ci: add GH action to build and publish docker image

- Add GH action for build and publish the app docker image

.github/workflows/build-publish.yml

@@ -0,0 +1,45 @@
+name: Build and Publish
+
+on:
+  push:
+    branches:
+      - 'main'
+    paths:
+      - 'Dockerfile'
+      - '**.py'
+      - 'requirements.txt'
+      - '.github/workflows/build-publish.yml'
+
+jobs:
+  build_and_publish_docker_image:
+    runs-on: ubuntu-latest
+    env:
+      DOCKERHUB_REPO: 'theodore86/aws-route53'
+    steps:
+      - name: 'Checkout SCM'
+        uses: 'actions/[email protected]'
+
+      - name: 'Login to docker registry'
+        uses: 'docker/[email protected]'
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+          logout: true
+
+      - name: 'Retrieve latest commit sha as image tag'
+        id: 'git_short_sha'
+        run: |
+          short_sha=$(git log -1 --format=%h)
+          echo "::set-output name=short_sha::$short_sha"
+      
+      - name: 'Build and push docker image'
+        uses: 'docker/[email protected]'
+        with:
+          push: true
+          context: .
+          file: Dockerfile
+          no-cache: true
+          tags: |
+            ${{ env.DOCKERHUB_REPO }}:${{ steps.git_short_sha.outputs.short_sha }}
+            ${{ env.DOCKERHUB_REPO }}:latest
+