What is Dockerfile
Docker can build images automatically by reading the instructions from a file called Dockerfile. A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.
How cloud 66 uses the Dockerfile
For Cloud 66 to be able to create a docker image from your source code, you need to put a file called Dockerfile (the name has to be exactly the same) in the root of your git repository!