Kubernetes Network Emulation
This is not an officially supported Google product.
Goal
For network emulation, there are many approaches using VM's for emulation of a
hardware router. Arista, Cisco, Juniper, and Nokia have multiple implementations
of their network operating system and various generations of hardware emulation.
These systems are very good for most validation of vendor control plane
implementations and data plane for limited certifications. The idea of this
project is to provide a standard "interface" so that vendors can produce a
standard container implementation which can be used to build complex topologies.
- Have standard lifecycle management infrastructure for allowing multiple vendor
device emulations to be present in a single "topology"
- Allow for control plane access via standard k8s networking
- Provide a common networking interface for the forwarding plane between network
pods.
- Data plane wires between pods
- Control plane wires between topology manager
- Define service implementation for allowing interaction with the topology
manager service.
- Topology manager is the public API for allowing external users to manipulate
the link state in the topology.
- The topology manager will run as a service in k8s environment.
- It will provide a gRPC interface for tests to interact with
- It will listen to CRDs published via the network device pods for discovery
- Data plane connections for connectivity between pods must be a public
transport mechanism
- This can't be implemented as just exposing "x eth devices on the pod"
because Linux doesn't understand the associated control messages which are
needed to make this work like a wire.
- Transceiver state, optical characteristics, wire state, packet filtering /
shaping / drops
- LACP or other port aggregation protocols or APS cannot be simulated
correctly
- The topology manager will start a topology agent on each host for the pod to
directly interact with.
- The topology agent will provide the connectivity between nodes
- Define how pods boot an initial configuration
- Ideally, this method would allow for dynamic
- Define how pods express services for use in-cluster as well as external
services
Use Cases
Test Development
The main use case of this infrastructure is for the development of tests to
validate control plane / configuration of network devices without needing real
hardware.
The main use case we are interested in is the ability to bring up arbitrary
topologies to represent a production topology. This would require multiple
vendors as well as traffic generation and end hosts.
In support of the testing we need to be able to provide every tester, engineer
and continuous automated run a set of environments to validate test scenarios
used in production. These can also be used to pre-validate hardware testing as
well. This can reduce cycle time as there will be no contention for the virtual
testbed vs. the hardware testbed. This also allows for "unit testing" the
integration test.
Software Development
For the development of new services or for offering a better environment to
developers for existing services, virtual testbeds would allow for better
scaling of resources and easier to use testbeds that would be customized for a
team's needs. Specifically, workflow automation struggles to have physical
representations of metros that need to be validated for workflows. A virtual
testbed would allow for the majority of workflows to be validated against any
number of production topologies.
Usage
See the collection of docs for in depth guides on how use
Kubernetes Network Emulation (KNE).
Thanks
This project is mainly based on the k8s-topo from github.com/networkop/k8s-topo
and meshnet-cni plugin from github.com/networkop/meshnet-cni.