P4Runtime-enabled Mininet Docker Image

Docker image that can execute a Mininet-emulated network of BMv2 virtual switches, controlled by an external SDN controller via P4Runtime.

This image was created to facilitate testing of P4Runtime support in the ONOS controller, but you can use it without ONOS.

To obtain the image:

docker pull opennetworking/p4mn:<tag>

Tags

The image comes in two versions (tags):

• opennetworking/p4mn:latest Updated daily and built from the master branch of the BMv2 and PI (P4Runtime server implementation) repositories;
• opennetworking/p4mn:stable Built using selected BMv2 and PI versions that are known to work well with ONOS master.

Moreover, each tag is available in a "no-logging" version with disabled logging macros in BMv2 to improve packet forwarding performance:

• opennetworking/p4mn:latest-no-logging
• opennetworking/p4mn:stable-no-logging

Status

Images are built daily using [Github Actions][GH Actions] and pushed to Docker Hub.

Steps to run p4mn

To run the container:

docker run --privileged --rm -it opennetworking/p4mn [MININET ARGS]

After running this command, you should see the mininet CLI (mininet>).

It is important to run this container in privileged mode (--privileged) so mininet can modify the network interfaces and properties to emulate the desired topology.

The image defines as entry point the mininet executable configured to use BMv2 simple_switch_grpc as the default switch. Options to the docker run command ([MININET ARGS]) are passed as parameters to the mininet process. For more information on the supported mininet options, please check the official mininet documentation.

For example, to run a linear topology with 3 switches:

docker run --privileged --rm -it opennetworking/p4mn --topo linear,3

P4Runtime server ports

Each switch starts a P4Runtime server which is bound to a different port, starting from 50001 and increasing. To connect an external P4Runtime client (e.g. an SDN controller) to the switches, you have to publish the corresponding ports.

For example, when running a topology with 3 switches:

 docker run --privileged --rm -it -p 50001-50003:50001-50003 opennetworking/p4mn --topo linear,3

BMv2 logs and other temporary files

To allow easier access to BMv2 logs and other files, we suggest sharing the /tmp directory inside the container on the host system using the docker run -v option, for example:

docker run ... -v /tmp/p4mn:/tmp ... opennetworking/p4mn ...

By using this option, during the container execution, a number of files related to the execution of the BMv2 switches will be available under /tmp/p4mn in the host system. The name of these files depends on the switch name used in Mininet, e.g. s1, s2, etc.

Example of these files are:

• bmv2-s1-grpc-port: contains the port used for the P4Runtime server executed by the switch instance named s1;
• bmv2-s1-log: contains the BMv2 log;
• bmv2-s1-netcfg.json: ONOS netcfg JSON file that can be pushed to ONOS to discover this switch instance. This file assumes that ONOS is running on the same host as the container. If this is not the case, you will need to modify the managementAddress property in the JSON file, replacing localhost with the IP address of the host system of the p4mn container.

Bash alias

A convenient way to quickly start the p4mn container is to create an alias in your bash profile file (.bashrc, .bash_aliases, or .bash_profile) . For example:

alias p4mn="rm -rf /tmp/p4mn && docker run --privileged --rm -it -v /tmp/p4mn:/tmp -p50001-50030:50001-50030 --name p4mn --hostname p4mn opennetworking/p4mn"

Then, to run a a simple 1-switch 2-host topology:

$ p4mn
*** Creating network
*** Adding controller
*** Adding hosts:
h1 h2
*** Adding switches:
s1
*** Adding links:
(h1, s1) (h2, s1)
*** Configuring hosts
h1 h2
*** Starting controller

*** Starting 1 switches
s1 ....⚡️ simple_switch_grpc @ 50001

*** Starting CLI:
mininet>

Or a linear one with 3 switches and 3 hosts:

$ p4mn --topo linear,3
*** Creating network
*** Adding controller
*** Adding hosts:
h1 h2 h3
*** Adding switches:
s1 s2 s3
*** Adding links:
(h1, s1) (h2, s2) (h3, s3) (s2, s1) (s3, s2)
*** Configuring hosts
h1 h2 h3
*** Starting controller

*** Starting 3 switches
s1 .....⚡️ simple_switch_grpc @ 50001
s2 .....⚡️ simple_switch_grpc @ 50002
s3 .....⚡️ simple_switch_grpc @ 50003

*** Starting CLI:
mininet>