chore: CI Automated Builds (#2409)

closes #2408

.circleci/config.yml

@@ -1,4 +1,12 @@
-version: 2
+version: 2.1
+
+executors:
+  docker-publisher:
+    environment:
+      IMAGE_NAME: outlinewiki/outline
+    docker:
+      - image: circleci/buildpack-deps:stretch
+
 jobs:
   build:
     working_directory: ~/outline
@@ -40,4 +48,88 @@ jobs:
           command: yarn test
       - run:
           name: build-webpack
-          command: yarn build:webpack
+          command: yarn build:webpack
+  build-image:
+    executor: docker-publisher
+    steps:
+      - checkout
+      - setup_remote_docker:
+          version: 20.10.6
+      - run:
+          name: Build Docker image
+          command: docker build -t $IMAGE_NAME:latest .
+      - run:
+          name: Archive Docker image
+          command: docker save -o image.tar $IMAGE_NAME
+      - persist_to_workspace:
+          root: .
+          paths:
+            - ./image.tar
+  publish-latest:
+    executor: docker-publisher
+    steps:
+      - attach_workspace:
+          at: /tmp/workspace
+      - setup_remote_docker:
+          version: 20.10.6
+      - run:
+          name: Load archived Docker image
+          command: docker load -i /tmp/workspace/image.tar
+      - run:
+          name: Publish Docker Image to Docker Hub
+          command: |
+            echo "$DOCKERHUB_PASS" | docker login -u "$DOCKERHUB_USERNAME" --password-stdin
+            IMAGE_TAG=version-${CIRCLE_TAG/v/''}
+            docker tag $IMAGE_NAME:latest $IMAGE_NAME:$IMAGE_TAG
+            docker push $IMAGE_NAME:latest
+            docker push $IMAGE_NAME:$IMAGE_TAG
+  publish-tag:
+    executor: docker-publisher
+    steps:
+      - attach_workspace:
+          at: /tmp/workspace
+      - setup_remote_docker:
+          version: 20.10.6
+      - run:
+          name: Load archived Docker image
+          command: docker load -i /tmp/workspace/image.tar
+      - run:
+          name: Publish Docker Image to Docker Hub
+          command: |
+            echo "$DOCKERHUB_PASS" | docker login -u "$DOCKERHUB_USERNAME" --password-stdin
+            IMAGE_TAG=version-${CIRCLE_TAG/v/''}
+            docker tag $IMAGE_NAME:latest $IMAGE_NAME:$IMAGE_TAG
+            docker push $IMAGE_NAME:$IMAGE_TAG
+
+workflows:
+  version: 2
+  build-and-test:
+    jobs:
+      - build:
+          filters:
+            tags:
+              ignore: /^v.*/
+  build-docker:
+    jobs:
+      - build-image:
+          filters:
+            tags:
+              only: /^v.*/
+            branches:
+              ignore: /.*/
+      - publish-latest:
+          requires:
+            - build-image
+          filters:
+            tags:
+              only: /^v\d+\.\d+\.\d+$/
+            branches:
+              ignore: /.*/
+      - publish-tag:
+          requires:
+            - build-image
+          filters:
+            tags:
+              only: /^v\d+\.\d+\.\d+-.*$/
+            branches:
+              ignore: /.*/