Allow pushing multi-arch (linux/arm64, linux/amd64) to Docker Hub (#4)

Makefile

@@ -0,0 +1,37 @@
+SHELL := bash
+.ONESHELL:
+.SHELLFLAGS := -euc
+.DELETE_ON_ERROR:
+MAKEFLAGS += --warn-undefined-variables
+MAKEFLAGS += --no-builtin-rules
+
+VERSION := $(shell cat VERSION)
+IMAGE := pauloferrazoliveira/dogstatsd-2-statsd
+
+all:
+	echo "Current version (file VERSION) is ${VERSION}"
+	echo "Options:"
+	echo "  - make version-check"
+	echo "  - make configure-multiarch"
+	echo "  - make build-push"
+.PHONY: all
+
+version-check:
+ifndef ENV_VAR
+	@echo Version is ${VERSION}. Continue? [Y/n]
+	@read line; if [ $$line != "Y" ]; then echo "Aborting..."; exit 1 ; fi
+endif
+.PHONY: version-check
+
+configure-multiarch:
+	@echo "An error like 'ERROR: existing instance for \"multi-arch-builder\"...' is Ok, in the next line"
+	@docker buildx create --name multi-arch-builder --use || true
+.PHONY: configure-multiarch
+
+build-push: version-check
+	@$(MAKE) configure-multiarch
+	@echo "Building ${VERSION} (also as latest) and pushing..."
+	@docker buildx build --platform linux/amd64,linux/arm64 . --tag ${IMAGE}:${VERSION} --push
+	@docker buildx build --platform linux/amd64,linux/arm64 . --tag ${IMAGE}:latest --push
+	@echo "... built and pushed!"
+.PHONY: build-push

VERSION

@@ -0,0 +1 @@
+1.0.1