chore: inject W3C headers into engine client and eth client (#2958)

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## Overview

Part of #2956

Injects W3C headers into engine client and eth client, this will allow
us to set up proper traces (with some changes to ev-reth to respect
them)

I will add additional spans in a follow up.

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Author: chatton

apps/evm/cmd/run.go

@@ -13,6 +13,7 @@ import (
 	"github.com/rs/zerolog"
 	"github.com/spf13/cobra"
 
+	"github.com/evstack/ev-node/apps/evm/server"
 	"github.com/evstack/ev-node/block"
 	"github.com/evstack/ev-node/core/execution"
 	coresequencer "github.com/evstack/ev-node/core/sequencer"
@@ -29,8 +30,6 @@ import (
 	"github.com/evstack/ev-node/pkg/sequencers/based"
 	"github.com/evstack/ev-node/pkg/sequencers/single"
 	"github.com/evstack/ev-node/pkg/store"
-
-	"github.com/evstack/ev-node/apps/evm/server"
 )
 
 const (
@@ -56,7 +55,8 @@ var RunCmd = &cobra.Command{
 			return err
 		}
 
-		executor, err := createExecutionClient(cmd, datastore)
+		tracingEnabled := nodeConfig.Instrumentation.IsTracingEnabled()
+		executor, err := createExecutionClient(cmd, datastore, tracingEnabled)
 		if err != nil {
 			return err
 		}
@@ -201,7 +201,7 @@ func createSequencer(
 	return sequencer, nil
 }
 
-func createExecutionClient(cmd *cobra.Command, db datastore.Batching) (execution.Executor, error) {
+func createExecutionClient(cmd *cobra.Command, db datastore.Batching, tracingEnabled bool) (execution.Executor, error) {
 	// Read execution client parameters from flags
 	ethURL, err := cmd.Flags().GetString(evm.FlagEvmEthURL)
 	if err != nil {
@@ -246,7 +246,7 @@ func createExecutionClient(cmd *cobra.Command, db datastore.Batching) (execution
 	genesisHash := common.HexToHash(genesisHashStr)
 	feeRecipient := common.HexToAddress(feeRecipientStr)
 
-	return evm.NewEngineExecutionClient(ethURL, engineURL, jwtSecret, genesisHash, feeRecipient, db)
+	return evm.NewEngineExecutionClient(ethURL, engineURL, jwtSecret, genesisHash, feeRecipient, db, tracingEnabled)
 }
 
 // addFlags adds flags related to the EVM execution client

execution/evm/execution.go

@@ -23,6 +23,7 @@ import (
 	"github.com/rs/zerolog"
 
 	"github.com/evstack/ev-node/core/execution"
+	"github.com/evstack/ev-node/pkg/telemetry"
 )
 
 const (
@@ -157,40 +158,55 @@ type EngineClient struct {
 // The db parameter is required for ExecMeta tracking which enables idempotent
 // execution and crash recovery. The db is wrapped with a prefix to isolate
 // EVM execution data from other ev-node data.
+// When tracingEnabled is true, the client will inject W3C trace context headers
+// and wrap Engine API calls with OpenTelemetry spans.
 func NewEngineExecutionClient(
 	ethURL,
 	engineURL string,
 	jwtSecret string,
 	genesisHash common.Hash,
 	feeRecipient common.Address,
 	db ds.Batching,
+	tracingEnabled bool,
 ) (*EngineClient, error) {
 	if db == nil {
 		return nil, errors.New("db is required for EVM execution client")
 	}
 
-	ethClient, err := ethclient.Dial(ethURL)
+	var rpcOpts []rpc.ClientOption
+	// If tracing enabled, add W3C header propagation to rpcOpts
+	if tracingEnabled {
+		rpcOpts = append(rpcOpts, rpc.WithHTTPClient(
+			telemetry.NewPropagatingHTTPClient(http.DefaultTransport)))
+	}
+
+	// Create ETH RPC client with HTTP options
+	ethRPC, err := rpc.DialOptions(context.Background(), ethURL, rpcOpts...)
 	if err != nil {
 		return nil, err
 	}
+	ethClient := ethclient.NewClient(ethRPC)
 
 	secret, err := decodeSecret(jwtSecret)
 	if err != nil {
 		return nil, err
 	}
 
-	engineClient, err := rpc.DialOptions(context.Background(), engineURL,
-		rpc.WithHTTPAuth(func(h http.Header) error {
-			authToken, err := getAuthToken(secret)
-			if err != nil {
-				return err
-			}
-
-			if authToken != "" {
-				h.Set("Authorization", "Bearer "+authToken)
-			}
-			return nil
-		}))
+	// Create Engine RPC with optional HTTP client and JWT auth
+	// Compose engine options: pass-through rpcOpts plus JWT auth
+	engineOptions := make([]rpc.ClientOption, len(rpcOpts))
+	copy(engineOptions, rpcOpts) // copy to avoid using same backing array from rpcOpts.
+	engineOptions = append(engineOptions, rpc.WithHTTPAuth(func(h http.Header) error {
+		authToken, err := getAuthToken(secret)
+		if err != nil {
+			return err
+		}
+		if authToken != "" {
+			h.Set("Authorization", "Bearer "+authToken)
+		}
+		return nil
+	}))
+	engineClient, err := rpc.DialOptions(context.Background(), engineURL, engineOptions...)
 	if err != nil {
 		return nil, err
 	}

