cross-compile cargo plugins

Signed-off-by: Avi Deitcher <[email protected]>

Dockerfile

@@ -1,8 +1,23 @@
 ARG RUST_VERSION=1.80.1
-FROM rust:${RUST_VERSION}-alpine3.20
-ENV TARGETS="x86_64-unknown-linux-musl aarch64-unknown-linux-musl x86_64-unknown-linux-gnu aarch64-unknown-linux-gnu riscv64gc-unknown-linux-gnu"
+
+FROM --platform=$BUILDPLATFORM tonistiigi/xx AS xx
+
+FROM --platform=$BUILDPLATFORM rust:${RUST_VERSION}-alpine3.20 AS builder
+ARG TARGETARCH
+ARG TARGETOS
+COPY --from=xx / /
+RUN echo $(xx-info march)-unknown-$(xx-info os)-musl > /etc/rustc_target
+
+RUN rustup target add $(cat /etc/rustc_target)
+# needed for cargo-chef and cargo-sbom
+RUN apk add musl-dev linux-headers make
+RUN cargo install --target=$(cat /etc/rustc_target) [email protected] [email protected]
+
+FROM rust:${RUST_VERSION}-alpine3.20 AS toolchain
+ARG TARGETS="x86_64-unknown-linux-musl aarch64-unknown-linux-musl x86_64-unknown-linux-gnu aarch64-unknown-linux-gnu riscv64gc-unknown-linux-gnu"
 RUN rustup target add ${TARGETS}
 
-# needed for cargo-chef and cargo-sbom, as well as many other compilations
+# needed for downstream compilations
 RUN apk add musl-dev linux-headers make
-RUN cargo install [email protected] [email protected]
+COPY --from=builder /usr/local/cargo/bin/cargo-chef /usr/local/cargo/bin
+COPY --from=builder /usr/local/cargo/bin/cargo-sbom /usr/local/cargo/bin