title: What is Docker URL
body: <p>I am building a gradle project in Jenkins. and client has asked to build the project in docker image. i am new to Jenkins and docker(i am able to build the project normally on Jenkins) i have installed the docker plugin and now it asks for <strong>DOCKER URL</strong> and <strong>Docker API</strong> under cloud settings.  what are those and how to configure the docker. i am running Jenkins on the remote server, which is setup by another person. i don't have access to shell command, i have to use docker and build the project, and what is <strong>dockerfile</strong> and how to build and what to put in it.</p>