Add multi-arch builds

Dockerfile

@@ -1,5 +1,6 @@
-FROM ubuntu:bionic
-MAINTAINER ViViDboarder <vividboarder@gmail.com>
+ARG REPO=library
+FROM ${REPO}/ubuntu:bionic
+LABEL maintainer="ViViDboarder <vividboarder@gmail.com>"
 
 RUN apt-get update \
         && apt-get install -y --no-install-recommends \

Makefile

@@ -12,7 +12,7 @@ build-x86:
 
 .PHONY: build-arm
 build-arm:
-	docker build -f ./Dockerfile -t $(DOCKER_TAG) .
+	docker build --build-arg REPO=arm32v7 -f ./Dockerfile -t $(DOCKER_TAG)-arm32v7 .
 
 .PHONY: build-all
 build-all: build-x86 build-arm

hooks/build

@@ -0,0 +1,38 @@
+#!/bin/bash
+set -ex
+
+# Extract arch repo from a docker tag suffix
+REPO=""
+case "$DOCKER_TAG" in
+    *amd64)
+        REPO="library"
+        ;;
+    *arm32v5)
+        REPO="arm32v5"
+        ;;
+    *arm32v6)
+        REPO="arm32v6"
+        ;;
+    *arm32v7)
+        REPO="arm32v7"
+        ;;
+    *arm64v8)
+        REPO="arm64v8"
+        ;;
+    *i386)
+        REPO="i386"
+        ;;
+    *ppc64le)
+        REPO="ppc64le"
+        ;;
+    *s390x)
+        REPO="s390x"
+        ;;
+    *)
+        REPO="library"
+        ;;
+esac
+
+docker build \
+    --build-arg REPO="$REPO" \
+    --tag "$IMAGE_NAME" .

hooks/post_push

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+# Use manifest-tool to create the manifest, given the experimental
+# "docker manifest" command isn't available yet on Docker Hub.
+
+curl -Lo manifest-tool https://github.com/estesp/manifest-tool/releases/download/v0.9.0/manifest-tool-linux-amd64
+chmod +x manifest-tool
+
+./manifest-tool push from-spec multi-arch-manifest.yml

hooks/pre_build

@@ -0,0 +1,39 @@
+#!/bin/bash
+set -ex
+
+REPO=""
+case "$DOCKER_TAG" in
+    *amd64)
+        REPO="library"
+        ;;
+    *arm32v5)
+        REPO="arm32v5"
+        ;;
+    *arm32v6)
+        REPO="arm32v6"
+        ;;
+    *arm32v7)
+        REPO="arm32v7"
+        ;;
+    *arm64v8)
+        REPO="arm64v8"
+        ;;
+    *i386)
+        REPO="i386"
+        ;;
+    *ppc64le)
+        REPO="ppc64le"
+        ;;
+    *s390x)
+        REPO="s390x"
+        ;;
+    *)
+        REPO="library"
+        ;;
+esac
+
+
+[ "${REPO}" != "library" ] && \
+    { echo 'qemu-user-static: Registration not required for current arch'; exit 0; }
+
+docker run --rm --privileged multiarch/qemu-user-static:register --reset

multi-arch-manifest.yml

@@ -0,0 +1,17 @@
+---
+image: vividboarder/docker-restic-cron:latest
+manifests:
+  - image: vividboarder/docker-restic-cron:amd64
+    platform:
+      architecture: amd64
+      os: linux
+  - image: vividboarder/docker-restic-cron:arm32v7
+    platform:
+      architecture: arm
+      os: linux
+      variant: v7
+  - image: vividboarder/docker-restic-cron:arm64v8
+    platform:
+      architecture: arm64
+      os: linux
+      variant: v8