Support arm builds

.github/workflows/docker.yml

@@ -31,6 +31,28 @@ jobs:
       !contains(github.event.head_commit.message, 'ci skip') &&
       !contains(github.event.pull_request.title, 'ci skip')
     steps:
+      - name: Should we push this image to a public registry?
+        run: |
+          if [ "${{ startsWith(github.ref, 'refs/tags/') || (github.ref == 'refs/heads/main') }}" = "true" ]; then
+              # Empty => Docker Hub
+              echo "REGISTRY=" >> $GITHUB_ENV
+          else
+              echo "REGISTRY=localhost:5000/" >> $GITHUB_ENV
+          fi
+
+      # Setup docker to build for multiple platforms, see:
+      # https://github.com/docker/build-push-action/tree/v2.4.0#usage
+      # https://github.com/docker/build-push-action/blob/v2.4.0/docs/advanced/multi-platform.md
+
+      - name: Set up QEMU (for docker buildx)
+        uses: docker/setup-qemu-action@27d0a4f181a40b142cce983c5393082c365d1480 # dependabot updates to latest release
+
+      - name: Set up Docker Buildx (for multi-arch builds)
+        uses: docker/setup-buildx-action@0d135e0c2fc0dba0729c1a47ecfcf5a3c7f8579e # dependabot updates to latest release
+        with:
+          # Allows pushing to registry on localhost:5000
+          driver-opts: network=host
+
       - name: Clone Main Repo
         uses: actions/checkout@v2
         with:
@@ -67,6 +89,3 @@ jobs:
         with:
           username: ${{secrets.DOCKERHUB_USERNAME}}
           password: ${{secrets.DOCKERHUB_TOKEN}}
-      - name: Push Images to DockerHub
-        if: github.ref == 'refs/heads/master' || github.ref == 'refs/heads/main'
-        run: make -C main push-all

Makefile

@@ -7,6 +7,18 @@ SHELL:=bash
 OWNER?=jupyter
 
 # Need to list the images in build dependency order
+
+# These are images we can cross-build
+CROSS_IMAGES:= base-notebook \
+	minimal-notebook
+# These images that aren't currently supported for cross-building, your help is welcome.
+X86_IMAGES:= r-notebook \
+	scipy-notebook \
+	tensorflow-notebook \
+	datascience-notebook \
+	pyspark-notebook \
+	all-spark-notebook
+# All of the images
 ALL_IMAGES:=base-notebook \
 	minimal-notebook \
 	r-notebook \
@@ -27,11 +39,22 @@ help:
 	@echo
 	@grep -E '^[a-zA-Z0-9_%/-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
 
-build/%: DARGS?=
-build/%: ## build the latest image for a stack
-	docker build $(DARGS) --rm --force-rm -t $(OWNER)/$(notdir $@):latest --build-arg OWNER=$(OWNER) ./$(notdir $@)
+build-x86/%: DARGS?=
+build-x86/%: ## build the latest image for a stack
+	docker buildx build $(DARGS) --rm --force-rm -t $(OWNER)/$(notdir $@):latest ./$(notdir $@) --build-arg OWNER=$(OWNER) --platform "linux/amd64" --push
 	@echo -n "Built image size: "
 	@docker images $(OWNER)/$(notdir $@):latest --format "{{.Size}}"
+build-test-x86-all: $(foreach I,$(X86_IMAGES), build-x86/$(I) test/$(I) ) ## build and test all stacks
+
+build-cross/%: DARGS?=
+build-cross/%: ## build the latest image for a stack on x86 and ARM
+	docker buildx build $(DARGS) --rm --force-rm -t $(OWNER)/$(notdir $@):latest ./$(notdir $@) --build-arg OWNER=$(OWNER) --platform "linux/amd64,linux/arm64" --push
+	@echo -n "Built image size: "
+	@docker images $(OWNER)/$(notdir $@):latest --format "{{.Size}}"
+build-test-cross-all: $(foreach I,$(X86_IMAGES), build-x86/$(I) test/$(I) ) ## build and test all stacks
+
+build-all: $(foreach I,$(CROSS_IMAGES), build-cross/$(I) ) $(foreach I,$(X86_IMAGES), build/$(I) ) ## build all stacks
+build-test-all: build-all $(foreach I,$(ALL_IMAGES), test/$(I) ) ## build and test all stacks
 
 build-all: $(foreach I,$(ALL_IMAGES), build/$(I) ) ## build all stacks
 build-test-all: $(foreach I,$(ALL_IMAGES), build/$(I) test/$(I) ) ## build and test all stacks