From 012ad50fbc7cd8d8b99bc906381f76aee5d7b0a5 Mon Sep 17 00:00:00 2001
From: Sascha Grunert <mail@saschagrunert.de>
Date: Fri, 12 Feb 2021 10:05:06 +0100
Subject: [PATCH] Simplify debian-base image builds

The usage of a temp dir is not necessary if we use the
`--build-arg`/`ARG` syntax within the image build. We also do not have
to assume that we're running always on x86_64, which means that the
image build should now also work on arm machines for example.

Signed-off-by: Sascha Grunert <mail@saschagrunert.de>
---
 .gitignore                                    |  2 +
 images/build/debian-base/Makefile             | 38 +++++++------------
 .../build/debian-base/buster/Dockerfile.build | 19 +++++++---
 3 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/.gitignore b/.gitignore
index 22d6f355583..e99af137769 100644
--- a/.gitignore
+++ b/.gitignore
@@ -135,3 +135,5 @@ CHANGELOG-*.html
 
 # downloaded and built binaries
 bin
+qemu-*-static
+rootfs.tar
diff --git a/images/build/debian-base/Makefile b/images/build/debian-base/Makefile
index 2870ae3e194..5a3f0bc9879 100755
--- a/images/build/debian-base/Makefile
+++ b/images/build/debian-base/Makefile
@@ -26,16 +26,14 @@ TAR_FILE ?= rootfs.tar
 ARCH ?= amd64
 ALL_ARCH = amd64 arm arm64 ppc64le s390x
 
-TEMP_DIR:=$(shell mktemp -d)
 QEMUVERSION=5.2.0-2
 
-SUDO=$(if $(filter 0,$(shell id -u)),,sudo)
-
 # This option is for running docker manifest command
 export DOCKER_CLI_EXPERIMENTAL := enabled
 
 ifeq ($(ARCH),amd64)
 	BASEIMAGE?=debian:$(CONFIG)-slim
+	QEMUARCH=x86_64
 endif
 ifeq ($(ARCH),arm)
 	BASEIMAGE?=arm32v7/debian:$(CONFIG)-slim
@@ -72,49 +70,39 @@ push-manifest:
 	docker manifest push --purge ${IMAGE}:${IMAGE_VERSION}
 
 build: clean
-	cp -r ./$(CONFIG) $(TEMP_DIR)/
-	cat $(CONFIG)/Dockerfile.build \
-		| sed "s|BASEIMAGE|$(BASEIMAGE)|g" \
-		| sed "s|ARCH|$(QEMUARCH)|g" \
-		> $(TEMP_DIR)/$(CONFIG)/Dockerfile.build
+	# Fix possible issues with the local umask
+	umask 0022
 
-ifeq ($(ARCH),amd64)
-	# When building "normally" for amd64, remove the whole line, it has no part in the amd64 image
-	sed "/CROSS_BUILD_/d" $(TEMP_DIR)/$(CONFIG)/Dockerfile.build > $(TEMP_DIR)/$(CONFIG)/Dockerfile.build.tmp
-else
 	# Register /usr/bin/qemu-ARCH-static as the handler for non-x86 binaries in the kernel
 	docker run --rm --privileged multiarch/qemu-user-static:$(QEMUVERSION) --reset -p yes
 	docker buildx version
 	BUILDER=$(shell docker buildx create --use)
 
-	curl -sSL https://github.com/multiarch/qemu-user-static/releases/download/v$(QEMUVERSION)/x86_64_qemu-$(QEMUARCH)-static.tar.gz | tar -xz -C $(TEMP_DIR)/$(CONFIG)
+	curl -sSL https://github.com/multiarch/qemu-user-static/releases/download/v$(QEMUVERSION)/x86_64_qemu-$(QEMUARCH)-static.tar.gz | tar -xz -C $(CONFIG)
 	# Ensure we don't get surprised by umask settings
-	chmod 0755 $(TEMP_DIR)/$(CONFIG)/qemu-$(QEMUARCH)-static
-
-	# When cross-building, only the placeholder "CROSS_BUILD_" should be removed
-	sed "s/CROSS_BUILD_//g" $(TEMP_DIR)/$(CONFIG)/Dockerfile.build > $(TEMP_DIR)/$(CONFIG)/Dockerfile.build.tmp
-endif
-	mv $(TEMP_DIR)/$(CONFIG)/Dockerfile.build.tmp $(TEMP_DIR)/$(CONFIG)/Dockerfile.build
+	chmod 0755 $(CONFIG)/qemu-$(QEMUARCH)-static
 
