Add an option to expose Prometheus metrics via http/s server

Signed-off-by: Botond Szirtes <[email protected]>

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/networkservicemesh/sdk v0.5.1-0.20240820090035-6fad31a9f0aa
 	github.com/networkservicemesh/sdk-kernel v0.0.0-20240820090342-573b7f288d21
 	github.com/pkg/errors v0.9.1
+	github.com/prometheus/client_golang v1.17.0
 	github.com/stretchr/testify v1.8.4
 	github.com/vishvananda/netlink v1.2.1-beta.2.0.20220630165224-c591ada0fb2b
 	github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74
@@ -52,7 +53,6 @@ require (
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/open-policy-agent/opa v0.44.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/prometheus/client_golang v1.17.0 // indirect
 	github.com/prometheus/client_model v0.5.0 // indirect
 	github.com/prometheus/common v0.44.0 // indirect
 	github.com/prometheus/procfs v0.11.1 // indirect

pkg/networkservice/metrics/stats/common.go

@@ -32,6 +32,7 @@ import (
 
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
 	"github.com/networkservicemesh/sdk/pkg/tools/log"
+	"github.com/networkservicemesh/sdk/pkg/tools/prometheus"
 	"github.com/pkg/errors"
 
 	"github.com/networkservicemesh/sdk-vpp/pkg/tools/ifindex"
@@ -67,6 +68,23 @@ func retrieveMetrics(ctx context.Context, statsConn *core.StatsConnection, segme
 		segment.Metrics[addName+"rx_packets"] = strconv.FormatUint(iface.Rx.Packets, 10)
 		segment.Metrics[addName+"tx_packets"] = strconv.FormatUint(iface.Tx.Packets, 10)
 		segment.Metrics[addName+"drops"] = strconv.FormatUint(iface.Drops, 10)
+
+		if prometheus.IsEnabled() {
+			if addName == "server_" {
+				ServerRxBytes.Set(float64(iface.Rx.Bytes))
+				ServerTxBytes.Set(float64(iface.Tx.Bytes))
+				ServerRxPackets.Set(float64(iface.Rx.Packets))
+				ServerTxPackets.Set(float64(iface.Tx.Packets))
+				ServerDrops.Set(float64(iface.Drops))
+			} else {
+				ClientRxBytes.Set(float64(iface.Rx.Bytes))
+				ClientTxBytes.Set(float64(iface.Tx.Bytes))
+				ClientRxPackets.Set(float64(iface.Rx.Packets))
+				ClientTxPackets.Set(float64(iface.Tx.Packets))
+				ClientDrops.Set(float64(iface.Drops))
+			}
+		}
+
 		break
 	}
 }

pkg/networkservice/metrics/stats/prometheus.go

@@ -0,0 +1,87 @@
+package stats
+
+import (
+	prom "github.com/networkservicemesh/sdk/pkg/tools/prometheus"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	ClientRxBytes = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "client_rx_bytes_total",
+			Help: "Total received bytes by client",
+		},
+	)
+	ClientTxBytes = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "client_tx_bytes_total",
+			Help: "Total transmitted bytes by client",
+		},
+	)
+	ClientRxPackets = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "client_rx_packets_total",
+			Help: "Total received packets by client",
+		},
+	)
+	ClientTxPackets = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "client_tx_packets_total",
+			Help: "Total transmitted packets by client",
+		},
+	)
+	ClientDrops = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "client_drops_total",
+			Help: "Total drops by client",
+		},
+	)
+	ServerRxBytes = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "server_rx_bytes_total",
+			Help: "Total received bytes by server",
+		},
+	)
+	ServerTxBytes = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "server_tx_bytes_total",
+			Help: "Total transmitted bytes by server",
+		},
+	)
+
+	ServerRxPackets = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "server_rx_packets_total",
+			Help: "Total received packets by server",
+		},
+	)
+
+	ServerTxPackets = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "server_tx_packets_total",
+			Help: "Total transmitted packets by server",
+		},
+	)
+
+	ServerDrops = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "server_drops_total",
+			Help: "Total drops by server",
+		},
+	)
+)
+
+func init() {
+	if prom.IsEnabled() {
+		prometheus.MustRegister(ClientRxBytes)
+		prometheus.MustRegister(ClientTxBytes)
+		prometheus.MustRegister(ClientRxPackets)
+		prometheus.MustRegister(ClientTxPackets)
+		prometheus.MustRegister(ClientDrops)
+		prometheus.MustRegister(ServerRxBytes)
+		prometheus.MustRegister(ServerTxBytes)
+		prometheus.MustRegister(ServerRxPackets)
+		prometheus.MustRegister(ServerTxPackets)
+		prometheus.MustRegister(ServerDrops)
+	}
+}