We use Docker to set up our testing environments with Jenkins and install the application in it. Every build will be installed in a Docker Container automatically. The Container is used for acceptance tests. The Docker Containers are set up automatically with a Dockerfile. Its an awesome tool for automatating and deployment and used to implement the concepts of "Continuous Delivery".
It simplifies the building and deployment process for the application. You can install the new version of the application in a Docker Container and just push the changes of Container to all your clients. You can do the same thing for changes in the infrastructure which is needed to run your application. Just deploy the changes.