问题:

When I mistype things it tries to search in the central registry. How to disable it completely?

Is there an option to clear that URL?

回答1:

If you use the a redhat clone with the rpms from centos extras, they have a parameter to do that:

--block-registry hostname

This is a RedHat extension (see here) which I don't think was accepted upstream (considering 13450)

As a reference, right now (docker 1.9, Nov 2015):

pull.go looks for pull endpoints:

s.registryService.LookupPullEndpoints()

registry/service.go looks for V2 endpoint:
```
s.lookupEndpoints(repoName)
```

registry/service_v2.go appends DefaultV2Registry:

endpoints = append(endpoints, APIEndpoint{
    URL:          DefaultV2Registry,

registry/config_unix.go includes DefaultV2Registry:

DefaultV2Registry = "https://registry-1.docker.io"

So until there is an option to not look for that endpoint, docker pull will still include that central default V2 registry.