Networking

Kubermatic-Virtualization uses KubeOVN as a software defined network(SDN) and it supercharges Kubernetes networking by integrating it with Open Virtual Network (OVN) and Open vSwitch (OVS). These aren’t new players; OVN and OVS are long-standing, industry-standard technologies in the Software-Defined Networking (SDN) space, predating Kubernetes itself. By leveraging their robust, mature capabilities, Kube-OVN significantly expands what Kubernetes can do with its network.

VPC

A VPC (Virtual Private Cloud) in Kube-OVN represents an isolated layer-3 network domain that contains one or more subnets. Each VPC provides its own routing table and default gateway, allowing you to logically separate network traffic between tenants or workloads.

Kubermatic Virtualization simplifies network setup by providing a default Virtual Private Cloud (VPC) and a default Subnet right out of the box. These are pre-configured to connect directly to the underlying node network, offering a seamless link to your existing infrastructure. This means you don’t need to attach external networks to get started.

This design is a huge win for new users. It allows customers to dive into Kubermatic Virtualization and quickly establish network connectivity between their workloads and the hypervisor without wrestling with complex network configurations, external appliances, or advanced networking concepts. It’s all about making the initial experience as straightforward and efficient as possible, letting you focus on your applications rather than network plumbing.

Here is an example of a VPC definition:

apiVersion: kubeovn.io/v1
kind: Vpc
metadata:
  name: custom-vpc
spec:
  cidr: 10.200.0.0/16
  enableNAT: false
  defaultGateway: ""
  staticRoutes:
    - cidr: 0.0.0.0/0
      nextHopIP: 10.200.0.1

Subnet

Subnets are the fundamental building blocks for network and IP management. They serve as the primary organizational unit for configuring network settings and IP addresses.

• Namespace-Centric: Each Kubernetes Namespace can be assigned to a specific Subnet.
• Automatic IP Allocation: Pods deployed within a Namespace automatically receive their IP addresses from the Subnet that Namespace is associated with.
• Shared Network Configuration: All Pods within a Namespace inherit the network configuration defined by their Subnet. This includes:
  • CIDR (Classless Inter-Domain Routing): The IP address range for the Subnet.
  • Gateway Type: How traffic leaves the Subnet.
  • Access Control: Network policies and security rules.
  • NAT Control: Network Address Translation settings.

Here is an example of a VPC definition:

apiVersion: kubeovn.io/v1
kind: Subnet
metadata:
  name: my-custom-subnet
  namespace: kube-system
spec:
  cidrBlock: 10.16.0.0/16
  gateway: 10.16.0.1
  gatewayType: distributed
  excludeIps:
    - 10.16.0.1
    - 10.16.0.2..10.16.0.10
  protocol: IPv4
  natOutgoing: true
  private: false
  vpc: custom-vpc
  enableDHCP: true
  allowSubnets: []
  vlan: ""
  namespaces:
    - default
    - dev
  subnetType: overlay