code: func getAuthSettings() (gophercloud.AuthOptions, error) {
  	remapEnv(map[string]string{
  		"OS_TENANT_NAME": "OS_PROJECT_NAME",
  		"OS_TENANT_ID":   "OS_PROJECT_ID",
  		"OS_DOMAIN_NAME": "OS_USER_DOMAIN_NAME",
  		"OS_DOMAIN_ID":   "OS_USER_DOMAIN_ID",
  	})
  
  	opts, err := openstack.AuthOptionsFromEnv()
  	if err != nil {
  		return gophercloud.AuthOptions{}, err
  	}
  	opts.AllowReauth = true
  	if !strings.HasSuffix(opts.IdentityEndpoint, "/") {
  		opts.IdentityEndpoint += "/"
  	}
  	if !strings.HasSuffix(opts.IdentityEndpoint, "/v2.0/") && !strings.HasSuffix(opts.IdentityEndpoint, "/v3/") {
  		opts.IdentityEndpoint += "v2.0/"
  	}
  	return opts, nil
  }
docs: // returns OpenStack Keystone authentication settings by obtaining values from standard environment variables.
  // also fixes incompatibilities between gophercloud implementation and *-stackrc files that can be downloaded
  // from OpenStack dashboard in latest versions