Feature Overview (aka. Goal Summary)  

Problem 1

• Networking features has to be explicitly configured and that needs to be on the management cluster.
• Not all fields and options on Network.config.openshift.io can be configured on HCP APIs today.
   

• We need to provide a way for customers to do that. 

Problem 2

• Some features in Network.operator.openshift.io would not work on HCP (no-op). Example: Hybrid Networking Configuration in OpenShift.
  • For example `internalJoinSubnet` and `internalTransitSwitchSubnet`

• We should identify those features, address or document them

Requirements (aka. Acceptance Criteria):

• The Ability for customers to configure fields relating to networking.config.openshift.io on exposed API (Hosted Cluster). 
• Features in network.config.openshift.io that do not work in HCP should be identified
• Features in network.config.openshift.io that do not work in HCP should implemented (and delegated as dependencies if needed). 

Deployment Considerations

 Additional Context

Overview:

Customers of HCP and ROSA-HCP will want to be able to configure:

1. IPSec (full mode) for node-to-node networking
2. The OVN CIDR network - to avoid collision with already used CIDRs.

These will unblock customers who have strict requirements for these features.

Requirements:

ROSA-HCP (hosted cluster) clusters need to offer the following configurables to customers as available in OCP:

• Allow customers to customize OVN internal subnet CIDRs: internalTransitSwitchSubnet & internalJoinSubnet
• Allow customers to connect VPC hosting ROSA clusters with other VPCs already using CIDRs 100.88.0.0/16 and/or 100.64.0.0/16
• ensure changes are in place to accomodate the acceptance criteria in XCMSTRAT-961
  • Ability to configure this both during cluster creation (create cluster) and post cluster creation (edit cluster)
  • Customers are required an acknowledgement if worker nodes will be rebooted
  • Configurations to modify is not simultaneously allowed when a cluster update is either in progress or scheduled
  • Ensure the machine CIDR and V4InternalSubnet fields are different
  • Existing preflight for these CIDR ranges' use in MachineCIDR is removed 
    network-verifier is adjusted for any validations
  • Ability to configure only on versions OCP 4.16+