code: func (g *dockerConfigUrlKeyProvider) Provide(image string) credentialprovider.DockerConfig {
  	// Read the contents of the google-dockercfg-url key and load a .dockercfg from there
  	if url, err := credentialprovider.ReadUrl(dockerConfigUrlKey, g.Client, metadataHeader); err != nil {
  		klog.Errorf("while reading 'google-dockercfg-url' metadata: %v", err)
  	} else {
  		if strings.HasPrefix(string(url), "http") {
  			if cfg, err := credentialprovider.ReadDockerConfigFileFromUrl(string(url), g.Client, nil); err != nil {
  				klog.Errorf("while reading 'google-dockercfg-url'-specified url: %s, %v", string(url), err)
  			} else {
  				return cfg
  			}
  		} else {
  			// TODO(mattmoor): support reading alternate scheme URLs (e.g. gs:// or s3://)
  			klog.Errorf("Unsupported URL scheme: %s", string(url))
  		}
  	}
  
  	return credentialprovider.DockerConfig{}
  }
docs: // Provide implements DockerConfigProvider