build image for arm architectures

.circleci/config.yml

@@ -1,40 +1,70 @@
 version: 2.1
 
 jobs:
-  build:
+  canary:
     docker:
       - image: cimg/base:2020.06
     working_directory: ~/docker-volume-backup
     steps:
       - checkout
-      - setup_remote_docker
+      - setup_remote_docker:
+          version: 20.10.6
       - run:
           name: Build
-          command: make build
-      - run:
-          name: Check if image needs to be pushed
           command: |
-            if [[ -z "$CIRCLE_TAG" ]]; then
-              echo "Not a git tag, nothing to do ..."
-              circleci-agent step halt
+            docker build . -t offen/docker-volume-backup:canary
+      - run:
+          name: Create container from image
+          command: |
+            docker run -d offen/docker-volume-backup:canary
+            echo "Sleeping for 30s before checking if container is still running."
+            sleep 30
+            count=$(docker ps -q | wc -l)
+            if [[ $count != "1" ]]; then
+              echo "Expected one container to be running, found $count."
+              exit 1
             fi
+            docker stop $(docker ps -q)
+
+  build:
+    docker:
+      - image: cimg/base:2020.06
+        environment:
+          DOCKER_BUILDKIT: '1'
+          DOCKER_CLI_EXPERIMENTAL: enabled
+    working_directory: ~/docker-volume-backup
+    steps:
+      - checkout
+      - setup_remote_docker:
+          version: 20.10.6
       - docker/install-docker-credential-helper
       - docker/configure-docker-credentials-store
       - run:
           name: Push to Docker Hub
           command: |
             echo "$DOCKER_ACCESSTOKEN" | docker login --username offen --password-stdin
-            docker tag offen/docker-volume-backup:local offen/docker-volume-backup:$CIRCLE_TAG
-            docker tag offen/docker-volume-backup:local offen/docker-volume-backup:latest
-            docker push offen/docker-volume-backup:$CIRCLE_TAG
-            docker push offen/docker-volume-backup:latest
+            # This is required for building ARM: https://gitlab.alpinelinux.org/alpine/aports/-/issues/12406
+            docker run --rm --privileged linuxkit/binfmt:v0.8
+            docker context create docker-volume-backup
+            docker buildx create docker-volume-backup --name docker-volume-backup --use
+            docker buildx inspect --bootstrap
+            docker buildx build --platform linux/arm64,linux/amd64 \
+              -t offen/docker-volume-backup:$CIRCLE_TAG \
+              -t offen/docker-volume-backup:latest \
+              . --push
 
 workflows:
   version: 2
-  deploy:
+  docker_image:
     jobs:
+      - canary:
+          filters:
+            tags:
+              ignore: /^v.*/
       - build:
           filters:
+            branches:
+              ignore: /.*/
             tags:
               only: /^v.*/