 	docker buildx build \
 		--pull \
 		--load \
 		--platform linux/$(ARCH) \
+		--build-arg BASEIMAGE=$(BASEIMAGE) \
+		--build-arg ARCH=$(QEMUARCH) \
 		-t $(BUILD_IMAGE) \
-		-f $(TEMP_DIR)/$(CONFIG)/Dockerfile.build $(TEMP_DIR)/$(CONFIG)
+		-f $(CONFIG)/Dockerfile.build \
+		$(CONFIG)
 	docker create --name $(BUILD_IMAGE) $(BUILD_IMAGE)
-	docker export $(BUILD_IMAGE) > $(TEMP_DIR)/$(CONFIG)/$(TAR_FILE)
+	docker export $(BUILD_IMAGE) > $(CONFIG)/$(TAR_FILE)
 	docker buildx build \
 		--load \
 		--platform linux/$(ARCH) \
 		-t $(IMAGE)-$(ARCH):$(IMAGE_VERSION) \
 		-t $(IMAGE)-$(ARCH):$(TAG)-$(CONFIG) \
 		-t $(IMAGE)-$(ARCH):latest-$(CONFIG) \
-		$(TEMP_DIR)/$(CONFIG)
-	rm -rf $(TEMP_DIR)
-ifneq ($(ARCH),amd64)
+		$(CONFIG)
 	docker buildx rm $$BUILDER
-endif
+	rm $(CONFIG)/qemu-$(QEMUARCH)-static
+	rm $(CONFIG)/rootfs.tar
 
 push: build
 	docker push $(IMAGE)-$(ARCH):$(IMAGE_VERSION)
diff --git a/images/build/debian-base/buster/Dockerfile.build b/images/build/debian-base/buster/Dockerfile.build
index 22bd98201b4..d29c8ae40c9 100644
--- a/images/build/debian-base/buster/Dockerfile.build
+++ b/images/build/debian-base/buster/Dockerfile.build
@@ -12,12 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM BASEIMAGE
+ARG BASEIMAGE
+FROM $BASEIMAGE
 
-# If we're building for another architecture than amd64, the CROSS_BUILD_ placeholder is removed so
-# e.g. CROSS_BUILD_COPY turns into COPY
-# If we're building normally, for amd64, CROSS_BUILD lines are removed
-CROSS_BUILD_COPY qemu-ARCH-static /usr/bin/
+ARG ARCH
+COPY qemu-$ARCH-static /usr/bin/
 
 ENV DEBIAN_FRONTEND=noninteractive
 
@@ -27,6 +26,16 @@ COPY excludes /etc/dpkg/dpkg.cfg.d/excludes
 # Convenience script for building on this base image.
 COPY clean-install /usr/local/bin/clean-install
 
+# An attempt to fix issues like:
+# ```
+# Error while loading /usr/sbin/dpkg-split: No such file or directory
+# Error while loading /usr/sbin/dpkg-deb: No such file or directory
+# ```
+# See: https://github.com/docker/buildx/issues/495
+RUN ln -s /usr/bin/dpkg-split /usr/sbin/dpkg-split
+RUN ln -s /usr/bin/dpkg-deb /usr/sbin/dpkg-deb
+RUN ln -s /bin/tar /usr/sbin/tar
+
 # Update system packages.
 RUN apt-get update \
     && apt-get dist-upgrade -y