feat: support proper arm64 docker cross compilation using zig-cc

Dockerfile

@@ -1,31 +1,63 @@
-FROM rust:1.83-alpine3.21 AS builder
-
-ARG DI_VER=1.2.5
+# This article showed me everything I needed to get this running
+# https://dev.to/vladkens/fast-multi-arch-docker-build-for-rust-projects-an1
+FROM --platform=$BUILDPLATFORM rust:1.83-alpine3.21 AS chef
 
 WORKDIR /app
 
-RUN apk update && apk add --no-cache build-base
+ENV PKGCONFIG_SYSROOTDIR=/
+
+RUN apk update && \
+    apk add --no-cache build-base musl-dev openssl-dev zig && \
+    cargo install --locked cargo-zigbuild cargo-chef@0.1.68 && \
+    rustup target add x86_64-unknown-linux-musl aarch64-unknown-linux-musl
+
+
+FROM chef AS planner
+
+COPY . .
+
+RUN cargo chef prepare --recipe-path recipe.json
+
+
+FROM chef AS builder
 
 # Build dumb-init
-RUN wget -O - "https://github.com/Yelp/dumb-init/archive/refs/tags/v${DI_VER}.tar.gz" | tar -xzf - && \
+ARG DI_VER=1.2.5
+
+RUN mkdir -p /app/linux/arm64 /app/linux/amd64 && \
+    wget -O - "https://github.com/Yelp/dumb-init/archive/refs/tags/v${DI_VER}.tar.gz" | tar -xzf - && \
     cd "dumb-init-${DI_VER}" && \
-    make SHELL=/bin/sh && \
-    mv dumb-init .. && \
+    make CC='zig cc -target x86_64-linux-musl' SHELL=/bin/sh && \
+    ls && \
+    mv dumb-init /app/linux/amd64/dumb-init && \
+    make CC='zig cc -target aarch64-linux-musl' SHELL=/bin/sh && \
+    mv dumb-init /app/linux/arm64/dumb-init && \
     cd ..
 
-COPY Cargo.toml Cargo.lock ./
+COPY --from=planner /app/recipe.json recipe.json
 
-RUN cargo fetch --locked
+RUN cargo chef cook \
+    --recipe-path recipe.json \
+    --release --zigbuild \
+    --target x86_64-unknown-linux-musl \
+    --target aarch64-unknown-linux-musl
 
-COPY . ./
+COPY . .
 
-RUN cargo build --release --frozen
+RUN cargo zigbuild \
+    --release \
+    --target x86_64-unknown-linux-musl \
+    --target aarch64-unknown-linux-musl && \
+    cp target/aarch64-unknown-linux-musl/release/calathea /app/linux/arm64/calathea && \
+    cp target/x86_64-unknown-linux-musl/release/calathea /app/linux/amd64/calathea
 
 
 FROM alpine:3.21
 
-COPY --from=builder /app/target/release/calathea /app/calathea
-COPY --from=builder /app/dumb-init /app/dumb-init
+ARG TARGETPLATFORM
+
+COPY --from=builder /app/${TARGETPLATFORM}/calathea /app/calathea
+COPY --from=builder /app/${TARGETPLATFORM}/dumb-init /app/dumb-init
 COPY templates /app/templates
 COPY static /app/static