Add Docker scripts for ARM static builds

Dockerfile

@@ -0,0 +1,7 @@
+ARG BASE_IMAGE
+FROM ${BASE_IMAGE}
+
+ARG TARGET
+ENV TARGET=${TARGET}
+
+WORKDIR /work

README.md

@@ -32,6 +32,19 @@ you will help support:
 - Unpack and put the binary somewhere in your PATH (i.e. `/usr/local/bin` on linux and macos)
 - Note that the binary is not code signed and will cause a warning on windows and macos when running. This will be fixed later, but for now you can find a workaround via your favorite search engine.
 
+### Build static ARM binaries (Docker)
+
+This repository includes Docker scripts for building static ARM binaries with musl.
+
+- ARM64 (aarch64):
+  - `./dockerbuild.sh aarch64-unknown-linux-musl`
+  - `./indockerbuild.sh aarch64-unknown-linux-musl`
+  - Output: `dist/aarch64-unknown-linux-musl/gdrive`
+- ARM32 (armv7):
+  - `./dockerbuild.sh armv7-unknown-linux-musleabihf`
+  - `./indockerbuild.sh armv7-unknown-linux-musleabihf`
+  - Output: `dist/armv7-unknown-linux-musleabihf/gdrive`
+
 ### Add google account to gdrive
 
 - Run `gdrive account add`

dockerbuild.sh

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+#!/usr/bin/env bash
+set -euo pipefail
+
+TARGET="${1:-aarch64-unknown-linux-musl}"
+case "${TARGET}" in
+  aarch64-unknown-linux-musl)
+    BASE_IMAGE="messense/rust-musl-cross:aarch64-musl"
+    ;;
+  armv7-unknown-linux-musleabihf)
+    BASE_IMAGE="messense/rust-musl-cross:armv7-musleabihf"
+    ;;
+  *)
+    echo "Unsupported target: ${TARGET}"
+    exit 1
+    ;;
+esac
+
+IMAGE="gdrive-build:${TARGET}"
+
+docker build \
+  --build-arg TARGET="${TARGET}" \
+  --build-arg BASE_IMAGE="${BASE_IMAGE}" \
+  -t "${IMAGE}" \
+  -f Dockerfile \
+  .

indockerbuild.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+TARGET="${1:-aarch64-unknown-linux-musl}"
+OUT_DIR="${2:-$(pwd)/dist/${TARGET}}"
+IMAGE="gdrive-build:${TARGET}"
+
+mkdir -p "${OUT_DIR}"
+
+docker run --rm \
+  -v "$(pwd)":/work \
+  -v "${OUT_DIR}":/out \
+  -w /work \
+  "${IMAGE}" \
+  /bin/sh -c "cargo build --release --target ${TARGET} && cp target/${TARGET}/release/gdrive /out/gdrive"