does this work?

.gitlab-ci.yml

@@ -9,11 +9,7 @@ variables:
 
 
 stages:
-  - test
-  - coverage
-  - doc
   - docker
-  - release
   - build-singularity
   - upload-singularity
 
@@ -119,28 +115,12 @@ build-singularity:
   script:
     - singularity --version
     - singularity build $SINGULARITY_IMAGE Singularity
-  artifacts:
-    paths:
-      - $SINGULARITY_IMAGE
-    expire_in: 10 days
-  tags:
-    - docker
-  only:
-    - tags
-
-
-upload-singularity:
-  image: ubuntu:latest
-  stage: upload-singularity
-  before_script:
     - apt-get update -qy
     - apt-get install -y lftp
-  script:
     - mkdir -p ~/.ssh/
     - touch ~/.ssh/known_hosts
     - ssh-keyscan -H $KM3NET_SFTP_HOST >> ~/.ssh/known_hosts
     - lftp -u $KM3NET_SFTP_USER,$KM3NET_SFTP_PASSWORD sftp://$KM3NET_SFTP_HOST -e "set ssl:verify-certificate no; cd singularity/; put $SINGULARITY_IMAGE; bye"
-  dependencies:
-    - build-singularity
-  only:
-    - tags
+
+  tags:
+    - docker