Initial multi-arch image commit (#86)

Adding multi-arch image support for `arm64` and `amd64`. This uses dockers new `buildx` feature, to enable further architectures more work will be required to update the `runner/Dockerfile` file to pull architecture-specific releases.

The Makefile targets really should only be used for local testing and not for release, additional work to appropriately tag the release images may need to be added but for now, I've not added that logic.

Fixes: #86 

Signed-off-by: Michael Fornaro <20387402+xUnholy@users.noreply.github.com>

runner/Dockerfile

@@ -1,7 +1,8 @@
 FROM ubuntu:18.04
 
-ARG RUNNER_VERSION
-ARG DOCKER_VERSION
+ARG TARGETPLATFORM
+ARG RUNNER_VERSION=2.272.0
+ARG DOCKER_VERSION=19.03.12
 
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt update -y \
@@ -9,46 +10,55 @@ RUN apt update -y \
   && add-apt-repository -y ppa:git-core/ppa \
   && apt update -y \
   && apt install -y --no-install-recommends \
-     build-essential \
-     curl \
-     ca-certificates \
-     dnsutils \
-     ftp \
-     git \
-     iproute2 \
-     iputils-ping \
-     jq \
-     libunwind8 \
-     locales \
-     netcat \
-     openssh-client \
-     parallel \
-     rsync \
-     shellcheck \
-     sudo \
-     telnet \
-     time \
-     tzdata \
-     unzip \
-     upx \
-     wget \
-     zip \
-     zstd \
+  build-essential \
+  curl \
+  ca-certificates \
+  dnsutils \
+  ftp \
+  git \
+  iproute2 \
+  iputils-ping \
+  jq \
+  libunwind8 \
+  locales \
+  netcat \
+  openssh-client \
+  parallel \
+  rsync \
+  shellcheck \
+  sudo \
+  telnet \
+  time \
+  tzdata \
+  unzip \
+  upx \
+  wget \
+  zip \
+  zstd \
   && rm -rf /var/lib/apt/lists/*
 
-RUN curl -L -o docker.tgz https://download.docker.com/linux/static/stable/x86_64/docker-${DOCKER_VERSION}.tgz \
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+  && curl -L -o /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_${ARCH} \
+  && chmod +x /usr/local/bin/dumb-init
+
+# Docker download supports arm64 as aarch64 & amd64 as x86_64
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+  && if [ "$ARCH" = "arm64" ]; then export ARCH=aarch64 ; fi \
+  && if [ "$ARCH" = "amd64" ]; then export ARCH=x86_64 ; fi \
+  && curl -L -o docker.tgz https://download.docker.com/linux/static/stable/${ARCH}/docker-${DOCKER_VERSION}.tgz \
   && tar zxvf docker.tgz \
   && install -o root -g root -m 755 docker/docker /usr/local/bin/docker \
   && rm -rf docker docker.tgz \
-  && curl -L -o /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_amd64 \
-  && chmod +x /usr/local/bin/dumb-init \
   && adduser --disabled-password --gecos "" --uid 1000 runner \
   && usermod -aG sudo runner \
   && echo "%sudo   ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers
 
-RUN mkdir -p /runner \
+# Runner download supports amd64 as x64
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+  && if [ "$ARCH" = "amd64" ]; then export ARCH=x64 ; fi \
+  && mkdir -p /runner \
   && cd /runner \
-  && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz \
+  && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-${ARCH}-${RUNNER_VERSION}.tar.gz \
   && tar xzf ./runner.tar.gz \
   && rm runner.tar.gz \
   && ./bin/installdependencies.sh \

runner/Makefile

@@ -4,9 +4,38 @@ TAG ?= latest
 RUNNER_VERSION ?= 2.273.4
 DOCKER_VERSION ?= 19.03.12
 
+# default list of platforms for which multiarch image is built
+ifeq (${PLATFORMS}, )
+	export PLATFORMS="linux/amd64,linux/arm64"
+endif
+
+# if IMG_RESULT is unspecified, by default the image will be pushed to registry
+ifeq (${IMG_RESULT}, load)
+	export PUSH_ARG="--load"
+    # if load is specified, image will be built only for the build machine architecture.
+    export PLATFORMS="local"
+else ifeq (${IMG_RESULT}, cache)
+	# if cache is specified, image will only be available in the build cache, it won't be pushed or loaded
+	# therefore no PUSH_ARG will be specified
+else
+	export PUSH_ARG="--push"
+endif
+
 docker-build:
 	docker build --build-arg RUNNER_VERSION=${RUNNER_VERSION} --build-arg DOCKER_VERSION=${DOCKER_VERSION} -t ${NAME}:${TAG} -t ${NAME}:v${RUNNER_VERSION} .
 
 docker-push:
 	docker push ${NAME}:${TAG}
 	docker push ${NAME}:v${RUNNER_VERSION}
+
+docker-buildx:
+	export DOCKER_CLI_EXPERIMENTAL=enabled
+	@if ! docker buildx ls | grep -q container-builder; then\
+		docker buildx create --platform ${PLATFORMS} --name container-builder --use;\
+	fi
+	docker buildx build --platform ${PLATFORMS} \
+		--build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+		--build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+		-t "${NAME}:latest" \
+		-f Dockerfile \
+		. ${PUSH_ARG}