Optimise target image for cross compilation

Dockerfile

@@ -5,11 +5,7 @@ ARG XX_VERSION=1.1.0
 
 FROM --platform=$BUILDPLATFORM tonistiigi/xx:${XX_VERSION} AS xx
 
-FROM golang:${GO_VERSION}-${BASE_VARIANT} as gostable
-
-FROM gostable AS go-linux
-
-FROM --platform=$BUILDPLATFORM ${BASE_VARIANT} AS build-deps
+FROM --platform=$BUILDPLATFORM ${BASE_VARIANT} AS build-base
 
 RUN apk add --no-cache \
         bash \
@@ -26,15 +22,10 @@ RUN apk add --no-cache \
 
 COPY --from=xx / /
 
-ARG TARGETPLATFORM
-
-RUN xx-apk add --no-cache \
-        xx-c-essentials 
-
-RUN xx-apk add --no-cache \
-        xx-cxx-essentials 
+FROM build-base AS build-cross
 
 ARG TARGETPLATFORM
+
 RUN xx-apk add --no-cache \
         build-base \
         pkgconfig \
@@ -48,7 +39,6 @@ RUN xx-apk add --no-cache \
 WORKDIR /build
 COPY hack/static.sh .
 
-ARG TARGETPLATFORM
 ENV CC=xx-clang
 ENV CXX=xx-clang++
 
@@ -68,12 +58,25 @@ RUN ./static.sh build_libssh2
 RUN ./static.sh build_libgit2
 
 
-FROM go-${TARGETOS} AS build
+# trimmed removes all non necessary files (i.e. openssl binary).
+FROM build-cross AS trimmed
 
-# Copy cross-compilation tools
-COPY --from=xx / /
-# Copy compiled libraries
-COPY --from=build-deps /usr/local/ /usr/local/
+ARG TARGETPLATFORM
+RUN mkdir -p /trimmed/usr/local/$(xx-info triple)/ && \
+        mkdir -p /trimmed/usr/local/$(xx-info triple)/share
+
+RUN cp -r /usr/local/$(xx-info triple)/lib/ /trimmed/usr/local/$(xx-info triple)/ && \
+        cp -r /usr/local/$(xx-info triple)/lib64/ /trimmed/usr/local/$(xx-info triple)/ | true && \
+        cp -r /usr/local/$(xx-info triple)/include/ /trimmed/usr/local/$(xx-info triple)/ && \
+        cp -r /usr/local/$(xx-info triple)/share/doc/ /trimmed/usr/local/$(xx-info triple)/share/
+
+FROM scratch as libs-arm64
+COPY --from=trimmed /trimmed/ /
+
+FROM scratch as libs-amd64
+COPY --from=trimmed /trimmed/ /
+
+FROM scratch as libs-armv7
+COPY --from=trimmed /trimmed/ /
 
-COPY ./hack/Makefile /Makefile
-COPY ./hack/static.sh /static.sh
+FROM libs-$TARGETARCH$TARGETVARIANT as libs

Dockerfile.test

@@ -1,107 +1,59 @@
-# This Dockerfile tests the hack/Makefile output against git2go.
 ARG BASE_VARIANT=alpine
-ARG GO_VERSION=1.17.6
+ARG GO_VERSION=1.17
 ARG XX_VERSION=1.1.0
 
-FROM --platform=$BUILDPLATFORM tonistiigi/xx:${XX_VERSION} AS xx
-
-FROM golang:${GO_VERSION}-${BASE_VARIANT} as gostable
-
-FROM gostable AS go-linux
-
-FROM --platform=$BUILDPLATFORM ${BASE_VARIANT} AS build-deps
-
-RUN apk add --no-cache \
-        bash \
-        curl \
-        build-base \
-        linux-headers \
-        perl \
-        cmake \
-        pkgconfig \
-        gcc \
-        musl-dev \
-        clang \
-        lld
-
-COPY --from=xx / /
+ARG LIBGIT2_IMG
+ARG LIBGIT2_TAG
 
