Refactor deploy-image.yml to compute registry dynamically and reorder login step

.gitea/workflows/deploy-image.yml

@@ -15,19 +15,12 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
-      - name: Log in to Gitea Container Registry
-        uses: docker/login-action@v3
-        with:
-          registry: ${{ gitea.server_url && fromJSON('{}') || '' }}${{ vars.GITEA_HOST || 'git.mein-gateway.de' }}
-          username: ${{ gitea.actor }}
-          password: ${{ secrets.GITEA_TOKEN }}
-
       - name: Compute image name and tag
         id: meta
         run: |
+          REGISTRY=$(echo "${{ gitea.server_url }}" | sed 's|https\?://||')
           OWNER=$(echo "${{ gitea.repository_owner }}" | tr '[:upper:]' '[:lower:]')
-          IMAGE_NAME=$(echo "javadocviewerservice" | tr '[:upper:]' '[:lower:]')
-          REGISTRY="${{ vars.GITEA_HOST || 'git.mein-gateway.de' }}"
+          IMAGE_NAME="javadocviewerservice"
           FULL_IMAGE="${REGISTRY}/${OWNER}/${IMAGE_NAME}"
 
           REF="${{ gitea.ref_name }}"
@@ -37,10 +30,18 @@ jobs:
             TAG=$(echo "${REF}" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9._-]/-/g')
           fi
 
+          echo "registry=${REGISTRY}" >> "$GITHUB_OUTPUT"
           echo "image=${FULL_IMAGE}" >> "$GITHUB_OUTPUT"
           echo "tag=${TAG}" >> "$GITHUB_OUTPUT"
           echo "Image: ${FULL_IMAGE}:${TAG}"
 
+      - name: Log in to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ steps.meta.outputs.registry }}
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.GITEA_TOKEN }}
+
       - name: Build and push Docker image
         uses: docker/build-push-action@v5
         with: