cross compile docker images instead of emulating

Dockerfile

@@ -1,33 +1,33 @@
-FROM rust:1-bullseye AS chef
-RUN cargo install cargo-chef 
-WORKDIR /app
+FROM --platform=${BUILDPLATFORM:-linux/amd64} tonistiigi/xx AS xx
 
-FROM chef AS planner
-COPY . .
-RUN cargo chef prepare --recipe-path recipe.json
+FROM --platform=${BUILDPLATFORM:-linux/amd64} rust:1-bullseye as builder
 
-FROM chef AS builder
+WORKDIR /app
 
-RUN apt-get update && apt-get install -y build-essential cmake clang \
-    && rm -rf /var/lib/apt/lists/*
+COPY --from=xx / /
 
-COPY --from=planner /app/recipe.json recipe.json
+# install native dependencies first so we can cache them
+RUN apt-get update && \
+    apt-get install -y build-essential cmake clang llvm g++
 
-# Build dependencies - this is the caching Docker layer!
-RUN cargo chef cook --release --recipe-path recipe.json
+ARG TARGETPLATFORM
+ENV TARGETPLATFORM=${TARGETPLATFORM:-linux/amd64}
+
+RUN xx-apt-get install -y xx-cxx-essentials g++
 
-# Build application
 COPY . .
-RUN cargo build --release --bin aero2solver
 
-FROM debian:bullseye-slim
+RUN ./build.sh
 
-RUN apt-get update && apt-get install -y libgomp1 \
-    && rm -rf /var/lib/apt/lists/*
+FROM debian:bullseye-slim AS runtime
 
 WORKDIR /app
 
+RUN apt-get update && \
+    apt-get install -y libgomp1 && \
+    rm -rf /var/lib/apt/lists/*
+
 COPY ./model/ ./model/
-COPY --from=builder /app/target/release/aero2solver ./aero2solver
+COPY --from=builder /app/target/aero2solver ./aero2solver
 
-ENTRYPOINT [ "/app/aero2solver" ]
+ENTRYPOINT [ "/app/aero2solver" ]

build.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+# set -x
+set -e
+
+# shellcheck disable=SC1091
+. xx-cargo --setup-target-triple
+RUST_TARGET_TRIPLE="$(xx-cargo --print-target-triple)"
+
+if ! xx-info is-cross; then
+    # remove these clang declarations to avoid linking errors
+    unset "CARGO_TARGET_$(echo "$RUST_TARGET_TRIPLE" | tr '[:lower:]' '[:upper:]' | tr - _)_LINKER";
+    unset "CC_$(echo "$RUST_TARGET_TRIPLE" | tr - _)"
+fi
+
+cargo build --release --bin aero2solver --target="$RUST_TARGET_TRIPLE"
+xx-verify "./target/$RUST_TARGET_TRIPLE/release/aero2solver"
+cp "./target/$RUST_TARGET_TRIPLE/release/aero2solver" "./target/aero2solver"