title: Jenkins kubernetes plugin not passing environment variables with Pipeline
body: <p>Jenkins ver. 2.60.1 (running in container on kubernetes)</p>
  
  <p>Kubernetes Plugin ver. 0.11 (<a href="https://github.com/jenkinsci/kubernetes-plugin" rel="nofollow noreferrer">https://github.com/jenkinsci/kubernetes-plugin</a>)</p>
  
  <p>Pipeline test:</p>
  
  <pre><code>podTemplate(
    label: 'mypod',
    volumes: [
      persistentVolumeClaim(claimName: 'nfs-maven', mountPath: '/mnt/', readOnly: false)],
      envVars: [
        containerEnvVar(key: 'FOO', value: 'BAR'),
      ],
    containers: [
      containerTemplate(name: 'golang',
      image: 'golang',
  
      ttyEnabled: true, 
      command: 'cat',
  
      )]
  )
  {
    node('mypod') {
      stage('test env') {
  
          container('golang') {
              stage('build') {
                  sh 'echo $FOO'
                  sh 'sleep 3600'
              }
          }
      }
    }
  }
  </code></pre>
  
  <p>The vars are not passed into the containers. 
  The echo echoes nothing. echo $FOO or echo \$FOO
  I have tried on the pod level and container level.</p>
  
  <p>When i describe the created pod i only get the following environment vars:</p>
  
  <pre><code>Environment:                                                                                                                               
    JENKINS_LOCATION_URL:     http://ldn1-kube1:31000/                                                                                       
    JENKINS_SECRET:           107cb696a8792f998fd41b6ccacf833ea74941fc9a95c39c4b2a1cde4c008b35                                               
    JENKINS_JNLP_URL:         http://10.233.60.248:8080/computer/kubernetes-57beb710bfb44cea8f964d63049b2942-355760c790d6b/slave-agent.jnlp  
    JENKINS_TUNNEL:           10.233.60.248:50000                                                                                            
    JENKINS_NAME:             kubernetes-57beb710bfb44cea8f964d63049b2942-355760c790d6b                                                      
    JENKINS_URL:              http://10.233.60.248:8080                                                                                      
    HOME:                     /home/jenkins                                                                                                  
  </code></pre>