ipam

Overview ¶

Package ipam provides node-local IPAM calculations: POD IP addresses, VPP-host interconnect and node interconnect IP addresses.

The IP assignment is driven by unique node ID (uint32), that is passed to the IPAM module upon its initialization, together with IPAM configuration (can be specified as IPAMConfig in contiv-agent-cfg ConfigMap in ../../k8s/contiv-vpp.yaml). The contiv-agent on each node in the k8s cluster therefore does its node-local IPAM calculation and assignment itself, the cluster IPAM is therefore distributed between all nodes.

The package calculates and assigns the following IP addresses:

• node-local POD network and individual POD IPs (based on PodSubnetCIDR, PodNetworkPrefixLen and node ID)
• IP subnet for the VPP-to-host Linux stack interconnect (based on VPPHostSubnetCIDR, VPPHostNetworkPrefixLen and node ID)
• IP address of the physical interface used for node interconnect (based on NodeInterconnectCIDR and node ID)

Example:

	    IPAMConfig:
		  PodSubnetCIDR: "10.1.0.0/16"
		  PodNetworkPrefixLen: 24
		  VPPHostSubnetCIDR: "172.30.0.0/16"
		  VPPHostNetworkPrefixLen: 24
		  NodeInterconnectCIDR: "192.168.16.0/24"

		Assigned node ID: 5

		Calculated POD IPs: 10.1.5.2 - 10.1.5.254 (/24)
		Calculated VPP-host interconnect IPs: 172.30.5.1, 172.30.5.2 (/24)
 	Calculated Node Interconnect IP:  192.168.16.5 (/24)

Additionally the package provides REST endpoint for getting some of IPAM informations from node on URL GET /contiv/v1/ipam.

Example:

$ curl localhost:9999/contiv/v1/ipam
{
  "nodeId": 1,
  "nodeName": "vagrant-arch.vagrantup.com",
  "nodeIP": "192.168.16.1",
  "podNetwork": "10.1.1.0/24",
  "vppHostNetwork": "172.30.1.0/24"
}