diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 09ca1db..1a502f2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -36,6 +36,21 @@ push:
     - docker push "$IMAGE_BASE:latest"
     - docker logout
 
+debug_key:
+  stage: build
+  script:
+    - echo "=== File trên runner ==="
+    - wc -c "$SSH_PRIVATE_KEY"
+    - head -1 "$SSH_PRIVATE_KEY"
+    - tail -1 "$SSH_PRIVATE_KEY"
+    - echo "=== Check ký tự ẩn (^M = CRLF) ==="
+    - cat -A "$SSH_PRIVATE_KEY" | head -2
+    - cat -A "$SSH_PRIVATE_KEY" | tail -2
+    - echo "=== Số dòng ==="
+    - wc -l "$SSH_PRIVATE_KEY"
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "main"'
+
 deploy:
   stage: deploy
   environment: