Description of problem:

When the cluster name matches neither cluster name rule nor domain rule, the error message is confused cause subdomain validation is ahead of cluster name validation in below function. As the gcp cluster name rule is subset of domain rule. For better user experience, I suggest to move gcp cluster name validation ahead of subdomain validation. Please check out below code

 27 func (a *clusterName) Generate(parents asset.Parents) error {
 28         bd := &baseDomain{}
 29         platform := &platform{}
 30         parents.Get(bd, platform)
 31 
 32         validator := survey.ComposeValidators(survey.Required, func(ans interface{}) error     {
 33                 return validate.DomainName(validation.ClusterDomain(bd.BaseDomain, ans.(str    ing)), false)
 34         })
 35         if platform.GCP != nil {
 36                 validator = survey.ComposeValidators(validator, func(ans interface{}) error     { 
                    return gcpvalidation.ValidateClusterName(ans.(string)) })
 37         }
 38 
 
"pkg/asset/installconfig/clustername.go" 53 lines --50%-- 


Version-Release number of the following components:

4.3.0-0.nightly-2019-12-24-014531

How reproducible:
100%

Steps to Reproduce:

# openshift-install create install-config --dir=test
? Platform gcp
? Cluster Name [? for help] a123-


Actual results:

X Sorry, your reply was invalid: a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')


Expected results:

X Sorry, your reply was invalid: GCP requires cluster name to match regular expression (?:[a-z](?:[-a-z0-9]{0,61}[a-z0-9])?)

Additional info:
Please attach logs from ansible-playbook with the -vvv flag