Where can I create images from? Locally at all? (Docker remote API) - image

Question

May/may not be an easy question here, but where can I pull images from to create a new docker image via the API?
Documentation
My (unsuccessful) attempts have been trying to build an image from something local. Using docker images to get a list of images, then trying to use their Image ID or Repository has not worked for me while using the fromImage query param like so:
curl --data '' host:port/images/create?fromImage=test/hello-world&tag=webTesting
I consistently get the following error:
{"errorDetail":{"message":"Error: image test/hello-world not found"},"error":"Error: image test/hello-world not found"}
In running docker images, we can very clearly see the following:
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
test/hello-world latest 6d9bd5e6da4e 2 days ago 556.9 MB
In all combinations of using the repository/tag/id the error still displays. I understand that we can create images from urls with fromSrc, and there are alternative create image routes by uploading .tar files, but is it possible in the case to create an image from one that already exists locally? I've had success in compiling images from ubuntu or centos, but I'm looking basically to replicate something local with new tags/repository.
I do see in the documentation that fromImage parameter may only be used when pulling an image -- does this mean we can only import images that are hosted on Dockerhub?

Answer 1

As you noted, the Docker remote API documentation clearly states that a pull operation must be triggered for this image reference.
This does not require that you use DockerHub, but it means that the image must be located on a registry and not simply in your daemon's local cache. If you were running a Docker registry instance on your host (which is easily done with the public registry image in DockerHub) on port 5000, then you could use "localhost:5000/test/hello-world" as the fromImage, and it will pull it from your locally hosted registry (after you push it locally of course).