title: Is it possible to change Gitlab CI variable value after pipeline has started?
body: <p>I'm trying to create a dynamic gitlab pipeline based on it's own execution progress. For example I have 2 environments and deployment to each of them will be enabled/disabled based on the execution of the script in <strong>before_script</strong>. It doesn't work for me, seems that pipeline variable value can't be changed after pipeline has started. Any suggestions? (please see my gitlab-ci.yml below)</p>
  
  <pre><code>variables:
    RELEASE: limited
  
  stages:
    - build
    - deploy
  
  
  before_script:
    - export RELEASE=${check-release-type-dynamically.sh}
  
  build1:
    stage: build
    script:
      - echo "Do your build here"
  
  ## DEPLOYMENT
  deploy_production_ga:
    stage: update_prod_env
    script:
    - echo "deploy environment for all customers"
    allow_failure: false
    only:
    - branches
    only:
     variables:
     - $RELEASE == "general_availability"
  
  
  deploy_production_limited:
    stage: update_prod_env
    script:
    - echo "deploy environment for limited customers"
    allow_failure: false
    only:
    - branches
    only:
     variables:
     - $RELEASE == "limited"
  </code></pre>