-ARG TARGETPLATFORM
-
-RUN xx-apk add --no-cache \
-        xx-c-essentials 
-
-RUN xx-apk add --no-cache \
-        xx-cxx-essentials 
-
-ARG TARGETPLATFORM
-RUN xx-apk add --no-cache \
-        build-base \
-        pkgconfig \
-        gcc \
-        musl-dev \
-        clang \
-        lld \
-        llvm \
-        linux-headers
-
-WORKDIR /build
-COPY hack/static.sh .
-
-ARG TARGETPLATFORM
-ENV CC=xx-clang
-ENV CXX=xx-clang++
+FROM ${LIBGIT2_IMG}:${LIBGIT2_TAG} AS build-deps
 
-RUN CHOST=$(xx-clang --print-target-triple) \
-    ./static.sh build_libz
-
-RUN CHOST=$(xx-clang --print-target-triple) \
-    ./static.sh build_openssl
+FROM --platform=$BUILDPLATFORM tonistiigi/xx:${XX_VERSION} AS xx
 
-RUN export LIBRARY_PATH="/usr/local/$(xx-info triple)/lib:/usr/local/$(xx-info triple)/lib64:${LIBRARY_PATH}" && \
-    export PKG_CONFIG_PATH="/usr/local/$(xx-info triple)/lib/pkgconfig:/usr/local/$(xx-info triple)/lib64/pkgconfig" && \
-    export OPENSSL_ROOT_DIR="/usr/local/$(xx-info triple)" && \
-    export OPENSSL_CRYPTO_LIBRARY="/usr/local/$(xx-info triple)/lib64" && \
-    export OPENSSL_INCLUDE_DIR="/usr/local/$(xx-info triple)/include/openssl"
+FROM --platform=$BUILDPLATFORM golang:${GO_VERSION}-${BASE_VARIANT} as gostable
 
-RUN ./static.sh build_libssh2
-RUN ./static.sh build_libgit2
+FROM gostable AS go-linux
 
+# Build-base consists of build platform dependencies and xx.
+# These will be used at current arch to yield execute the cross compilations.
+FROM go-${TARGETOS} AS build-base
 
-FROM go-${TARGETOS} AS build
+RUN apk add clang lld pkgconfig
 
-# Copy cross-compilation tools
 COPY --from=xx / /
-# Copy compiled libraries
-COPY --from=build-deps /usr/local/ /usr/local/
 
-RUN apk add clang lld pkgconfig
+# build-go-mod can still be cached at build platform architecture.
+FROM build-base as build-go-mod
 
 WORKDIR /root/smoketest
 COPY tests/smoketest/go.mod .
 COPY tests/smoketest/go.sum .
 RUN go mod download
 
+# Build stage install per target platform
+# dependency and effectively cross compile the application.
+FROM build-go-mod as build
+
 ARG TARGETPLATFORM
 
 # Some dependencies have to installed 
 # for the target platform: https://github.com/tonistiigi/xx#go--cgo
-RUN xx-apk add --no-cache \
-        musl-dev \
-        gcc
+RUN xx-apk add musl-dev gcc clang lld
 
+WORKDIR /root/smoketest
 
 COPY tests/smoketest/main.go .
+COPY --from=build-deps /usr/local/ /usr/local/
 
 ENV CGO_ENABLED=1
-RUN export LIBRARY_PATH="/usr/local/$(xx-info triple)/lib:/usr/local/$(xx-info triple)/lib64:${LIBRARY_PATH}" && \
+RUN export LIBRARY_PATH="/usr/local/$(xx-info triple):/usr/local/$(xx-info triple)/lib64" && \
     export PKG_CONFIG_PATH="/usr/local/$(xx-info triple)/lib/pkgconfig:/usr/local/$(xx-info triple)/lib64/pkgconfig" && \
-	export FLAGS="$(pkg-config --static --libs --cflags libssh2 openssl libgit2)" && \
-    CGO_LDFLAGS="${FLAGS} -static" \
-	xx-go build \
+    export FLAGS="$(pkg-config --static --libs --cflags libssh2 openssl libgit2)" && \
+    export CGO_LDFLAGS="${FLAGS} -static" && \
+    xx-go build  \
         -ldflags "-s -w" \
         -tags 'netgo,osusergo,static_build' \
-        -o static-test-runner -trimpath main.go;
+        -o static-test-runner -trimpath main.go
+
 
 # Ensure that the generated binary is valid for the target platform
 RUN xx-verify --static static-test-runner
@@ -119,11 +71,4 @@ COPY --from=build \
 
