Create docker-image.yml

trigger docker build process when tag is created

.github/workflows/docker-image.yml

@@ -0,0 +1,35 @@
+name: Docker Image CI
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v2
+
+    - name: Extract version tag
+      id: extract_tag
+      run: echo "TAG=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
+
+    - name: Log in to Docker Hub
+      uses: docker/login-action@v2
+      with:
+        username: ${{ secrets.DOCKER_USERNAME }}
+        password: ${{ secrets.DOCKER_PASSWORD }}
+
+    - name: Build and push Docker image
+      uses: docker/build-push-action@v4
+      with:
+        context: .
+        file: ./docker/Dockerfile
+        push: true
+        tags: opencsg/csghub-server:${{ env.TAG }}