added docker-push.yaml workflow

.gitea/workflows/docker-push.yaml

@@ -0,0 +1,41 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Check if Dockerfile exists
+        id: check_dockerfile
+        run: |
+          if [ -f "Dockerfile" ]; then
+            echo "exists=true" >> $GITHUB_ENV
+          else
+            echo "exists=false" >> $GITHUB_ENV
+          fi
+
+      - name: Set repository name as image name
+        if: env.exists == 'true'
+        run: echo "IMAGE_NAME=${{ github.repository }}" >> $GITHUB_ENV
+
+      - name: Log in to Docker registry
+        if: env.exists == 'true'
+        run: |
+          echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login git.ionas999.at -u ${{ secrets.REGISTRY_USERNAME }} --password-stdin
+
+      - name: Build Docker image
+        if: env.exists == 'true'
+        run: |
+          docker build -t git.ionas999.at/${{ env.IMAGE_NAME }}:latest .
+
+      - name: Push Docker image
+        if: env.exists == 'true'
+        run: |
+          docker push git.ionas999.at/${{ env.IMAGE_NAME }}:latest