Add native x86_64 musl toolchain

Allows local development without dependending on musl being installed on the development machine.

Signed-off-by: Paulo Gomes <paulo.gomes@weave.works>

Author: Paulo Gomes

Makefile

@@ -27,14 +27,12 @@ else
 endif
 
 ifeq ($(shell uname -s),Linux)
-ifneq ($(shell uname -m),x86_64)
-	MUSL-PREFIX=$(REPOSITORY_ROOT)/build/musl/aarch64-linux-musl-native/bin/aarch64-linux-musl
+	MUSL-PREFIX=$(REPOSITORY_ROOT)/build/musl/$(shell uname -m)-linux-musl-native/bin/$(shell uname -m)-linux-musl
 	MUSL-CC=$(MUSL-PREFIX)-gcc
 	export CC=$(MUSL-PREFIX)-gcc
 	export CXX=$(MUSL-PREFIX)-g++
 	export AR=$(MUSL-PREFIX)-ar
 endif
-endif
 
 GO_STATIC_FLAGS=-tags 'netgo,osusergo,static_build'
 
@@ -70,8 +68,6 @@ builder:
 # install qemu emulators
 	docker run -it --rm --privileged tonistiigi/binfmt --install all
 
-$(MUSL-CC):
-	./hack/download-musl.sh
 
 $(LIBGIT2): $(MUSL-CC)
 ifeq ($(shell uname -s),Darwin)
@@ -81,6 +77,12 @@ else
 	IMG_TAG=$(IMG):$(TAG) ./hack/extract-libraries.sh
 endif
 
+$(MUSL-CC):
+ifneq ($(shell uname -s),Darwin)
+	./hack/download-musl.sh
+endif
+
+
 # dev-test is a smoke test for development environment
 # consuming the libraries generated by this project.
 dev-test: $(LIBGIT2)

hack/download-musl.sh

@@ -1,20 +1,32 @@
 #!/usr/bin/env bash
 
+set -eoux pipefail
+
+MUSL_X86_64_FILENAME=x86_64-linux-musl-native.tgz
+MUSL_X86_64_SHA512=44d441ad9aa11a06feddf3daa4c9f53ad7d9ca37af1f5a61379aca07793703d179410cea723c1b7fca94c4de19a321228bdb3656bc5cbdb5e3bea8e2d6dac6c7
 MUSL_AARCH64_FILENAME=aarch64-linux-musl-native.tgz
-MUSL_AARCH64_URL="https://more.musl.cc/11.2.1/x86_64-linux-musl/${MUSL_AARCH64_FILENAME}"
 MUSL_AARCH64_SHA512=16d544e09845c9dbba50f29e0cb04dd661e17eb63c56acad6a67fd2a78aa7596b792477c7177d3cd56d408a27dc291a90507df882f2b099c0f25511ce08fd3b5
 
+MUSL_FILENAME="${MUSL_X86_64_FILENAME}"
+MUSL_SHA512="${MUSL_X86_64_SHA512}"
+if [ "$(uname -m)" = "arm64" ] || [ "$(uname -m)" = "aarch64" ]; then
+    MUSL_FILENAME="${MUSL_AARCH64_FILENAME}"
+    MUSL_SHA512="${MUSL_AARCH64_SHA512}"
+fi
+
+MUSL_AARCH64_URL="https://more.musl.cc/11.2.1/x86_64-linux-musl/${MUSL_FILENAME}"
+
 ROOT_DIR="$(git rev-parse --show-toplevel)"
 MUSL_DIR="${ROOT_DIR}/build/musl"
 
 if [ ! -f "${MUSL_DIR}/bin" ]; then
-    TARGET_FILE="${MUSL_DIR}/${MUSL_AARCH64_FILENAME}"
+    TARGET_FILE="${MUSL_DIR}/${MUSL_FILENAME}"
     mkdir -p "${MUSL_DIR}"
 
-    echo "${MUSL_AARCH64_SHA512}  ${TARGET_FILE}"
+    echo "${MUSL_SHA512}  ${TARGET_FILE}"
     curl -o "${TARGET_FILE}" -LO "${MUSL_AARCH64_URL}"
-    if ! echo "${MUSL_AARCH64_SHA512}  ${TARGET_FILE}" | sha512sum --check; then
-        echo "Checksum failed for ${MUSL_AARCH64_FILENAME}."
+    if ! echo "${MUSL_SHA512}  ${TARGET_FILE}" | sha512sum --check; then
+        echo "Checksum failed for ${MUSL_FILENAME}."
         rm -rf "${MUSL_DIR}"
         exit 1
     fi

hack/extract-libraries.sh

@@ -1,14 +1,14 @@
 #!/usr/bin/env bash
 
-set -euxo pipefail
+set -eoux pipefail
 
 IMG_TAG="${IMG_TAG:-.}"
 
 function extract(){
     PLATFORM=$1
     DIR=$2
 
-    id=$(docker create --platform="${PLATFORM}" "${IMG_TAG}")
+    id=$(docker create --platform="${PLATFORM}" "${IMG_TAG}" sh)
     docker cp "${id}":/usr/local - > output.tar.gz
     docker rm -v "${id}"