gateway

Overview ¶

Package gateway provides an easily configurable server that can connect to multiple gNMI targets (devices) and relay received messages to various exporters and to downstream gNMI clients.

Targets are configured via a TargetLoader which generate all of the needed configuration for connecting to a target. See github.com/openconfig/gnmi/proto/target for details on the Configuration options that are available. See the TargetLoader docs for the minimum configuration required to connect to a target.

The gateway only supports TLS so you'll need to generate some keys first if you don't already have them. In production you should use properly signed TLS certificates.

# Generate private key (server.key)
openssl genrsa -out server.key 2048
# or
openssl ecparam -genkey -name secp384r1 -out server.key

# Generation of self-signed(x509) public key (server.crt) based on the private key (server.key)
openssl req -new -x509 -sha256 -key server.key -out server.crt -days 3650

You'll also need a copy of the latest OpenConfig YANG models if you don't already have it.

git clone https://github.com/openconfig/public.git oc-models

Finally, you need to build your target configurations. Copy targets-example.json to targets.json and edit it to match the targets you want to connect to.

cp targets-example.json targets.json
vim targets.json

See the example below or the Main() function in gateway.go for an example of how to start the server. If you'd like to just use the built-in loaders and exporters you can configure them more easily from the command line:

go build
./gnmi-gateway -EnableGNMIServer -EnablePrometheusExporter -OpenConfigDirectory=./oc-models/

config := &configuration.GatewayConfig{
	EnableGNMIServer:    true,
	OpenConfigDirectory: "./oc-models",
	ServerListenPort:    2906,
	ServerTLSCert:       "server.crt",
	ServerTLSKey:        "server.key",
	TargetLoaders: &configuration.TargetLoadersConfig{
		Enabled:                []string{"json"},
		JSONFile:               "targets.json",
		JSONFileReloadInterval: 60 * time.Second,
	},
	TargetDialTimeout: 5 * time.Second,
	TargetLimit:       100,
	ZookeeperHosts:    []string{"127.0.0.1"},
	ZookeeperTimeout:  1 * time.Second,
}

gateway := NewGateway(config)
err := gateway.StartGateway(&StartOpts{
	TargetLoaders: []loaders.TargetLoader{json.NewJSONFileTargetLoader(config)},
	Exporters: []exporters.Exporter{
		prometheus.NewPrometheusExporter(config),
	},
}) // run forever (or until an error happens)
if err != nil {
	fmt.Printf("Gateway exited with an error: %v", err)
	os.Exit(1)
}

Output: