Submariner Globalnet Support with OVN-Kubernetes CNI

[astoycos]

Epic Description

The current implementation of Globalnet Controller works with iptables based kubeproxy. We have to add support for clusters that use OVN as the network-plugin driver.

Acceptance Criteria

The Globalnet feature functions correctly when using Submariner with the OVN-Kubernetes CNI.

Definition of Done (Checklist)

• Code complete
• Relevant metrics added
• The acceptance criteria met
• Unit/e2e test added & pass
• CI jobs pass
• Deployed using cloud-prepare+subctl
• Deployed using ACM/OCM addon
• Deploy using Helm
• Deployed on supported platforms (for e.g kind, OCP on AWS, OCP on GCP)
• Run subctl verify, diagnose and gather
• Uninstall
• Troubleshooting (gather/diagnose) added
• Documentation added
• Release notes added

Work Items

• Enhancement PR: Globalnet support for OVN Kubernetes deployments
• Missing rule in SUBMARINER-POSTROUTING chain
• Missing default route in table 150 on all the worker nodes
• Redirect the ingress traffic to a cluster via the submariner_router
• Fix logical routes programmed in submariner_router
• Race condition in ovn routeagent handler
• Documentation

[maayanf24]

Only item left to do is documentation

[sridhargaddam]

Documentation is updated as part of the following PR: submariner-io/submariner-website#830