#!/bin/sh
set -eu

VERSION="${1:?usage: build_iperf3.sh <version> [output_dir]}"
OUTPUT_DIR="${2:-$PWD/dist}"
WORKDIR="${TMPDIR:-/tmp}/iperf3-build-${VERSION}"
PREFIX_NAME="iperf3-${VERSION}-linux-amd64-musl-static"

rm -rf "$WORKDIR"
mkdir -p "$WORKDIR" "$OUTPUT_DIR"
cd "$WORKDIR"

apk add --no-cache \
  bash \
  build-base \
  curl \
  file \
  linux-headers \
  openssl-dev \
  python3 \
  tar \
  xz \
  zlib-dev

curl -fsSLO "https://downloads.es.net/pub/iperf/iperf-${VERSION}.tar.gz"
tar -xzf "iperf-${VERSION}.tar.gz"
cd "iperf-${VERSION}"

export CFLAGS="-O2 -fno-pie"
export CPPFLAGS=""
export LDFLAGS="-no-pie"

./configure \
  --disable-shared \
  --enable-static \
  --enable-static-bin \
  --without-sctp

make -j"$(getconf _NPROCESSORS_ONLN || echo 2)"
strip src/iperf3

install -m 0755 src/iperf3 "$OUTPUT_DIR/$PREFIX_NAME"
(
  cd "$OUTPUT_DIR"
  tar -czf "${PREFIX_NAME}.tar.gz" "$PREFIX_NAME"
  sha256sum "$PREFIX_NAME" "${PREFIX_NAME}.tar.gz" > "${PREFIX_NAME}.sha256"
)

file "$OUTPUT_DIR/$PREFIX_NAME"
ldd "$OUTPUT_DIR/$PREFIX_NAME" || true

if file "$OUTPUT_DIR/$PREFIX_NAME" | grep -qi 'dynamically linked'; then
  echo "error: output binary is still dynamically linked" >&2
  exit 1
fi