build: Faster and streamlined cross builds (#70)

Switches to cross-building in a container matching the native host
architecture. For now, this assumes arm64 -> amd64, but will be easy to
extend also for amd64 -> arm64 cross builds.

Author: jan-auer

.github/workflows/build.yml

@@ -48,7 +48,7 @@ jobs:
 
       - name: Build Binary
         run: |
-          cargo build --release --target=${{ matrix.target }} --bin objectstore
+          cargo build --release --locked --target=${{ matrix.target }} --bin objectstore
           cp target/${{ matrix.target }}/release/objectstore ./objectstore
 
       - name: Set up Docker Buildx

Dockerfile

@@ -1,10 +1,10 @@
 FROM gcr.io/distroless/cc-debian12:nonroot
 
-ENV FSS_PATH="/data"
-
-# Copy the pre-built binary
-COPY objectstore /bin/objectstore
+ARG BINARY=objectstore
+COPY ${BINARY} /bin/application
 
 VOLUME ["/data"]
-ENTRYPOINT ["/bin/objectstore"]
+ENV FSS_PATH="/data"
+
+ENTRYPOINT ["/bin/application"]
 EXPOSE 8888

Dockerfile.cross

@@ -0,0 +1,20 @@
+# Dockerfile for cross-compiling from aarch64 (host) to amd64 (target)
+FROM rust:slim-bookworm
+
+RUN dpkg --add-architecture amd64 \
+    && apt-get update -qq \
+    && apt-get upgrade -y \
+    && apt-get install -y --no-install-recommends protobuf-compiler libprotobuf-dev pkg-config libssl-dev:amd64 gcc-x86-64-linux-gnu g++-x86-64-linux-gnu \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN rustup target add x86_64-unknown-linux-gnu
+
+ENV CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_LINKER=x86_64-linux-gnu-gcc
+ENV CC=x86_64-linux-gnu-gcc
+ENV PKG_CONFIG_ALLOW_CROSS=1
+ENV OPENSSL_LIB_DIR=/usr/lib/x86_64-linux-gnu
+ENV OPENSSL_INCLUDE_DIR=/usr/include
+
+WORKDIR /workspace
+ENTRYPOINT ["cargo", "build", "--release", "--target=x86_64-unknown-linux-gnu"]
+CMD ["--bin", "objectstore"]

Dockerfile.stresstest

@@ -30,11 +30,39 @@ Ensure `protoc` and the latest stable Rust toolchain are installed on your
 machine. A release build can be created with:
 
 ```sh
-cargo build --release
+cargo build --release --locked
 ```
 
 The server binary will be located at `target/release/objectstore`.
 
+### Docker Container
+
+To build the Docker container, first build the release binary, then build the
+container:
+
+```sh
+docker build -f Dockerfile target/release/
+```
+
+The last argument must be the path to the directory that contains the
+`objectstore` binary.
+
+### Cross-building for AMD64 from ARM64
+
+We have utilities to cross-build an AMD64 container from an ARM64 host, such as
+a macOS machine running on Apple Silicon. To do this, run:
+
+```sh
+scripts/build-cross.sh
+```
+
+This script will take care of the entire cross-compilation build process inside
+an ARM-based Docker container and use the project's `target/` directory for
+caching and build output. The build results in two artifacts:
+
+- The binary at `target/x86_64-unknown-linux-gnu/release/objectstore`
+- The docker container, tagged with `objectstore:latest`
+
 ## Development
 
 ### Environment Setup

README.md

@@ -0,0 +1,31 @@
+#!/bin/bash
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+BINARY=${1:-objectstore}
+case "$BINARY" in
+    objectstore) PACKAGE="objectstore-server" ;;
+    *) PACKAGE="$BINARY" ;;
+esac
+
+docker build \
+    --platform linux/arm64 \
+    -f Dockerfile.cross \
+    -t objectstore-build \
+    .
+
+docker run --rm \
+    --platform linux/arm64 \
+    -v "$(pwd)":/workspace \
+    -v "$HOME/.cargo/registry":/usr/local/cargo/registry \
+    -v "$HOME/.cargo/git":/usr/local/cargo/git \
+    objectstore-build \
+    -p "$PACKAGE"
+
+docker build \
+    --platform linux/amd64 \
+    -f Dockerfile \
+    --build-arg BINARY="$BINARY" \
+    -t "$BINARY:latest" \
+    "target/x86_64-unknown-linux-gnu/release/"