Docker cross-compilation github workflow.

docker/Dockerfile

@@ -1,9 +1,10 @@
+# Depends on either outputs of Dockerfile.xx or the binaries compiled elsewhere.
 FROM scratch
 
-ARG TARGETPLATFORM
-
 ADD https://curl.se/ca/cacert.pem /etc/ssl/cacerts.pem
 
+ARG TARGETPLATFORM
+
 ## Assumes you are running this from respective context folder.
 COPY --chmod=755 ${TARGETPLATFORM}/rqbit /bin/rqbit
 

docker/Dockerfile.xx

@@ -0,0 +1,42 @@
+# Dockerfile for cross compiling rqbit binaries from scratch inside docker.
+FROM --platform=$BUILDPLATFORM tonistiigi/xx AS xx
+
+FROM --platform=$BUILDPLATFORM rust:alpine AS builder
+COPY --from=xx / /
+
+RUN apk update && apk add clang lld npm python3 perl make
+
+ARG TARGETPLATFORM
+RUN xx-apk add gcc musl-dev
+
+COPY / /src/
+WORKDIR /src/
+
+ENV PROFILE_NAME=release-github
+ENV PROFILE_FOLDER=release-github
+
+RUN --mount=type=cache,target=/usr/local/cargo/git/db \
+    --mount=type=cache,target=/usr/local/cargo/registry/cache \
+    --mount=type=cache,target=/usr/local/cargo/registry/index \
+    --mount=type=cache,target=/src/target <<EOF
+set -e
+export TT="$(xx-cargo --print-target-triple)"
+export BIN="./target/${TT}/${TT}/${PROFILE_FOLDER}/rqbit"
+
+find /src/target \
+        /usr/local/cargo/git/db \
+        /usr/local/cargo/registry/cache \
+        /usr/local/cargo/registry/index \
+        -maxdepth 2 -type d
+xx-cargo build \
+    --target-dir "target/${TT}" \
+    --profile "${PROFILE_NAME}" \
+    --no-default-features --features rust-tls,webui
+find /src/target -maxdepth 4 -type d
+xx-verify --static "${BIN}"
+mv "${BIN}" /bin/rqbit
+EOF
+
+FROM scratch
+
+COPY --from=builder /bin/rqbit /rqbit