title: Override Environment Variables on DockerStartContainer
body: <p>I'm using the following plugin <a href="https://github.com/bmuschko/gradle-docker-plugin" rel="nofollow noreferrer">https://github.com/bmuschko/gradle-docker-plugin</a> and I'm trying to figure out how to pass environmental variables to the docker container in the task type DockerStartContainer.</p>
  
  <p>When I runn the following I get the error:</p>
  
  <blockquote>
    <p>Could not set unknown property 'VAR1' for task
    ':createDockerContainer' of type
    com.bmuschko.gradle.docker.tasks.container.DockerCreateContainer.</p>
  </blockquote>
  
  <pre class="lang-groovy prettyprint-override"><code>task buildDockerImage(type: DockerBuildImage) {
    dependsOn buildDockerAssets
    inputDir = buildDockerfile.destFile.parentFile
    tags = [ "${dockerRepo}:${project.findProperty('dockerTag') ?: 'latest'}".toString() ]
  }
  
  task createDockerContainer(type: DockerCreateContainer) {
    dependsOn buildDockerImage
    targetImageId { buildDockerImage.getImageId() }
    VAR1 = project.findProperty('VAR1') ?: 'va1'
    VAR2 = project.findProperty('VAR2') ?: 'val2'
  }
  </code></pre>
  
  <p>I'm guessing I need to do something like <code>env = ["var1=val1", "var2=val2"]</code> but I'm just not sure. Anyone know the correct way to go about this?</p>