.gitlab-ci.yml

...
Patch:
  image: maven:3.3.9
  only:
    changes:
      - "pom.xml"
    refs:
      - merge_requests
  stage: patch
  before_script:
    - POM_VERSION=$(mvn -q -Dexec.executable=echo -Dexec.args='${project.version}' --non-recursive exec:exec)
    - echo $POM_VERSION
    - git config --global user.name "alvin.h"
    - git config --global user.email "seogi777@gmail.com"
  script:
    - git checkout $CI_COMMIT_REF_NAME
    - git remote remove origin
    - git remote add origin $CI_REPOSITORY_URL
    - git tag -a $POM_VERSION -m "Version created by gitlab-ci Build"
    - git push origin --tags