Makefile.eve

# Title: Dockerfile for building the EVE kernel
VERSION=$(shell git rev-parse --short=12 HEAD)
DIRTY=$(shell git diff --quiet || echo '-dirty')
EVE_FLAVOR=generic
ARCHITECTURE=amd64
KERNEL_TAG=v5.10.186
PLATFORM=linux/$(ARCHITECTURE)
BUILD_USER:=$(shell id -un)

IMAGE_REPOSITORY?=lfedge/eve-kernel

LINUXKIT_VERSION=58c36c9eb0c32acf66ae7877d18a9ad24d59d73e
GOBIN=/tmp/linuxkit-$(LINUXKIT_VERSION)
LK=$(GOBIN)/linuxkit

BUILD_KIT_VERSION=v0.12.5
BUILD_KIT_BUILDER=eve-kernel-builder-$(BUILD_KIT_VERSION)

SOURCE_DATE_EPOCH=$(shell git log -1 --format=%ct)
BRANCH=eve-kernel-$(ARCHITECTURE)-$(KERNEL_TAG)-$(EVE_FLAVOR)
# make sure we get a date in correct format, otherwise initramfs cpio mtime will be variable
KBUILD_BUILD_TIMESTAMP=$(shell git log -1 --format=%cd | cut -f1 -d"+")

ifeq ($(BUILDKIT_PROGRESS),)
    export BUILDKIT_PROGRESS := plain
endif

# if BRANCH is defined on a command line we are running under CI
# we add user name to DIRTY to avoid docker tag conflicts
# when building on a shared machine with shared docker cache
ifeq ($(origin BRANCH), file)
	DIRTY:=-$(BUILD_USER)$(DIRTY)
endif

.PHONY: all help

all: kernel-gcc

help: Makefile
	@echo
	@echo "Makefile to build EVE kernel"
	@echo "Usage: make [target]"
	@echo "Targets:"
	@echo "  kernel-gcc: build kernel with gcc"
	@echo "  kernel-clang: build kernel with clang"
	@echo "  docker-tag-gcc: print docker tag for gcc kernel"
	@echo "  docker-tag-clang: print docker tag for clang kernel"
	@echo "  push-gcc: push gcc kernel to docker.io"
	@echo "  push-clang: push clang kernel to docker.io"
	@echo "  clean: remove generated files"
	@echo

.PHONY: ensure-builder
ensure-builder:
	docker buildx inspect $(BUILD_KIT_BUILDER) 2>/dev/null || \
	docker buildx create --name $(BUILD_KIT_BUILDER) \
	--driver docker-container --bootstrap --driver-opt=image=moby/buildkit:$(BUILD_KIT_VERSION)

.PHONY: linuxkit
linuxkit: $(LK)
$(LK):
	GOBIN=$(GOBIN) go install github.com/linuxkit/linuxkit/src/cmd/linuxkit@$(LINUXKIT_VERSION)

KERNEL_OCI_FILE:=$(shell mktemp -u)-kernel.tar

kernel-build-%: Makefile.eve linuxkit | ensure-builder
	@echo "Building kernel version $(BRANCH):$(VERSION)-$* with compiler $*"
	docker buildx build \
	--builder=$(BUILD_KIT_BUILDER) \
	--build-arg="SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH)" \
	--build-arg="KBUILD_BUILD_TIMESTAMP=$(KBUILD_BUILD_TIMESTAMP)" \
	--build-arg="LOCALVERSION=$(VERSION)$(DIRTY)" \
	--platform $(PLATFORM) -t $(IMAGE_REPOSITORY):$(BRANCH)-$(VERSION)$(DIRTY)-$* \
	--sbom=true --output=type=oci,dest=$(KERNEL_OCI_FILE) -f Dockerfile.$* .
	$(LK) cache import $(KERNEL_OCI_FILE)
	rm -f $(KERNEL_OCI_FILE)


# we need these intermediate targets to make .PHONY work for pattern rules
kernel-gcc: kernel-build-gcc
kernel-clang: kernel-build-clang
docker-tag-gcc: docker-tag-generate-gcc
docker-tag-clang: docker-tag-generate-clang
push-gcc: push-image-gcc
push-clang: push-image-clang

.PHONY: kernel-gcc kernel-clang docker-tag-gcc docker-tag-clang push-gcc push-clang

docker-tag-generate-%:
	@echo "docker.io/$(IMAGE_REPOSITORY):$(BRANCH)-$(VERSION)$(DIRTY)-$*"

push-image-%:
	$(if $(DIRTY), $(error "Not pushing since the repo is dirty"))
	$(LK) cache push $(IMAGE_REPOSITORY):$(BRANCH)-$(VERSION)-$*

.PHONY: clean
clean:
	echo "Cleaning"