use expected MinIO URLs for console (#12770)

when TLS is configured using IPs directly
might interfere and not work properly when
the server is configured with TLS certs but
the certs only have domain certs.

Also additionally allow users to specify
a public accessible URL for console to talk
to MinIO i.e `MINIO_SERVER_URL` this would
allow them to use an external ingress domain
to talk to MinIO. This internally fixes few
problems such as presigned URL generation on
the console UI etc.

This needs to be done additionally for any
MinIO deployments that might have a much more
stricter requirement when running in standalone
mode such as FS or standalone erasure code.

cmd/endpoint.go

@@ -245,7 +245,7 @@ func (l *EndpointServerPools) Add(zeps PoolEndpoints) error {
 func (l EndpointServerPools) Localhost() string {
 	for _, ep := range l {
 		for _, endpoint := range ep.Endpoints {
-			if endpoint.IsLocal {
+			if endpoint.IsLocal && endpoint.Host != "" {
 				u := &url.URL{
 					Scheme: endpoint.Scheme,
 					Host:   endpoint.Host,
@@ -254,7 +254,11 @@ func (l EndpointServerPools) Localhost() string {
 			}
 		}
 	}
-	return ""
+	host := globalMinioHost
+	if host == "" {
+		host = sortIPs(localIP4.ToSlice())[0]
+	}
+	return fmt.Sprintf("%s://%s", getURLScheme(globalIsTLS), net.JoinHostPort(host, globalMinioPort))
 }
 
 // LocalDisksPaths returns the disk paths of the local disks