build(docker): build docker image and push to hub (#414)

* build(docker): build docker image and push to hub

Signed-off-by: Ameya Shenoy <shenoy.ameya@gmail.com>

* build(docker): trigger only on new release

Signed-off-by: Ameya Shenoy <shenoy.ameya@gmail.com>

.circleci/config.yml

@@ -1,4 +1,11 @@
-version: 2
+version: 2.1
+
+executors:
+  docker-publisher:
+    environment:
+      IMAGE_NAME: bukuserver/bukuserver
+    docker:
+      - image: circleci/buildpack-deps:stretch
 
 test-template: &test-template
   working_directory: ~/Buku
@@ -53,8 +60,39 @@ jobs:
             go get github.com/tcnksm/ghr
             ghr -t ${GITHUB_API_TOKEN} -u ${CIRCLE_PROJECT_USERNAME} -r ${CIRCLE_PROJECT_REPONAME} -c ${CIRCLE_SHA1} -replace ${CIRCLE_TAG} ./dist/
 
+  build-docker-image:
+    executor: docker-publisher
+    steps:
+      - checkout
+      - setup_remote_docker
+      - run:
+          name: Build Docker image
+          command: docker build -t $IMAGE_NAME:latest .
+      - run:
+          name: Archive Docker image
+          command: docker save -o image.tar $IMAGE_NAME
+      - persist_to_workspace:
+          root: .
+          paths:
+            - ./image.tar
+
+  publish-on-docker-hub:
+    executor: docker-publisher
+    steps:
+      - attach_workspace:
+          at: /tmp/workspace
+      - setup_remote_docker
+      - run:
+          name: Load archived Docker image
+          command: docker load -i /tmp/workspace/image.tar
+      - run:
+          name: Publish Docker Image to Docker Hub
+          command: |
+            echo "${DOCKERHUB_PASS}" | docker login -u "${DOCKERHUB_USERNAME}" --password-stdin
+            docker push ${IMAGE_NAME}:latest
+
 workflows:
-  version: 2
+  version: 2.1
 
   test:
     jobs: &all-tests
@@ -80,3 +118,21 @@ workflows:
               only: /^v.*/
             branches:
               ignore: /.*/
+
+  publish-docker-image:
+    jobs:
+      - build-docker-image:
+          filters:
+            tags:
+              only: /^v.*/
+            branches:
+              ignore: /.*/
+      - publish-on-docker-hub:
+          requires:
+            - build-docker-image
+          filters:
+            tags:
+              only: /^v.*/
+            branches:
+              ignore: /.*/
+