execution/evm/go.mod

@@ -4,6 +4,7 @@ go 1.24.6
 
 require (
 	github.com/ethereum/go-ethereum v1.16.7
+	github.com/evstack/ev-node v1.0.0-beta.10
 	github.com/evstack/ev-node/core v1.0.0-beta.5
 	github.com/golang-jwt/jwt/v5 v5.3.0
 	github.com/ipfs/go-datastore v0.9.0
@@ -18,8 +19,10 @@ require (
 	github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251001021608-1fe7b43fc4d6 // indirect
 	github.com/StackExchange/wmi v1.2.1 // indirect
 	github.com/bits-and-blooms/bitset v1.20.0 // indirect
+	github.com/celestiaorg/go-square/v3 v3.0.2 // indirect
+	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/consensys/gnark-crypto v0.18.0 // indirect
-	github.com/cpuguy83/go-md2man/v2 v2.0.6 // indirect
 	github.com/crate-crypto/go-eth-kzg v1.4.0 // indirect
 	github.com/crate-crypto/go-ipa v0.0.0-20240724233137-53bbb0ceb27a // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
@@ -29,33 +32,76 @@ require (
 	github.com/ethereum/c-kzg-4844/v2 v2.1.5 // indirect
 	github.com/ethereum/go-verkle v0.2.2 // indirect
 	github.com/ferranbt/fastssz v0.1.4 // indirect
+	github.com/fsnotify/fsnotify v1.9.0 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-ole/go-ole v1.3.0 // indirect
+	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
+	github.com/goccy/go-yaml v1.19.0 // indirect
 	github.com/gofrs/flock v0.12.1 // indirect
 	github.com/golang/snappy v1.0.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/gorilla/websocket v1.5.3 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.2 // indirect
 	github.com/holiman/uint256 v1.3.2 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/ipfs/go-cid v0.6.0 // indirect
 	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/minio/sha256-simd v1.0.1 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/mr-tron/base58 v1.2.0 // indirect
+	github.com/multiformats/go-base32 v0.1.0 // indirect
+	github.com/multiformats/go-base36 v0.2.0 // indirect
+	github.com/multiformats/go-multiaddr v0.16.1 // indirect
+	github.com/multiformats/go-multibase v0.2.0 // indirect
+	github.com/multiformats/go-multihash v0.2.3 // indirect
+	github.com/multiformats/go-varint v0.1.0 // indirect
 	github.com/olekukonko/tablewriter v0.0.5 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
-	github.com/rogpeppe/go-internal v1.14.1 // indirect
 	github.com/rs/cors v1.11.1 // indirect
+	github.com/sagikazarmark/locafero v0.11.0 // indirect
 	github.com/shirou/gopsutil v3.21.4-0.20210419000835-c7a38de76ee5+incompatible // indirect
+	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
+	github.com/spaolacci/murmur3 v1.1.0 // indirect
+	github.com/spf13/afero v1.15.0 // indirect
+	github.com/spf13/cast v1.10.0 // indirect
+	github.com/spf13/cobra v1.10.2 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/spf13/viper v1.21.0 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/supranational/blst v0.3.16-0.20250831170142-f48500c1fdbe // indirect
 	github.com/syndtr/goleveldb v1.0.1-0.20220721030215-126854af5e6d // indirect
 	github.com/tklauser/go-sysconf v0.3.12 // indirect
 	github.com/tklauser/numcpus v0.6.1 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/otel v1.39.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.38.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.38.0 // indirect
+	go.opentelemetry.io/otel/metric v1.39.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.38.0 // indirect
+	go.opentelemetry.io/otel/trace v1.39.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.7.1 // indirect
+	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/crypto v0.46.0 // indirect
+	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
+	golang.org/x/net v0.48.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
+	golang.org/x/text v0.32.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20250825161204-c5933d9347a5 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250825161204-c5933d9347a5 // indirect
+	google.golang.org/grpc v1.75.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	lukechampine.com/blake3 v1.4.1 // indirect
 )
 
-replace github.com/evstack/ev-node/core => ../../core
+replace (
+	github.com/evstack/ev-node => ../../
+	github.com/evstack/ev-node/core => ../../core
+)