1. Proposed title of this feature request

Validate minimum prerequisites of installation using `openshift-install` tool.
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Ex: $openshift-install validate install-config

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2. What is the nature and description of the request?

With CEE support, we have observed that around 50% of cases around
installation are reported for failure where the resolution happens to be
"insufficient" or "Not meeting the pre-requestisites".

Ex:

1. DNS records needed aren't in place.
2. Minimum system requirements specified in install-config.yaml aren't as per guidelines.
3. BMH/BMC aren't accessible.
4. Vsphere/Nutanix credentials aren't correct or permissions aren't available.
5. Azure/AWS credentials/permissions or roles aren’t in place.
6. Install-config.yaml syntax and indentation error.

Similar kind of issues with cloud platforms.
 

Which further categorized as,

• Early failure
• Mid install failure.

This failures are detected mostly in the mid phase of installation where it
needs logs gathering and investigating it, sometimes the logs aren't that
sufficient so support engineers do manual check for each of the
pre-requestisite as per documentation.  This consumes time and efforts from
both ends, customer and support engineers have to do trial-hit installs to
determine the resolution most of the time.

I feel this all can be clubbed together with the code merging as option to
have the validation based on the install-config.yaml file.

For 

Ex: 1 Validation of permissions.

From install-config.yaml I can know the platform and then can validate the
permission of the user using Vcenter Vsphere api for permissions as per doc
and dns records, similarly access to datastore availability of free IP's in
case of IPI install etc etc.

Ex:  2 Validation of DNS records for API , API-INT

From the install-config it shall check if the IP and DNS records match for the
api or api-int present.

3. Why does the customer need this? (List the business requirements here)

This impacts as below,

• Customers would be able to validate the install-config.yaml at their own and
    do the required changes which minimizes the failure at the time of install,
    resulting low count of case opening or reaching to support.

• For support engineers, time saving and a great to troubleshoot and validate
    the infra, releasing the burden of investigation/troubleshooting.

4. List any affected packages or components.

openshift-installer.