Vector Packet Processing 103: Ligato & VPP Agent

Welcome back to our guide on Vector Packet Processing. In today’s post number three from our VPP series, we will take a look at Ligato and the its VPP Agent.

Ligato is one of multiple commercially supported technologies supported by PANTHEON.tech.

What is a VNF?

A Virtual Network Function is a software implementation of a function. It runs on single or multiple Virtual Machines or Containers, on top of a hardware networking infrastructure. Individual functions of this network may be implemented or combined together, in order to create a complete networking communication service. A VNF can be used as a standalone entity or part of an SDN architecture.

Its life-cycle is controlled by orchestration systems, such as the increasingly popular Kubernets. Cloud-native VNFs and their control/management plane can expose REST or gRPC APIs to external clients, communicate over a message bus or provide a cloud-friendly environment for deployment and usage. It can also support high-performance data planes, such as VPP.

What is Ligato?

It is the open source cloud platform for building and wiring VNFs. Ligato provides infrastructure and libraries, code samples and CI/CD process to accelerate and improve the overall developer experience. It paves the way towards faster code reuse, reducing costs and increasing application agility & maintainability. Being native to the cloud, Ligato has a minimal footprint, plus can be easily integrated, customized and extended, deployed using Kubernetes. The three main components of Ligato are:

  • CN Infra – a Golang platform for developing cloud-native microservices. It can be used to develop any microservice, even though it was primarily designed for Virtual Network Function management/control plane agents.
  • SFC Controller – an orchestration module for data-plane connectivity within cloud-native containers. These containers may be VPP-Agent enabled or communicate via veth interfaces.
  • BGP Agent – a Border Gateway Protocol information provider. You can also view a Ligato demonstration done by PANTHEON.tech here.

The platform is modular-based – new plugins provide new functionality. These plugins can be setup in layers, where each layer can form a new platform with different services at a higher layer plane. This approach mainly aims to create a management/control plane for VPP, with the addition of the VPP Agent.

What is the VPP Agent?

The VPP Agent is a set of VPP-specific plugins that interact with Ligato, in order to access services within the same cloud. VPP Agent provides VPP functionality to client apps through a VPP model-driven API. External and internal clients can access this API, if they are running on the same CN-Infra platform, within the same Linux process. 

Quickstarting the VPP Agent

For this example, we will work with the pre-built Docker image.

Install & Run

  1. Run the downloaded Docker image:

    docker pull ligato/vpp-agent
    docker run -it --name vpp --rm ligato/vpp-agent
  2. Using agentctl, configure the VPP Agent:

    docker exec -it vpp agentctl -
  3. Check the configuration, using agentctl or the VPP console:

    docker exec -it vpp agentctl -e 172.17.0.1:2379 show
    docker exec -it vpp vppctl -s localhost:500

For a detailed rundown of the Quickstart, please refer to the Quickstart section of VPP Agents Github.

We have shown you how to integrate and quickstart the  VPP Agent, on top of Ligato.

Our next post will highlight gRPC/REST – until then, enjoy playing around with VPP Agent.


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