eth, cmd: remove syncTarget from eth config (ethereum#26330)

--syncTarget is a feature for development purpose in post-merge world. Previously
it's added into eth.Config. But it turns out that's a stupid idea.

- syncTarget is a block object, which is hard to be put in config file(large)
- syncTarget is just a dev feature, doesn't make too much sense to add it in config file

So I remove it from the eth config object. And it also fixes the ethereum#26328

cmd/geth/config.go

@@ -31,6 +31,7 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/scwallet"
 	"github.com/ethereum/go-ethereum/accounts/usbwallet"
 	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/ethconfig"
 	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/internal/flags"
@@ -165,7 +166,7 @@ func makeFullNode(ctx *cli.Context) (*node.Node, ethapi.Backend) {
 		cfg.Eth.OverrideTerminalTotalDifficultyPassed = &override
 	}
 
-	backend, _ := utils.RegisterEthService(stack, &cfg.Eth)
+	backend, eth := utils.RegisterEthService(stack, &cfg.Eth)
 
 	// Configure log filter RPC API.
 	filterSystem := utils.RegisterFilterAPI(stack, backend, &cfg.Eth)
@@ -179,6 +180,11 @@ func makeFullNode(ctx *cli.Context) (*node.Node, ethapi.Backend) {
 	if cfg.Ethstats.URL != "" {
 		utils.RegisterEthStatsService(stack, backend, cfg.Ethstats.URL)
 	}
+
+	// Configure full-sync tester service if requested
+	if ctx.IsSet(utils.SyncTargetFlag.Name) && cfg.Eth.SyncMode == downloader.FullSync {
+		utils.RegisterFullSyncTester(stack, eth, ctx.Path(utils.SyncTargetFlag.Name))
+	}
 	return stack, backend
 }
 

cmd/utils/flags.go

@@ -1880,25 +1880,6 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 			cfg.EthDiscoveryURLs = SplitAndTrim(urls)
 		}
 	}
-	if ctx.IsSet(SyncTargetFlag.Name) {
-		path := ctx.Path(SyncTargetFlag.Name)
-		if path == "" {
-			Fatalf("Failed to resolve file path")
-		}
-		blob, err := os.ReadFile(path)
-		if err != nil {
-			Fatalf("Failed to read block file: %v", err)
-		}
-		rlpBlob, err := hexutil.Decode(string(bytes.TrimRight(blob, "\r\n")))
-		if err != nil {
-			Fatalf("Failed to decode block blob: %v", err)
-		}
-		var block types.Block
-		if err := rlp.DecodeBytes(rlpBlob, &block); err != nil {
-			Fatalf("Failed to decode block: %v", err)
-		}
-		cfg.SyncTarget = &block
-	}
 	// Override any default configs for hard coded networks.
 	switch {
 	case ctx.Bool(MainnetFlag.Name):
@@ -2052,13 +2033,6 @@ func RegisterEthService(stack *node.Node, cfg *ethconfig.Config) (ethapi.Backend
 		Fatalf("Failed to register the Engine API service: %v", err)
 	}
 	stack.RegisterAPIs(tracers.APIs(backend.APIBackend))
-
-	// Register the auxiliary full-sync tester service in case the sync
-	// target is configured.
-	if cfg.SyncTarget != nil && cfg.SyncMode == downloader.FullSync {
-		ethcatalyst.RegisterFullSyncTester(stack, backend, cfg.SyncTarget)
-		log.Info("Registered full-sync tester", "number", cfg.SyncTarget.NumberU64(), "hash", cfg.SyncTarget.Hash())
-	}
 	return backend.APIBackend, backend
 }
 
@@ -2090,6 +2064,24 @@ func RegisterFilterAPI(stack *node.Node, backend ethapi.Backend, ethcfg *ethconf
 	return filterSystem
 }
 
+// RegisterFullSyncTester adds the full-sync tester service into node.
+func RegisterFullSyncTester(stack *node.Node, eth *eth.Ethereum, path string) {
+	blob, err := os.ReadFile(path)
+	if err != nil {
+		Fatalf("Failed to read block file: %v", err)
+	}
+	rlpBlob, err := hexutil.Decode(string(bytes.TrimRight(blob, "\r\n")))
+	if err != nil {
+		Fatalf("Failed to decode block blob: %v", err)
+	}
+	var block types.Block
+	if err := rlp.DecodeBytes(rlpBlob, &block); err != nil {
+		Fatalf("Failed to decode block: %v", err)
+	}
+	ethcatalyst.RegisterFullSyncTester(stack, eth, &block)
+	log.Info("Registered full-sync tester", "number", block.NumberU64(), "hash", block.Hash())
+}
+
 func SetupMetrics(ctx *cli.Context) {
 	if metrics.Enabled {
 		log.Info("Enabling metrics collection")

eth/ethconfig/config.go

@@ -32,7 +32,6 @@ import (
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/txpool"
-	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 	"github.com/ethereum/go-ethereum/ethdb"
@@ -212,10 +211,6 @@ type Config struct {
 
 	// OverrideTerminalTotalDifficultyPassed (TODO: remove after the fork)
 	OverrideTerminalTotalDifficultyPassed *bool `toml:",omitempty"`
-
-	// SyncTarget defines the target block of sync. It's only used for
-	// development purposes.
-	SyncTarget *types.Block
 }
 
 // CreateConsensusEngine creates a consensus engine for the given chain configuration.