all: add ability to set arbitrary tags on resource struct

cmd/geth/main.go

@@ -201,6 +201,7 @@ var (
 		utils.RPCTelemetryUserFlag,
 		utils.RPCTelemetryPasswordFlag,
 		utils.RPCTelemetryInstanceIDFlag,
+		utils.RPCTelemetryTagsFlag,
 		utils.RPCTelemetrySampleRatioFlag,
 	}
 

cmd/utils/flags.go

@@ -1074,6 +1074,12 @@ Please note that --` + MetricsHTTPFlag.Name + ` must be set to start the server.
 		Category: flags.APICategory,
 	}
 
+	RPCTelemetryTagsFlag = &cli.StringFlag{
+		Name:     "rpc.telemetry.tags",
+		Usage:    "Comma-separated tags (key/values) added as attributes to the OpenTelemetry resource struct",
+		Category: flags.APICategory,
+	}
+
 	RPCTelemetrySampleRatioFlag = &cli.Float64Flag{
 		Name:     "rpc.telemetry.sample-ratio",
 		Usage:    "Defines the sampling ratio for RPC telemetry (0.0 to 1.0)",
@@ -1543,7 +1549,6 @@ func setOpenTelemetry(ctx *cli.Context, cfg *node.Config) {
 	if ctx.IsSet(RPCTelemetryFlag.Name) {
 		tcfg.Enabled = ctx.Bool(RPCTelemetryFlag.Name)
 	}
-
 	if ctx.IsSet(RPCTelemetryEndpointFlag.Name) {
 		tcfg.Endpoint = ctx.String(RPCTelemetryEndpointFlag.Name)
 	}
@@ -1553,10 +1558,13 @@ func setOpenTelemetry(ctx *cli.Context, cfg *node.Config) {
 	if ctx.IsSet(RPCTelemetryPasswordFlag.Name) {
 		tcfg.AuthPassword = ctx.String(RPCTelemetryPasswordFlag.Name)
 	}
-	tcfg.SampleRatio = ctx.Float64(RPCTelemetrySampleRatioFlag.Name)
 	if ctx.IsSet(RPCTelemetryInstanceIDFlag.Name) {
 		tcfg.InstanceID = ctx.String(RPCTelemetryInstanceIDFlag.Name)
 	}
+	if ctx.IsSet(RPCTelemetryTagsFlag.Name) {
+		tcfg.Tags = ctx.String(RPCTelemetryTagsFlag.Name)
+	}
+	tcfg.SampleRatio = ctx.Float64(RPCTelemetrySampleRatioFlag.Name)
 
 	if tcfg.Endpoint != "" && !tcfg.Enabled {
 		log.Warn(fmt.Sprintf("OpenTelemetry endpoint configured but telemetry is not enabled, use --%s to enable.", RPCTelemetryFlag.Name))

internal/telemetry/tracesetup/setup.go

@@ -21,6 +21,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"net/url"
+	"strings"
 	"time"
 
 	"github.com/ethereum/go-ethereum/internal/version"
@@ -121,14 +122,24 @@ func SetupTelemetry(cfg node.OpenTelemetryConfig, stack *node.Node) error {
 		sdktrace.WithBatchTimeout(time.Duration(sdktrace.DefaultScheduleDelay) * time.Millisecond),
 	}
 
-	// Define resource with service and client information
+	// Define resource attributes
 	var attr = []attribute.KeyValue{
 		semconv.ServiceName("geth"),
 		attribute.String("client.name", version.ClientName("geth")),
 	}
+	// Add instance ID if provided
 	if cfg.InstanceID != "" {
 		attr = append(attr, semconv.ServiceInstanceID(cfg.InstanceID))
 	}
+	// Add custom tags if provided
+	if cfg.Tags != "" {
+		for tag := range strings.SplitSeq(cfg.Tags, ",") {
+			key, value, ok := strings.Cut(tag, "=")
+			if ok {
+				attr = append(attr, attribute.String(key, value))
+			}
+		}
+	}
 	res := resource.NewWithAttributes(semconv.SchemaURL, attr...)
 
 	// Configure TracerProvider and set it as the global tracer provider

node/config.go

@@ -221,6 +221,7 @@ type Config struct {
 type OpenTelemetryConfig struct {
 	Enabled bool `toml:",omitempty"`
 
+	Tags       string `toml:",omitempty"`
 	InstanceID string `toml:",omitempty"`
 
 	// Exporter endpoint.