ci: add proper cross compiling!

.woodpecker/build-and-publish.yml

@@ -3,6 +3,21 @@ when:
     branch: main
 
 steps:
+  - name: build-x86_64
+    image: rust:bookworm
+    commands:
+      - cargo build --release
+  - name: build-arm64
+    image: rust:bookworm
+    commands:
+      - dpkg --add-architecture arm64
+      - apt-get update -y && apt-get install -y crossbuild-essential-arm64 libssl-dev:arm64
+      - rustup target add aarch64-unknown-linux-gnu
+      - cargo build --target aarch64-unknown-linux-gnu --release
+    environment:
+      CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER: aarch64-linux-gnu-gcc
+      PKG_CONFIG_ALLOW_CROSS: 1
+      PKG_CONFIG_PATH: /usr/aarch64-linux-gnu/lib/pkgconfig
   - name: container-build-and-publish
     image: docker
     commands:

Dockerfile

@@ -1,16 +1,17 @@
-FROM rust:bookworm AS builder
+FROM --platform=linux/amd64 debian:12-slim AS prep
 
 WORKDIR /src
 
-COPY . .
+COPY target/release/backend backend-amd64
-
+COPY target/aarch64-unknown-linux-gnu/release/backend backend-arm64
-RUN cargo build --release
 
 FROM debian:12-slim
 
+ARG TARGETARCH
+
 RUN apt update -y && apt install libssl3 ca-certificates -y && rm -rf /var/lib/apt/lists/* /var/cache/apt/* /tmp/*
 
-COPY --from=builder /src/target/release/backend /usr/bin/gorb-backend
+COPY --from=prep /src/backend-${TARGETARCH} /usr/bin/gorb-backend
 
 COPY entrypoint.sh /usr/bin/entrypoint.sh