Blixt DataPlane

In this directory you'll find the data-plane code for Blixt. The extended Berkeley Packet Filter (eBPF) available in the Linux Kernel is used as the data-plane to support TCP and UDP ingress.

Overview

In this directory you'll find the following sub-directories:

• common - shared libraries with common types and tools
• ebpf - this is where eBPF code lives which programs routes into the Kernel
• loader - a userland program which loads the eBPF code into the Kernel
• api-server - a gRPC API where configuration changes are pushed

This enables serving TCP and UDP ingress traffic.

The data-plane normally is programmed by pairing it with the control-plane, using TCPRoute and UDPRoute APIs in Kubernetes, however as is mentioned above it is possible to program it directly via the gRPC client if needed for development/testing.

Note: Before the gRPC API the data-plane used to pull configuration from the Kubernetes API instead of the configuration being pushed. The current way of doing things was done because it helped make development and debugging easier in the interim, but we expect in time to drop the gRPC API and move back to a Kubernetes controller design.

Development

First you'll need to create a Kubernetes cluster (with kind):

make build.cluster

With that cluster from here on, you can make your changes locally, and then build and push those changes to the cluster with:

make load.image.dataplane TAG=latest

This will build the container image, and load it into the cluster.

Then deploy the manifest, which will create the DaemonSet which uses the image you just loaded in the cluster:

kubectl kustomize config/dataplane | kubectl apply -f -

From here on out, any time you want to push your new changes to the cluster all you have to do is re-run:

make load.image.dataplane TAG=latest

This will build the image, load the image, and perform a rollout to restart the Pods with the new image.

To push test configurations to the data-plane you can use the xtask provided in this directory which includes a grpc-client command for manually sending data-plane configuration to the data-plane's gRPC API.

To view the documentation for this, run:

cargo xtask grpc-client --help

Note: You can alternatively deploy the control-plane to develop and test as well, which is helpful anyhow as any changes made here need to be reflected in the control-plane code eventually anyway.