Docker image format
I would like to build a Docker image without docker iself. I have looked at Packer , but it requiers to have Docker installed on the builder host. I have looked at the Docker Registry API documentation but this information doesn't appear to be there. I guess that the image is simply a tarball, but I would like to see a complete specification of the format, i.e. what exect format is required and whethere there are any metadata files required. I could attempt downloading an image from the registry and look what's inside, but there is no information on how to fetch the image itself. The idea of