 ENV SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt
 
-# To do docker run instead, replace the RUN statement with:
-# ENTRYPOINT [ "/root/smoketest/static-test-runner" ]
-
-# The approach below was preferred as it provides a way to 
-# assert the functionality across the supported architectures 
-# without any extra steps.
-
 RUN /root/smoketest/static-test-runner

Makefile

@@ -1,10 +1,42 @@
-IMG ?= hiddeco/golang-with-libgit2
+IMG ?= ghcr.io/fluxcd/golang-with-libgit2
 TAG ?= latest
-STATIC_TEST_TAG := test
 
 PLATFORMS ?= linux/amd64,linux/arm/v7,linux/arm64
 BUILD_ARGS ?=
 
+REPOSITORY_ROOT := $(shell git rev-parse --show-toplevel)
+TARGET_DIR ?= $(REPOSITORY_ROOT)/build/libgit2
+BUILD_ROOT_DIR ?= $(REPOSITORY_ROOT)/build/libgit2-src
+
+LIBGIT2_PATH := $(TARGET_DIR)
+LIBGIT2_LIB_PATH := $(LIBGIT2_PATH)/lib
+LIBGIT2_LIB64_PATH := $(LIBGIT2_PATH)/lib64
+LIBGIT2 := $(LIBGIT2_LIB_PATH)/libgit2.a
+MUSL-CC =
+
+export CGO_ENABLED=1
+export LIBRARY_PATH=$(LIBGIT2_LIB_PATH):$(LIBGIT2_LIB64_PATH)
+export PKG_CONFIG_PATH=$(LIBGIT2_LIB_PATH)/pkgconfig:$(LIBGIT2_LIB64_PATH)/pkgconfig
+export CGO_CFLAGS=-I$(LIBGIT2_PATH)/include
+
+
+ifeq ($(shell uname -s),Linux)
+	export CGO_LDFLAGS=$(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) pkg-config --libs --static --cflags libssh2 openssl libgit2) -static
+else
+	export CGO_LDFLAGS=$(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) pkg-config --libs --static --cflags libssh2 openssl libgit2) -Wl,--unresolved-symbols=ignore-in-object-files -Wl,-allow-shlib-undefined -static
+endif
+
+ifeq ($(shell uname -s),Linux)
+	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=$(MUSL-PREFIX)-ar
+endif
+
+GO_STATIC_FLAGS=-tags 'netgo,osusergo,static_build'
+
+
 .PHONY: build
 build:
 	docker buildx build \
@@ -17,7 +49,9 @@ build:
 test:
 	docker buildx build \
 		--platform=$(PLATFORMS) \
-		--tag $(IMG):$(TAG) \
+		--tag $(IMG):$(TAG)-test \
+		--build-arg LIBGIT2_IMG=$(IMG) \
+		--build-arg LIBGIT2_TAG=$(TAG) \
 		--file Dockerfile.test \
 		$(BUILD_ARGS) .
 
@@ -33,3 +67,24 @@ builder:
 		--use
 # install qemu emulators
 	docker run -it --rm --privileged tonistiigi/binfmt --install all
+
+
+$(LIBGIT2): $(MUSL-CC)
+ifeq ($(shell uname -s),Darwin)
+	TARGET_DIR=$(TARGET_DIR) BUILD_ROOT_DIR=$(BUILD_ROOT_DIR) \
+		./hack/static.sh all
+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)
+	cd tests/smoketest; go vet $(GO_STATIC_FLAGS) ./...
+	cd tests/smoketest; go run $(GO_STATIC_FLAGS) main.go

hack/download-musl.sh

@@ -0,0 +1,36 @@
+#!/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_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_FILENAME}"
+    mkdir -p "${MUSL_DIR}"
+
+    echo "${MUSL_SHA512}  ${TARGET_FILE}"
+    curl -o "${TARGET_FILE}" -LO "${MUSL_AARCH64_URL}"
+    if ! echo "${MUSL_SHA512}  ${TARGET_FILE}" | sha512sum --check; then
+        echo "Checksum failed for ${MUSL_FILENAME}."
+        rm -rf "${MUSL_DIR}"
+        exit 1
+    fi
+
+    tar xzf "${TARGET_FILE}" -C "${MUSL_DIR}"
+    rm "${TARGET_FILE}"
+fi