title: Jenkins Kubernetes Plugin doesn't executre entrypoint of Docker image
body: <p>I'm fairly new into Jenkins Kubernetes Plugin and Kubernetes in general - <a href="https://github.com/jenkinsci/kubernetes-plugin" rel="nofollow noreferrer">https://github.com/jenkinsci/kubernetes-plugin</a></p>
  
  <p>I want to use the plugin for E2E tests setup inside my CI.</p>
  
  <p>Inside my <code>Jenkinsfile</code> I have a <code>podTemplate</code> which looks and used as follows:</p>
  
  <pre><code>def podTemplate = """
  apiVersion: v1
  kind: Pod
  spec:
    containers:
    - name: website
      image: ${WEBSITE_INTEGRATION_IMAGE_PATH}
      command:
        - cat
      tty: true
      ports:
       - containerPort: 3000
    - name: cypress
      resources:
        requests:
          memory: 2Gi
        limit:
          memory: 4Gi
      image: ${CYPRESS_IMAGE_PATH}
      command:
        - cat
      tty: true
  """
  
  pipeline {
    agent {
      label 'docker'
    }
    stages {
      stage('Prepare') {
        steps {
          timeout(time: 15) {
            script {
              ci_machine = docker.build("${WEBSITE_IMAGE_PATH}")
            }
          }
        }
      }
  
      stage('Build') {
        steps {
          timeout(time: 15) {
            script {
              ci_machine.inside("-u root") {
                sh "yarn build"
              }
            }
          }
        }
  
        post {
          success {
            timeout(time: 15) {
              script {
                docker.withRegistry("https://${REGISTRY}", REGISTRY_CREDENTIALS) {
                  integrationImage = docker.build("${WEBSITE_INTEGRATION_IMAGE_PATH}")
                  integrationImage.push()
                }
              }
            }
          }
        }
      }
  
      stage('Browser Tests') {
        agent {
          kubernetes {
            label "${KUBERNETES_LABEL}"
            yaml podTemplate
          }
        }
        steps {
          timeout(time: 5, unit: 'MINUTES') {
            container("website") {
              sh "yarn start"
            }
  
            container("cypress") {
              sh "yarn test:e2e"
            }
          }
        }
    }
  }
  
  
  </code></pre>
  
  <p>In <code>Dockerfile</code> that builds an image I added an <code>ENTRYPOINT</code></p>
  
  <pre><code>ENTRYPOINT ["bash", "./docker-entrypoint.sh"]
  </code></pre>
  
  <p>However it seems that it's not executed by the kubernetes plugin.</p>
  
  <p>Am I missing something?</p>