Dockerfile.build

FROM rust:1.87-bookworm

# Install cross-compilation toolchains
#   - x86_64-unknown-linux-gnu    : native (no extra packages needed)
#   - aarch64-unknown-linux-gnu   : gcc-aarch64-linux-gnu
#   - x86_64-pc-windows-gnu       : gcc-mingw-w64-x86-64
RUN apt-get update && apt-get install -y --no-install-recommends \
        gcc-aarch64-linux-gnu \
        gcc-mingw-w64-x86-64 \
    && rm -rf /var/lib/apt/lists/*

# Add Rust cross-compilation targets
RUN rustup target add \
        aarch64-unknown-linux-gnu \
        x86_64-pc-windows-gnu

# Configure Cargo linkers for each cross target
RUN mkdir -p /root/.cargo && printf '\
[target.aarch64-unknown-linux-gnu]\n\
linker = "aarch64-linux-gnu-gcc"\n\
\n\
[target.x86_64-pc-windows-gnu]\n\
linker = "x86_64-w64-mingw32-gcc"\n\
' >> /root/.cargo/config.toml

WORKDIR /src
COPY . .

# Embedded build script:
#   1. Read APP_NAME and VERSION from Cargo.toml
#   2. Build for each target
#   3. Copy artefacts to /output (volume-mounted from host)
CMD set -e && \
    APP_NAME=$(grep '^name' Cargo.toml | head -1 | sed 's/.*"\(.*\)"/\1/') && \
    VERSION=$(grep '^version' Cargo.toml | head -1 | sed 's/.*"\(.*\)"/\1/') && \
    echo "==> Building ${APP_NAME} v${VERSION}" && \
    \
    echo "--- [1/3] x86_64-unknown-linux-gnu ---" && \
    cargo build --release --target x86_64-unknown-linux-gnu && \
    \
    echo "--- [2/3] aarch64-unknown-linux-gnu ---" && \
    CC=aarch64-linux-gnu-gcc \
    cargo build --release --target aarch64-unknown-linux-gnu && \
    \
    echo "--- [3/3] x86_64-pc-windows-gnu ---" && \
    CC=x86_64-w64-mingw32-gcc \
    cargo build --release --target x86_64-pc-windows-gnu && \
    \
    mkdir -p /output && \
    cp target/x86_64-unknown-linux-gnu/release/${APP_NAME}   /output/${APP_NAME}-${VERSION}-linux-amd64 && \
    cp target/aarch64-unknown-linux-gnu/release/${APP_NAME}  /output/${APP_NAME}-${VERSION}-linux-arm64 && \
    cp target/x86_64-pc-windows-gnu/release/${APP_NAME}.exe  /output/${APP_NAME}-${VERSION}-windows-amd64.exe && \
    \
    echo "==> Build complete. Artefacts in /output:" && \
    ls -lh /output/