Allow installer to enable global access in GCP

1. Proposed title of this feature request

• Allow installer to enable global access to the internal Ingress Load Balancer

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

• Allow installer to enable global access. 
• Enabling global access in Ingress operator is worked through RFE-1208

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

• Customer wants to enable this option in the installer. 

Customer would like the following to be added in line #51 in this file https://github.com/openshift/installer/blob/master/data/data/gcp/network/lb-private.tf#L51

:

allow_global_access   = true

 ** 

This is needed because without this change customer needs to update this two ILB’s created by OCP IPI for GCP are regional by default i.e. even though customer peers with Google network using “interconnect attachments”, these peering are defined in a different region and OCP cluster is deployed in another region, as per this GCP docs (https://cloud.google.com/load-balancing/docs/internal#client_access_2), we will not be able to reach either of these two endpoints in GCP:

1. API Servers (this will be addressed via another RFE)
2. OpenShift Console

Customer complied a custom “openshift-install” binary and another other option we did validate is deploy a bastion host in same region as the cluster itself is in and then deploy OCP from that bastion instead of our laptops, subsequently post cluster stand up we run these command correct ILBs:

gcloud compute forwarding-rules list -filter="region${GCP_REGION})" -format="csv[no-heading](name)" | \
awk '{print "gcloud compute forwarding-rules update "$1 " --region='${GCP_REGION}' --allow-global-access"}'

 7. Is there already an existing RFE upstream or in Red Hat Bugzilla?

• No, I could not find one.

8. Does the customer have any specific timeline dependencies and which release would they like to target?

• OCP 4.8

9. Is the sales team involved in this request and do they have any additional input? No

10. List any affected packages or components.

• openshift installer

11. Would the customer be able to assist in testing this functionality if implemented?

• Yes