feat: Support for static AzureCNI without overlay networking via generating additional ip configurations

[Bryce-Soghigian]

Fixes #367

Description This PR adds support for azure cni without overlay, as well as introduces some makefile goodness for creating clusters or other cni configurations.

Why Do We Need Secondary IP Configs For AZ CNI Without Overlay?

When a pod is created, the Azure CNI plugin allocates an IP address from the pool of secondary IP addresses configured on the NIC of the node where the pod is scheduled. The Azure CNI plugin manages the allocation and de-allocation of these IP addresses through the IP Address Manager (IPAM), ensuring each pod receives a unique IP address and tracking the usage of these addresses.

In this setup, pods are assigned IP addresses from the node's subnet, allowing for direct IP connectivity. This enables pods within the same virtual network to communicate without the need for Network Address Translation (NAT). The node's NIC routes traffic to the appropriate pod based on the assigned IP.

Flow

1. Node NIC: Primary IP and multiple secondary IP addresses are assigned to the nic on node creation, and the nic is assigned to the node
2. Pod Create: Pod requests an IP address on intialization
3. Azure CNI Plugin: Assigns a secondary IP to the pod from the node’s NIC.
4. Network Interface within Node: We use transparent mode, which doesn't change any properties of the eth0 interface on the nic. Azure CNI creates and adds host-side pod veth pair interfaces that are added to the host network.
5. Pod to Pod Communication: Pods communicate using their assigned IPs directly within the virtual network. Pod to Pod communication is over layer 3 and L3 routing rules route the pod traffic.

Learn more about specifics here

How was this change tested?

• e2e tests
• unit tests
• manual scale ups and goldpinger

What this PR does not include

• E2E Suite for our Upstream E2Es here testing other network connectivity(ingress + egress)
• Port of our E2Es to run fully each time on azure cni without overlay Does this change impact docs?
• [ ] Yes, PR includes docs updates
• [ ] Yes, issue opened: #
• [ ] No

Release Note

support added for static AzureCNI without overlay networking

[coveralls]

Pull Request Test Coverage Report for Build 9359164104

Details

• 102 of 105 (97.14%) changed or added relevant lines in 8 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.003%) to 97.777%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/utils/cni.go	7	8	87.5%
pkg/providers/launchtemplate/launchtemplate.go	9	11	81.82%
<!--	Total:	102	105	97.14%	-->

Totals
Change from base Build 9074172591:	0.003%
Covered Lines:	36334
Relevant Lines:	37160

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💛 - Coveralls

[Bryce-Soghigian]

Still figuring out a bug in the make ci-non-test commands for new files its generating the boilerplate twice. But this should be ready for review @charliedmcb @tallaxes