cmd-forwarder-sriov

Intro

This repo contains 'cmd-forwarder-sriov' a SR-IOV based forwarder application for Network Service Mesh.

This README will provide directions for building, testing, and debugging that container.

Usage

SR-IOV forwarder binds one of the free VFs from the list of the configured PFs for each client request. It supports 2 mechanisms for the client:

• KERNEL_INTERFACE - binds VF to the kernel driver and passes kernel interface to the client net NS
• VFIO - binds VF to the vfio-pci driver and gives permissions to the client pod to work with the VF device

Also it works as a device plugin server providing resources for the client pods. Each configured PF adds VF count serviceDomain/capalility resources for every { serviceDomain, capability } pair.

Environment config

cmd-forwarder-sriov accept following environment variables:

• NSM_NAME - A string value of forwarder network service endpoint name (default sriov-forwarder)
• NSM_NS_NAME - A string value of forwarder network service name (default sriovns)
• NSM_CONNECT_TO - A Network Service Manager connectTo URL (default unix:///var/lib/networkservicemesh/nsm.io.sock)
• NSM_MAX_TOKEN_LIFETIME - A token lifetime duration (default 24h)
• NSM_RESOURCE_POLL_TIMEOUT - A timeout to poll device plugin resources usage from kubelet API (default 30s)
• NSM_DEVICE_PLUGIN_PATH - Path to the device plugin directory (default /var/lib/kubelet/device-plugins/)
• NSM_POD_RESOURCES_PATH - Path to the pod resources directory (default /var/lib/kubelet/pod-resources/)
• NSM_SRIOV_CONFIG_FILE - Path to the config file (default ./pci.config)
• NSM_PCI_DEVICES_PATH - Path to the PCI devices directory (default /sys/bus/pci/devices)
• NSM_PCI_DRIVERS_PATH - Path to the PCI drivers directory (default /sys/bus/pci/drivers)
• NSM_CGROUP_PATH - Path to the host /sys/fs/cgroup/devices directory (default /host/sys/fs/cgroup/devices)
• NSM_VFIO_PATH - Path to the host /dev/vfio directory (default /host/dev/vfio)

Config file

cmd-forwarder-sriov requires configuration file in the following format:

---
physicalFunctions:            # map [PCI address -> PF] for all supported PFs
  0000:01:00.0:
    pfKernelDriver: pf-driver # PF kernel driver
    vfKernelDriver: vf-driver # VFs kernel driver
    capabilities:             # list of the capabilities supported by the PF
      - intel
      - 10G
    serviceDomains:           # list of the service domains supported by the PF
      - service.domain.1

Build

Build cmd binary locally

You can build the locally by executing

go build ./...

Build Docker container

You can build the docker container by running:

docker build .

Testing

Testing Docker container

Testing is run via a Docker container. To run testing run:

docker run --privileged --rm $(docker build -q --target test .)

Debugging

Debugging the tests

If you wish to debug the test code itself, that can be acheived by running:

docker run --privileged --rm -p 40000:40000 $(docker build -q --target debug .)

This will result in the tests running under dlv. Connecting your debugger to localhost:40000 will allow you to debug.

-p 40000:40000

forwards port 40000 in the container to localhost:40000 where you can attach with your debugger.

--target debug

Runs the debug target, which is just like the test target, but starts tests with dlv listening on port 40000 inside the container.

Debugging the cmd

When you run 'cmd' you will see an early line of output that tells you:

Setting env variable DLV_LISTEN_FORWARDER to a valid dlv '--listen' value will cause the dlv debugger to execute this binary and listen as directed.

If you follow those instructions when running the Docker container:

docker run --privileged -e DLV_LISTEN_FORWARDER=:50000 -p 50000:50000 --rm $(docker build -q --target test .)

-e DLV_LISTEN_FORWARDER=:50000 tells docker to set the environment variable DLV_LISTEN_FORWARDER to :50000 telling dlv to listen on port 50000.

-p 50000:50000 tells docker to forward port 50000 in the container to port 50000 in the host. From there, you can just connect dlv using your favorite IDE and debug cmd.

Debugging the tests and the cmd

docker run --privileged -e DLV_LISTEN_FORWARDER=:50000 -p 40000:40000 -p 50000:50000 --rm $(docker build -q --target debug .)

Please note, the tests start the cmd, so until you connect to port 40000 with your debugger and walk the tests through to the point of running cmd, you will not be able to attach a debugger on port 50000 to the cmd.

A Note on Running golangci-lint

Because cmd-forwarder-sriov is only anticipated to run in Linux, you will need to run golangci-lint run with:

GOOS=linux golangci-lint run