> linux_386
+# o64-clang -> darwin_amd64
+ENV PATH=/opt/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/:/opt/gcc-arm-8.3-2019.03-x86_64-aarch64-linux-gnu/bin/:/opt/x86_64-ubuntu16.04-linux-gnu-gcc/bin/:/opt/i686-ubuntu16.04-linux-gnu/bin/:/opt/osxcross/target/bin/:$PATH
+
+WORKDIR /workdir
 
-ENTRYPOINT ["/bin/bash"]
+ENTRYPOINT ["/bin/bash"]