title: Bitbucket pipeline - assign custom variables
body: <p>I would like to assign custom variables using bash commands</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>image: alpine
  
  pipelines:
    default:
        - step:
            name: docker-login
            services:
              - docker
            script:
              - docker login --username $DOCKER_USERNAME --password $DOCKER_PASSWORD
              - echo "logged in to docker hub"
              - echo $VERSION
            variables:
              VERSION: cat ./version.txt
        - step: 
            name: build-image
            services:
              - docker
            script:
              - echo "running docker image test"
        - step:
            name: 'set ssh env'
            script:
              - pipe: atlassian/ssh-run:0.4.0
                variables:
                  SSH_USER: $SSH_USER
                  SERVER: '$HOST'
                  COMMAND: 'pwd'</code></pre>
  </div>
  </div>
  </p>
  <p>I am not getting the output of the file.. what is the correct syntax?</p>