Running P4 on docker

Getting Started with P4
1

Hi everybody.
I’m new with P4 and I’m wondering if it’s possible to run a P4 program inside a docker container. I tried the GitHub - cslev/p4-bmv2-docker: P4 BMV2 docker container and Docker bmv2 containers, but it doesn’t have instructions about how the architecture should be deployed.
I was trying a simple example with 3 hosts running in containers and a BMV2 container acting as the main gateway with a simple p4 code that drop all the traffic to one specific container, allowing the communication between the other two.
It is possible to do such scenario? Someone have some reference that could help me to understand how to implement this kind of solution? Thank you so much!

2

Hi @dnredson

you can do that, here the official docker hub repo of the BMV2 switch Docker.
here a command example:
sudo docker run --privileged --net=host --rm -it --name bmv2 -d docker_image_name simple _switch_grpc --device-id 1 -i 1@v1 -i 2@v2 -i 4@v3 -i 3@v4 -i 5@v5 --thrift-port 9090 -Ldebug --no-p4 -- --cpu-port 255 --grpc-server-add 0.0.0.0:50001

This flags are docker commands: sudo docker run:

  • --privileged : It enables Docker containers to access all devices located under the /dev directory on the host machine
  • --net=host : is a networking mode in which a Docker container shares its network namespace with the host machine .
  • --rm: The ‘docker rm’ command removes or deletes Docker containers when is stopped
    *-it: creating an interactive bash shell in the container
  • --name pick_a_docker_name : you can provide a meaningful identifier for your container
  • -d : run the container detached

Those are the classics flags that you use for running a bmv2 switch (in this case i’m running a grpc simple switch simple _switch_grpc --device-id 1 -i 1@v1 -i 2@v2 -i 4@v3 -i 3@v4 -i 5@v5 --thrift-port 9090 -Ldebug --no-p4 – --cpu-port 255 --grpc-server-add 0.0.0.0:50001`) like the one that you can see there GitHub - p4lang/behavioral-model: The reference P4 software switch.

3

Thank you so much for the response!
I used the suggested docker image and created 3 interfaces veth (veth0, veth1, veth2, veth3), one connected to the switch and the other 3 for each container.
After that, started the switch with the interfaces as sugested: -i 1@veth1 -i 2@veth2 -i 3@veth3 -i 4@veth0
Started the switch and for each entry, created the command as this example:
table_add MyIngress.ipv4_lpm ipv4_forward 10.0.0.3 => fa:f9:6b:05:4c:08 3

Also, on each docker container, I created a route pointing the bmv2 as the default gw, but it has seen snot work yet. There is any other documentation that treat the deployment using docker, detailing the network configuration? I created the network as host, but still not being able to make the bmv2 docker to run properly.
Does anyone ever tried something like that?

4

Hi can you provide and image of the topology?

5

Hi Davide,
I’m trying to create something like that:

topology
topology868×574 12.5 KB

Use the bmv2 switch to control the docker network. And then, try to do two experiments, the first is a simple firewall that blocks any traffic to or from 10.0.0.3 and the second is to clone packets to two different hosts. But this topology illustrated is not working yet.

6

Hi @dnredson

  1. Did tou try to sniff packets on the bmv2 interfaces
  2. What did you get if you run the simple _switch with the flag --log-console, this command allow you to see what is is going on in the pipeline.