I'm testing this using an insecure docker registry running on my local machine.
To run the local registry:
docker run -d -p 5000:5000 --name registry-srv -e REGISTRY_STORAGE_DELETE_ENABLED=true registry:2
docker run -it -p 8080:8080 --name registry-web --link registry-srv -e REGISTRY_URL=http://registry-srv:5000/v2 -e REGISTRY_NAME=localhost:5000 hyper/docker-registry-web
kaniko can't push to 'localhost:5000' so we need to substitute the host's IP address into ./config.json and the command below, which uses kaniko to build and push it:
docker run -v $PWD:/workspace -v $PWD/config.json:/kaniko/config.json --env DOCKER_CONFIG=/kaniko gcr.io/kaniko-project/executor:latest -d 9.140.99.106:5000/mnuttall/simple --insecure
One can then
docker run -p 8081:8081 localhost:5000/mnuttall/simple
and then point a browser to localhost:8081. Obviously it's easier to use docker build but we're trying to wean ourselves off that in this example. Note that the password in 'config.json' is just to keep kaniko happy; it's not a real password.
To delete localhost:5000/mnuttall/simple/latest:
curl -i -H "Accept: application/vnd.docker.distribution.manifest.v2+json" http://localhost:5000/v2/mnuttall/simple/manifests/latest
curl -X "DELETE" http://localhost:5000/v2/mnuttall/simple/manifests/sha256:c6c92e4ddef0304101fb47c85390ef8a46048a3615fb077d8ce9c985736cb89d
Where 'sha256:c6c92e4ddef0304101fb47c85390ef8a46048a3615fb077d8ce9c985736cb89d' is the value of the Docker-Content-Digest header in the response to the previous HTTP GET.