Support cross-building

.dockerignore

@@ -1,4 +1,3 @@
 # kubetest will extract kubernetes here, ignore them to speed up docker build
 kubernetes/
 kubernetes.tar.gz
-_output/

Makefile

@@ -12,24 +12,41 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ifeq ($(REGISTRY),)
-	REGISTRY = quay.io/external_storage
-endif
+REGISTRY ?= quay.io/external_storage
+VERSION ?= latest
+GOVERSION ?= 1.11.1
+# Architectures supported: amd64, arm, arm64, ppc64le and s390x
+ARCH ?= amd64
 
-ifeq ($(VERSION),)
-	VERSION = latest
-endif
+ALL_ARCH = amd64 arm arm64 ppc64le s390x
 
-ifeq ($(GOVERSION),)
-	GOVERSION = 1.11.1
-endif
+IMAGE = $(REGISTRY)/local-volume-provisioner-$(ARCH):$(VERSION)
+MUTABLE_IMAGE = $(REGISTRY)/local-volume-provisioner-$(ARCH):latest
 
-IMAGE = $(REGISTRY)/local-volume-provisioner:$(VERSION)
-MUTABLE_IMAGE = $(REGISTRY)/local-volume-provisioner:latest
+TEMP_DIR := $(shell mktemp -d)
+QEMUVERSION = v2.9.1
+
+ifeq ($(ARCH),arm)
+	QEMUARCH = arm
+endif
+ifeq ($(ARCH),arm64)
+	QEMUARCH = aarch64
+endif
+ifeq ($(ARCH),ppc64le)
+	QEMUARCH = ppc64le
+endif
+ifeq ($(ARCH),s390x)
+	QEMUARCH = s390x
+endif
+
+SUDO = $(if $(filter 0,$(shell id -u)),,sudo)
 
-all: provisioner
+all: cross
 .PHONY: all
 
+cross: $(addprefix provisioner-,$(ALL_ARCH))
+.PHONY: cross
+
 verify:
 	./hack/verify-all.sh
 .PHONY: verify
@@ -42,21 +59,38 @@ release:
 	./hack/release.sh
 .PHONY: release
 
+provisioner-%: 
+	$(MAKE) ARCH=$* provisioner
+
 provisioner:
-	docker build -t $(MUTABLE_IMAGE) --build-arg GOVERSION=${GOVERSION} -f deployment/docker/Dockerfile .
+	mkdir -p _output
+	# because COPY does not expand build arguments, we need substitute it
+	cat ./deployment/docker/Dockerfile \
+		| sed "s|QEMUARCH|$(QEMUARCH)|g" \
+		> $(TEMP_DIR)/Dockerfile
+ifeq ($(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)/Dockerfile > $(TEMP_DIR)/Dockerfile.tmp
+else
+	# When cross-building, only the placeholder "CROSS_BUILD_" should be removed
+	# Register /usr/bin/qemu-ARCH-static as the handler for non-x86 binaries in the kernel
+	$(SUDO) ./third_party/multiarch/qemu-user-static/register/register.sh --reset
+	curl -sSL https://github.com/multiarch/qemu-user-static/releases/download/$(QEMUVERSION)/x86_64_qemu-$(QEMUARCH)-static.tar.gz | tar -xz -C _output
+	# Ensure we don't get surprised by umask settings
+	chmod 0755 _output/qemu-$(QEMUARCH)-static
+	sed "s/CROSS_BUILD_//g" $(TEMP_DIR)/Dockerfile > $(TEMP_DIR)/Dockerfile.tmp
+endif
+	mv $(TEMP_DIR)/Dockerfile.tmp $(TEMP_DIR)/Dockerfile
+	docker build -t $(MUTABLE_IMAGE) --build-arg GOVERSION=$(GOVERSION) --build-arg ARCH=$(ARCH) -f $(TEMP_DIR)/Dockerfile .
 	docker tag $(MUTABLE_IMAGE) $(IMAGE)
+	rm -rf $(TEMP_DIR)
 .PHONY: provisioner
 
-push: provisioner
-	docker push $(IMAGE)
-	docker push $(MUTABLE_IMAGE)
-.PHONY: push
-
 test: provisioner
 	go test ./cmd/... ./pkg/...
-	docker run --privileged -v $(PWD)/deployment/docker/test.sh:/test.sh --entrypoint bash quay.io/external_storage/local-volume-provisioner:latest /test.sh
+	docker run --privileged -v $(PWD)/deployment/docker/test.sh:/test.sh --entrypoint bash $(IMAGE) /test.sh
 .PHONY: test
 
 clean:
-	rm -f deployment/docker/local-volume-provisioner
+	rm -rf _output
 .PHONY: clean

deployment/docker/Dockerfile

@@ -12,15 +12,22 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+ARG OS=linux
+ARG ARCH=amd64
 ARG GOVERSION=1.11.1
 FROM golang:$GOVERSION-alpine as builder
 WORKDIR /go/src/sigs.k8s.io/sig-storage-local-static-provisioner
 ADD . .
-RUN CGO_ENABLED=0 go build -a -ldflags '-extldflags "-static"' -o local-volume-provisioner ./cmd/local-volume-provisioner
+RUN CGO_ENABLED=0 GOOS=${OS} GOARCH=${ARCH} go build -a -ldflags '-extldflags "-static"' -o _output/${OS}/${ARCH}/local-volume-provisioner ./cmd/local-volume-provisioner
 
 # For security, we use kubernetes community maintained debian base image.
 # https://github.com/kubernetes/kubernetes/blob/master/build/debian-base/
-FROM k8s.gcr.io/debian-base-amd64:0.4.0
+FROM k8s.gcr.io/debian-base-${ARCH}:0.4.0
+
+# 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 _output/qemu-QEMUARCH-static /usr/bin/
 
 # Keep packages up to date and install packages for our needs.
 RUN apt-get update \
@@ -30,6 +37,6 @@ RUN apt-get update \
     e2fsprogs \
     bash
 
-COPY --from=builder /go/src/sigs.k8s.io/sig-storage-local-static-provisioner/local-volume-provisioner /local-provisioner
+COPY --from=builder /go/src/sigs.k8s.io/sig-storage-local-static-provisioner/_output/${OS}/${ARCH}/local-volume-provisioner /local-provisioner
 ADD deployment/docker/scripts /scripts
 ENTRYPOINT ["/local-provisioner"]

hack/run-e2e.sh

@@ -67,8 +67,8 @@ fi
 
 # build image if not specified
 if [ -z "$PROVISIONER_E2E_IMAGE" ]; then
-    make
-    PROVISIONER_E2E_IMAGE="quay.io/external_storage/local-volume-provisioner:latest"
+    make provisioner
+    PROVISIONER_E2E_IMAGE="quay.io/external_storage/local-volume-provisioner-amd64:latest"
 else
     docker pull $PROVISIONER_E2E_IMAGE
 fi

third_party/multiarch/qemu-user-static/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2015-2016 Manfred Touron
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

third_party/multiarch/qemu-user-static/README.kubernetes

@@ -0,0 +1 @@
+Files copied from https://github.com/multiarch/qemu-user-static at commit 22b0013668d2aed4a2cfd21650e85c664b1f21c6.