Dockerfile.static

# Builds a fully static SpeedTest binary that runs on any x86_64/aarch64 Linux,
# regardless of the distro's libcurl/libxml2/glibc versions.
#
#   docker build -f Dockerfile.static -o dist .
#
# musl is used on purpose: glibc's getaddrinfo needs NSS plugins at runtime and
# cannot be linked statically in a reliable way, while musl resolves DNS in-process.

FROM alpine:3.20 AS builder

RUN apk add --no-cache \
    build-base \
    cmake \
    pkgconf \
    curl-dev curl-static \
    libxml2-dev libxml2-static \
    openssl-dev openssl-libs-static \
    zlib-static brotli-static zstd-static nghttp2-static \
    c-ares-static libidn2-static libunistring-static \
    libpsl-static libssh2-static xz-static

WORKDIR /src
COPY . .

RUN cmake -B /build -S /src -DCMAKE_BUILD_TYPE=Release -DENABLE_STATIC=ON \
    && cmake --build /build --parallel \
    && strip /build/SpeedTest

# The binary must not need a single shared library, or it is not portable.
RUN file /build/SpeedTest \
    && if ldd /build/SpeedTest 2>&1 | grep -q "Not a valid dynamic program"; then \
           echo "OK: fully static"; \
       else \
           echo "FAIL: still dynamically linked:"; ldd /build/SpeedTest; exit 1; \
       fi

# `docker build -o dist .` writes the binary straight into ./dist
FROM scratch AS export
COPY --from=builder /build/SpeedTest /SpeedTest