Dockerfile.hello

# syntax = docker/dockerfile:1.1-experimental
FROM golang:1.15-buster AS base

ENV GNU_HOST=arm-linux-gnueabi
ENV CC=$GNU_HOST-gcc

RUN apt-get update && \
  apt-get --no-install-recommends install -y autoconf \
    automake \
    build-essential \
    ca-certificates \
    cmake \
    gcc-$GNU_HOST \
    libc6-dev-armel-cross \
    git \
    gnupg \
    pkg-config && \
  rm -rf /var/lib/apt/lists/*

WORKDIR /code
ENV MSGPACK_DIR=/code/third_party/msgpack-c

RUN git clone --depth 1 --single-branch --branch c_master https://github.com/msgpack/msgpack-c.git $MSGPACK_DIR && \
  cd $MSGPACK_DIR && \
  cmake -DCMAKE_C_COMPILER=$CC \
    -DBUILD_SHARED_LIBS=OFF \
    -DMSGPACK_BUILD_EXAMPLES=OFF \
    . && \
  make -j `nproc`

COPY ./go.mod .
COPY ./go.sum .

ENV GO111MODULE=on

RUN --mount=type=cache,target=/go/pkg/mod \
  go mod download

FROM base AS builder

WORKDIR /code

ENV CGO_ENABLED=1
ENV CGO_CFLAGS="-I$MSGPACK_DIR/include"
ENV CGO_LDFLAGS="-L$MSGPACK_DIR -lmsgpackc"
ENV GOARCH=arm
ENV GOOS=linux
ENV BIN_DIR /tmp/bin

COPY . .

RUN --mount=type=cache,target=/root/.cache/ \
  --mount=type=cache,target=/go/pkg/mod,ro \
  mkdir -p $BIN_DIR && \
  go build -mod readonly \
  -o $BIN_DIR/ \
  ./cmd/...

FROM scratch
COPY --from=builder /tmp/bin /