feat: Zephyr 2.3.0 & SDK 0.11.4

Foundation version of GitHub workflow and Dockerfile.

Based on:
https://docs.zephyrproject.org/2.3.0/getting_started/index.html
https://docs.zephyrproject.org/2.3.0/getting_started/installation_linux.html#install-requirements-and-dependencies
+ SDK 0.11.4

Dockerfile

@@ -0,0 +1,86 @@
+FROM debian:stable-20201117-slim AS common
+
+CMD ["/bin/bash"]
+
+ARG REPOSITORY_URL=https://github.com/innovaker/zmk-docker
+LABEL org.opencontainers.image.source ${REPOSITORY_URL}
+
+ARG ZEPHYR_VERSION
+ENV ZEPHYR_VERSION=${ZEPHYR_VERSION}
+RUN \
+  apt-get -y update \
+  && apt-get -y install --no-install-recommends \
+  ccache \
+  cmake \
+  file \
+  gcc \
+  gcc-multilib \
+  git \
+  gperf \
+  make \
+  ninja-build \
+  python3 \
+  python3-pip \
+  python3-setuptools \
+  python3-wheel \
+  && pip3 install \
+  -r https://raw.githubusercontent.com/zephyrproject-rtos/zephyr/v${ZEPHYR_VERSION}/scripts/requirements-base.txt \
+  && apt-get remove -y --purge \
+  python3-pip \
+  python3-setuptools \
+  python3-wheel \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+#------------------------------------------------------------------------------
+
+FROM common AS dev-generic
+
+RUN \
+  apt-get -y update \
+  && apt-get -y install --no-install-recommends \
+  g++-multilib \
+  libsdl2-dev \
+  python3 \
+  python3-dev \
+  python3-pip \
+  python3-setuptools \
+  python3-tk \
+  python3-wheel \
+  wget \
+  xz-utils \
+  && pip3 install \
+  -r https://raw.githubusercontent.com/zephyrproject-rtos/zephyr/v${ZEPHYR_VERSION}/scripts/requirements-build-test.txt \
+  -r https://raw.githubusercontent.com/zephyrproject-rtos/zephyr/v${ZEPHYR_VERSION}/scripts/requirements-run-test.txt \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+#------------------------------------------------------------------------------
+
+FROM common AS build
+
+ARG ARCHITECTURE
+ARG ZEPHYR_SDK_VERSION
+ARG ZEPHYR_SDK_SETUP_FILENAME=zephyr-toolchain-${ARCHITECTURE}-${ZEPHYR_SDK_VERSION}-setup.run
+ARG ZEPHYR_SDK_INSTALL_DIR=/opt/zephyr-sdk-${ZEPHYR_SDK_VERSION}
+RUN \
+  apt-get -y update \
+  && apt-get -y install --no-install-recommends \
+  bzip2 \
+  wget \
+  xz-utils \
+  && wget -q "https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v${ZEPHYR_SDK_VERSION}/${ZEPHYR_SDK_SETUP_FILENAME}" \
+  && sh ${ZEPHYR_SDK_SETUP_FILENAME} --quiet -- -d ${ZEPHYR_SDK_INSTALL_DIR} \
+  && rm ${ZEPHYR_SDK_SETUP_FILENAME} \
+  && apt-get remove -y --purge \
+  bzip2 \
+  wget \
+  xz-utils \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+#------------------------------------------------------------------------------
+
+FROM dev-generic AS dev
+
+COPY --from=build ${ZEPHYR_SDK_INSTALL_DIR} ${ZEPHYR_SDK_INSTALL_DIR}