AF_XDP Plugins for Kubernetes

A Kubernetes device plugin and CNI plugin to provide AF_XDP networking to Kubernetes pods. The plugins will have multiple modes of operation. Currently the only implemented mode is to provide AF_XDP networking to pods using Intel's Cloud Native Data Plane (CNDP) framework.

Prerequisites

Required

The following prerequisites are required to build and deploy the plugins:

• OS
  • Tested on Ubuntu 20.04.
• Docker
  • All recent versions should work. Tested on 20.10.5, 20.10.7, 20.10.12, 20.10.14.
  • Note: You may need to disable memlock on Docker. Add the following section to /etc/docker/daemon.json:

     "default-ulimits": {
     "memlock": {
     	"Name": "memlock",
     	"Hard": -1,
     	"Soft": -1
     	}
     }
    

    Restart the Docker service: systemctl restart docker.service
• Kubernetes
  • All recent versions should work. Tested on 1.20.2, 1.21.1, v1.22.4, v1.23.0, v1.23.5.
• A CNI network
  • To serve as the default network to the Kubernetes pods.
  • Any CNI should work. Tested with Flannel.
• Multus CNI
  • To enable attaching multiple network interfaces to pods.
  • Multus quickstart guide.
• GoLang
  • To build the plugin binaries.
  • All recent versions should work. Tested on 1.13.8, 1.15.15, 1.17, 1.17.1, 1.17.8, 1.18.
  • Download and install.
• Libbpf
  • To load and unload the XDP program onto the network device.
  • Install on Ubuntu 20.10+: apt install libbpf-dev
  • Older versions: Install from source.
• GCC Compiler
  • To compile the C code used to call on the BPF Library.
  • Install on Ubuntu: apt install build-essential
• Binutils
  • Used in archiving of C code object file.
  • Install on Ubuntu: apt install binutils

Development

The following static analysis, linting and formatting tools are not required for building and deploying, but are built into some of the Make targets and enforced by CI. It is recommended to have these installed on your development system.

• GoFmt
  • Applies standard formatting to Go code.
  • Supplied with GoLang.
• Go Vet
  • Examines Go source code and reports suspicious constructs.
  • Supplied with GoLang.
• Go Lint
  • A linter for Go source code.
  • Install: go get -u golang.org/x/lint/golint
  • Note: Deprecated, but still useful in day to day development as a quick check
• GolangCI-Lint
  • A Go linters aggregator.
  • Install: curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.42.1
• Hadolint
  • A Dockerfile linter that helps build best practice into Docker images.
  • Runs in Docker container.
• Shellcheck
  • A static analysis tool for shell scripts.
  • Install on Ubuntu: apt install shellcheck
• Clang Format
  • Applies standard formatting to C code.
  • Install on Ubuntu: apt install clang-format
• CLOC
  • Count Lines Of Code, counts lines of code in many programming languages.
  • Install on Ubuntu: apt install cloc

Build and Deploy

• Clone this repo and cd into it.
• Optional: Update configuration. See Device Plugin Config.
• Run make deploy.

The following steps happen automatically:

1. make build is executed, resulting in CNI and Device Plugin binaries in ./bin.
2. make image is executed, resulting in the creation of a new Docker image that includes the CNI and Device Plugin binaries.
   • Note: if testing on a multi-node cluster. The current absence of a Docker registry means this image will need to be manually copied to all nodes (or rebuilt on all nodes using: make image).
3. The damenonset will run on all nodes, installing the CNI and starting the Device Plugin running on each node.

The CNI and Device Plugin are now deployed.

Running Pods

• Create a network attachment definition file. This is the config for the CNI plugin.
  • An example file can be found under examples/network-attachment-definition.yaml
  • Change the config if necessary. See comments in the example file.
  • kubectl create -f network-attachment-definition.yaml
• Create a pod spec:
  • An example pod spec can be found under examples/pod-spec.yaml
  • Configure the pod spec to use a suitable Docker image and to reference the network attachment definition as well as the resource type from the Device Plugin. See comments in the example file.
  • kubectl create -f pod-spec.yaml

Device Plugin Config

Under normal circumstances the device plugin config is set as part of a config map at the top of the daemonset.yml file.

The device plugin binary can also be run manually on the host for development and testing purposes. In these scenarios the device plugin will search for a config.json file in its current directory, or the device plugin can be pointed to a config file using the -config flag followed by a filepath.

Driver Pools

It is possible to have multiple driver types in a single device pool. The example below will result in a pool named afxdp/intel that contains all the x710 and all E810 devices on the node.

{
    "pools" : [
        {
            "name" : "intel",
            "drivers" : ["i40e", "E810"]
        }
    ]
}

Device Pools

It is possible to assign individual devices to a pool. The example below will generate a pool named afxdp/test with the two listed devices. This is not scalable over many nodes and is intended only for development and testing purposes.

{
    "pools" : [
        {
            "name" : "test",
            "devices" : ["ens801f0", "ens801f1"],
        }
    ]
}

Logging

A log file and log level can be configured for the device plugin. As above, these are set in the config map at the top of the daemonset.yml file. Or, as above, a config.json file.

• The log file is set using logFile. This file should be placed under /var/log/afxdp-k8s-plugins/.
• The log level is set using logLevel. Available options are:
  • error - Only logs errors.
  • warning - Logs errors and warnings.
  • info - Logs errors, warnings and basic info about the operation of the device plugin.
  • debug - Logs all of the above along with additional in-depth info about the operation of the device plugin.
• Example config including log settings:

{
    "logLevel": "debug",
    "logFile": "/var/log/afxdp-k8s-plugins/afxdp-dp.log",
    "timeout": 30,
    "pools" : [
        {
            "name" : "i40e",
            "drivers" : ["i40e"]
        }
    ]
}

Mode

The device plugin allows for different modes of operation. CNDP is the only mode at present, with additional modes to be implemented in due course. Mode type must be configured for both device plugin and CNI.

Mode setting for device plugin is set via the config.json file. Please see example below:

{
    "mode": "cndp"
    "pools" : [
        {
            "name" : "i40e",
            "drivers" : ["i40e"]
        }
    ]
}

Mode setting for CNI is set via the network-attachment-definition(NAD) file NAD.yml. Please see mode example: examples/network-attachment-definition.yaml

Timeout

The device plugin includes a timeout action for the unix domain sockets(UDS). Once the timeout is invoked, the UDS is closed and disconnected.

The timeout can be set to a minimum of 30 seconds and a maximum of 300 seconds. If no timeout is configured, the plugin will default to the minimum 30.

The timeout value is set in the config.json file. Please see example below.

{
    "timeout": 30,
    "pools" : [
        {
            "name" : "i40e",
            "drivers" : ["i40e"]
        }
    ]
}

CLOC

Output from CLOC (count lines of code) - github.com/AlDanial/cloc

-------------------------------------------------------------------------------
Language                     files          blank        comment           code
-------------------------------------------------------------------------------
Go                              29            624           1070           4991
YAML                            11              8              0            546
Markdown                         3             72              0            430
Bourne Shell                     5             38             62            358
C                                2             34             29            151
make                             1             17             15            120
C/C++ Header                     2             10             28             28
JSON                             2              0              0             23
Dockerfile                       1              1             12              3
-------------------------------------------------------------------------------
SUM:                            56            804           1216           6650
-------------------------------------------------------------------------------

Sequence Diagram