make dockerfile multi-arch

Author: ThatsNoMoon

Dockerfile

@@ -1,21 +1,43 @@
-FROM rust:1.61-slim-bullseye AS auditor
+FROM --platform=$BUILDPLATFORM rust:1.61-slim-bullseye AS auditor
 RUN apt-get update && \
     apt-get install -y --no-install-recommends pkg-config=0.29.2-1 libssl-dev=1.1.1n-1+deb11u1 && \
     USER=root cargo new --bin highlights && \
     cargo install cargo-audit
 COPY ["Cargo.*", "./"]
 RUN cargo audit -D unsound -D yanked
 
-FROM rust:1.61-alpine3.15 AS builder
+FROM --platform=$BUILDPLATFORM rust:1.61-alpine3.15 AS builder
 RUN apk add --no-cache --update musl-dev=1.2.2-r7 && \
     USER=root cargo new --bin highlights
+
+ARG RUSTTARGET
+ARG MUSLHOST
+ARG MUSLTARGET
+RUN if [[ ! -z "$RUSTTARGET" ]]; then \
+        rustup target add $RUSTTARGET && \
+        wget https://more.musl.cc/10.2.1/$MUSLHOST/$MUSLTARGET-cross.tgz && \
+        tar xzf $MUSLTARGET-cross.tgz; \
+    fi
+
 WORKDIR /highlights
 COPY ["Cargo.toml", "Cargo.lock", "./"]
-RUN cargo build --release && \
-    rm src/*.rs && \
-    rm ./target/release/deps/highlights*
+RUN cargo fetch ${RUSTTARGET:+--target $RUSTTARGET}
+RUN if [[ ! -z "$RUSTTARGET" ]]; then \
+        export CC=/$MUSLTARGET-cross/bin/$MUSLTARGET-gcc; \
+        mkdir .cargo && \
+        echo "[target.$RUSTTARGET]" > .cargo/config.toml && \
+        echo "linker = \"$CC\"" >> .cargo/config.toml; \
+    fi; \
+    cargo build --release ${RUSTTARGET:+--target $RUSTTARGET} && \
+    rm src/main.rs target/$RUSTTARGET/release/deps/highlights*
 COPY ["src", "./src"]
-RUN cargo build --release
+RUN if [[ ! -z "$RUSTTARGET" ]]; then \
+        export CC=/$MUSLTARGET-cross/bin/$MUSLTARGET-gcc; \
+    fi; \
+    cargo build --release ${RUSTTARGET:+--target $RUSTTARGET} && \
+    if [[ ! -z "$RUSTTARGET" ]]; then \
+        mv target/$RUSTTARGET/release/highlights target/release/highlights; \
+    fi
 
 FROM alpine:3.15.0
 RUN apk add --no-cache --update tini=0.19.0-r0 && \

README.md

@@ -18,6 +18,13 @@ For self-hosters, highlights includes:
 ## Docker
 You can find a Dockerfile in this repository, or use [`thatsnomoon/highlights`](https://hub.docker.com/r/thatsnomoon/highlights). Also provided is a `docker-compose.yml` that will organize Highlights, a Jaeger agent, collector, and query server, and Cassandra, and should set up Cassandra to accept Jaeger logs.
 
+### AArch64, other alternate architectures
+
+The Dockerfile provided supports building to any architecture supported by both Rust and [musl.cc](https://musl.cc). I build `thatsnomoon/highlights` for AArch64 alongside x86_64; if you need a different architecture, use `docker buildx build` with `--platform=linux/<architecture>` and provide appropriate values for the following build args:
+- `--build-arg RUSTTARGET=<rust target triple>` (ex: `aarch64-unknown-linux-musl`)
+- `--build-arg MUSLHOST=<musl host triple>` (ex: `x86_64-linux-musl`; see [supported musl.cc hosts](https://more.musl.cc/10.2.1))
+- `--build-arg MUSLTARGET=<musl target triple>` (ex: `aarch64-linux-musl`; for x86_64, see [supported musl.cc targets here](https://more.musl.cc/10.2.1/x86_64-linux-musl))
+
 ## Download
 You can find downloads for 64 bit Windows and Linux, as well as 64 bit Linux ARM (for e.g. Raspberry Pi) on [the releases page](https://github.com/ThatsNoMoon/highlights/releases/).