Remove cross compilation from Dockerfile

It is really hard to make cross-compilation works nicely with musl.

Dockerfile

@@ -1,78 +1,28 @@
 # syntax=docker/dockerfile:1.4
-FROM alpine:3.19 AS alpine
-ARG TARGETPLATFORM
-
-RUN \
-    --mount=type=cache,id=$TARGETPLATFORM-alpine,target=/var/cache/apk,sharing=locked \
-    set -eux; \
-    apk add -U libgcc;
+ARG ALPINE_VERSION=3.19
+ARG RUST_VERSION=1.75
 
 ################################################################################
 
-FROM alpine AS alpine-dev
+FROM rust:$RUST_VERSION-alpine$ALPINE_VERSION AS builder
 ARG TARGETPLATFORM
 
 RUN \
     --mount=type=cache,id=$TARGETPLATFORM-alpine,target=/var/cache/apk,sharing=locked \
     set -eux; \
-    apk add -U musl-dev;
-
-################################################################################
-
-FROM --platform=$BUILDPLATFORM rust:1 AS builder
-ARG BUILDPLATFORM
-ARG TARGETPLATFORM
-
-RUN \
-    --mount=type=cache,id=$BUILDPLATFORM-debian,target=/var/cache,sharing=locked \
-    --mount=type=cache,id=$BUILDPLATFORM-debian,target=/var/lib/apt,sharing=locked \
-    set -eux; \
-    case "${TARGETPLATFORM}" in \
-        linux/i386) \
-            dpkgArch='i386'; \
-        ;; \
-        linux/amd64) \
-            dpkgArch='amd64'; \
-        ;; \
-        linux/arm64) \
-            dpkgArch='arm64'; \
-        ;; \
-        *) echo "unsupported architecture"; exit 1 ;; \
-    esac; \
-    dpkg --add-architecture $dpkgArch; \
-    apt-get update; \
-    apt-get install -y --no-install-recommends \
-        musl-dev:$dpkgArch \
-        musl-tools:$dpkgArch \
-    ;
+    apk add -U build-base;
 
 WORKDIR /opt/aode-relay
 
-RUN set -eux; \
-    case "${TARGETPLATFORM}" in \
-        linux/i386) arch='i686';; \
-        linux/amd64) arch='x86_64';; \
-        linux/arm64) arch='aarch64';; \
-        *) echo "unsupported architecture"; exit 1 ;; \
-    esac; \
-    rustup target add "${arch}-unknown-linux-musl";
-
 ADD Cargo.lock Cargo.toml /opt/aode-relay/
 RUN cargo fetch;
 
 ADD . /opt/aode-relay
-COPY --link --from=alpine-dev / /opt/alpine/
 
 RUN set -eux; \
-    case "${TARGETPLATFORM}" in \
-        linux/i386) arch='i686';; \
-        linux/amd64) arch='x86_64';; \
-        linux/arm64) arch='aarch64';; \
-        *) echo "unsupported architecture"; exit 1 ;; \
-    esac; \
-    ln -s "target/${arch}-unknown-linux-musl/release/relay" "aode-relay"; \
-    export RUSTFLAGS="-C target-cpu=generic -C linker=${arch}-linux-musl-gcc -C target-feature=-crt-static -C link-self-contained=no -L /opt/alpine/lib -L /opt/alpine/usr/lib"; \
-    cargo build --frozen --release --target="${arch}-unknown-linux-musl";
+    # https://github.com/rust-lang/compiler-team/issues/422
+    export RUSTFLAGS="-C target-cpu=generic -C target-feature=-crt-static -C link-self-contained=no"; \
+    cargo build --frozen --release;
 
 ################################################################################
 
@@ -84,7 +34,7 @@ RUN \
     set -eux; \
     apk add -U ca-certificates curl tini;
 
-COPY --link --from=builder /opt/aode-relay/aode-relay /usr/local/bin/aode-relay
+COPY --link --from=builder /opt/aode-relay/target/release/relay /usr/local/bin/aode-relay
 
 # Smoke test
 RUN /usr/local/bin/aode-relay --help