Some CNIs support the advertisement of service IPs into BGP, which may
provide an alternative to managing the VIP as an interface on the host.
This change adds an option to assign the ingress VIP as an externalIP to
the ingress service. For example:
network:
vip:
manage: false
addr: 172.18.0.1/32 # (with or without subnet mask)
assign_as_external_ip: true
Change-Id: I1eeb07a1f94ef8efcb21f3373e0d5f86be725b33
3a10c5ba95