Description of the Problem

I have seen inline issue during OSD cluster creation with older OCP version. After further analysis it seems like related to the recent change in cluster autoscaler max node count limit.

I have tried to create an OSD (non CCS) cluster with version < 4.14.14 from OCM UI and cluster creation fails with inline error. It looks the issue could be, the UI sending the max nodes total value always 249 and the backend has the restriction based on the cluster version.

This looks wrong  and probably UI doesn't respect the criteria on max-nodes-total value from Cluster autoscaling i.e. max-nodes-total "180 for clusters below Openshift v14.14.14"

Consequences of current behavior.

1. User can't create a OSD (non CCS) cluster creation with version <4.14.14 along with autoscaling enabled feature. Backend always throws the above error and blocks the cluster creation. User even can't change the cluster autoscaling default values (ex: max node total) from UI for OSD non CCS flow.
2. Same situation applicable for OSD CCS clusters as well but there is workaround to overcome this. i.e. User could go to "Edit cluster autoscaling" option in  wizard step and change the default value of max node total from 249 to 180. 

How reproducible:

always

Steps to Reproduce:

1. Open OCM UI staging.
2. Open OSD wizard.
3. In billing model step, make following selection
   1. Subscription type as Annual: Fixed capacity subscription from Red Hat
   2. Infrastructure type as Red Hat cloud account
4. Click "Next"  and select cloud provider "AWS" or "GCP"
5. Click "Next", select cluster version < 4.14.14 and fill other required fields.
6. Click "Next", In default machine pool step, enable "Enable autoscaling" checkbox.
7. Proceed to next steps.
8. Click "Create cluster" from "Review and create" step and see the behavior.

Actual results:

The cluster creation blocked from UI with backend error as mentioned above.

Expected results:

The cluster creation shouldn't be blocked from UI with supported OCP version (including older OCP version). The ideal solution would be , when OCP version < 14.14.14 selected from wizard then set the max node total value to 180 instead of 249.