anchor.diff:  * https://github.com/rpardini/docker-registry-proxy
   
   Once the caching registry is operating, pipelines can be updated to use images
  -from that registry (eg from `nginx:1.14.2` to `example.com/nginx:1.14.2`) and
  +from that registry (e.g. from `nginx:1.14.2` to `example.com/nginx:1.14.2`) and
   new images will be transparently fetched from Docker Hub.
  
positive.code: DOCKER_LOGIN_PASSWORD="the-password"
  ```
  
  ## Other Buuildkite agents authenticating with a paid Docker Hub account
  
  All agents check the local filesystem for [hook scripts to execute during a job](/docs/agent/v3/hooks).
  
  
negative.code: 
  This approach requires:
  
  1. A regular process (e.g. nightly) that mirrors the Docker images you need
  2. Updating all pipelines to use the mirrored GCR image (e.g. from `nginx:1.14.2`
     to `gcr.io/<GCR_PROJECT>/nginx:1.14.2`)
  
  ## Mirroring Docker images into AWS Elastic Container Registry
  