Migrate circleci to github actions

.github/workflows/build.yml

@@ -0,0 +1,48 @@
+name: Build and Push Merkle Rewards Worker Docker Image
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    environment: docker
+    env:
+      DOCKER_IMAGE: hopprotocol/merkle-drop-framework
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build application Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./backend/
+          file: ./backend/Dockerfile
+          build-args: GIT_REV=${{ github.sha }}
+          tags: app
+          load: true
+          push: false
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USER }}
+          password: ${{ secrets.DOCKER_PASS }}
+
+      - name: Push Merkle Rewards Worker Docker image to Docker Hub
+        run: |
+          BRANCH=${GITHUB_REF##*/}
+          BRANCH=$(echo $BRANCH | sed 's/\//-/g')
+          docker tag app $DOCKER_IMAGE:${{ github.sha }}
+          docker tag app $DOCKER_IMAGE:$BRANCH
+          docker push $DOCKER_IMAGE:${{ github.sha }}
+          docker push $DOCKER_IMAGE:$BRANCH
+          if [ "$BRANCH" == "master" ]; then
+            docker tag app $DOCKER_IMAGE:latest
+            docker push $DOCKER_IMAGE:latest
+          fi

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 1
+.secrets

backend/README.md

@@ -45,3 +45,11 @@ Instructions to run discourse locally with Docker, for testing discourse auto-po
 To generate api key:
 
 Preferences -> Admin -> Manage Keys -> New API Key
+
+## Github Actions
+
+Run github action build locally with [act](https://github.com/nektos/act):
+
+```sh
+(cd ../../ && act --workflows .github/workflows/build.yml)
+```