lemming

Lemming the Openconfig reference device implementation

Purpose

To provide a reference implementation of a device which provides the collection of customers APIs used for Openconfig. This includes:

• gNMI
• gNOI
• gRIBI
• P4RT
• BGP
• ISIS

to clearly and authoritatively specify the expected behavior of an OpenConfig-compliant device, and to aid in its test development and debugging. Anyone can use this reference implementation to quickly write device tests independent of the availability of a real and compliant implementation. The reference can also be used to augment the consumer contract when a fake-derived test suite is delivered to network device vendors, serving as a tool for consensus in the device-implementor <-> device-consumer relationship.

Running the Fake gNMI Server

go run ./cmd/lemming --zapi_addr unix:/tmp/zserv.api --alsologtostderr

Wait for the message "lemming initialization complete".
This might take a minute the first time to compile the large generated code.

Install gnmic: https://gnmic.openconfig.net/

// SetRequest configuring hostname
gnmic -a localhost:9339 --insecure -u foo -p bar --target fakedut set --update-path openconfig:/system/config/hostname --update-value rosesarered -e json_ietf

// SubscribeRequest/ONCE getting configured hostname
gnmic -a localhost:9339 --insecure -u foo -p bar --target fakedut subscribe --mode once --path openconfig:/system/config/hostname

// SubscribeRequest/ONCE getting hostname reflected as system state
gnmic -a localhost:9339 --insecure -u foo -p bar --target fakedut subscribe --mode once --path openconfig:/system/state/hostname

Running integration tests

Prerequisites:

• KNE setup and cluster deployed

Deploy and Test:

• Optional: Build and load lemming container from source: make load
• Run integration tests: go test ./integration_tests/...

Debugging Lemming

1. Load the debug image in the cluster: make load-debug
2. Modify a topology.pb.txt to start lemming with dlv.

nodes: {
    name: "lemming"
    vendor: OPENCONFIG
    config: {
        command: "/dlv/dlv"
        args: "exec"
        args: "--headless"
        args: "--continue"
        args: "--accept-multiclient"
        args: "--listen=:56268"
        args: "--api-version=2"
        args: "/lemming/lemming"
        args: "--"
    }
}

1. Create the topology: kne create <topofile>.
2. Forward the debugger connection (this is blocking so run in seperate terminal): kubectl port-forward -n <topo name> <node name> 56268:56268
3. Attach to the debugger.
   1. Using VS Code: Run and Debug -> Connect to server
   2. Using dlv cli: dlv connect localhost:56268
      1. Required: Configure subsitute-path so dlv can resolve source code: config substitute-path /build <abs path to lemming src>