add extra validations to client creation in read-only mode (#1280)

Author: Tofel

seth/.changeset/v1.50.6.md

@@ -0,0 +1 @@
+- Adds `read-only` mode that can be useful if we are interested only in tracing and want to make sure that no write operations can be executed  

seth/README.md

@@ -813,11 +813,12 @@ With `SETH_LOG_LEVEL=trace` we will also log to console all traffic between Seth
 
 ### Read-only mode
 It's possible to use Seth in read-only mode only for transaction confirmation and tracing. Following operations will fail:
-* contract deployment
-* gas estimations (we need the pk/address to check nonce)
+* contract deployment (we need a pk to sign the transaction)
+* new transaction options (we need the pk/address to check nonce)
 * RPC health check (we need a pk to send a transaction to ourselves)
 * pending nonce protection (we need an address to check pending transactions)
 * ephemeral keys (we need a pk to fund them)
+* gas bumping (we need a pk to sign the transaction)
 
 The easiest way to enable read-only mode is to client via `ClientBuilder`:
 ```go
@@ -831,3 +832,10 @@ The easiest way to enable read-only mode is to client via `ClientBuilder`:
 ```
 
 when builder is called with `WithReadOnlyMode()` it will disable all the operations mentioned above and all the configuration settings related to them.
+
+Additionally, when the client is build anc `cfg.ReadOnly = true` is set, we will validate that:
+* no addresses and private keys are passed
+* no ephemeral addresses are to be created
+* RPC health check is disabled
+* pending nonce protection is disabled
+* gas bumping is disabled

seth/client.go

@@ -31,9 +31,15 @@ const (
 	ErrCreateNonceManager       = "failed to create nonce manager"
 	ErrCreateTracer             = "failed to create tracer"
 	ErrReadContractMap          = "failed to read deployed contract map"
-	ErrNoKeyLoaded              = "failed to load private key"
 	ErrRpcHealthCheckFailed     = "RPC health check failed ¯\\_(ツ)_/¯"
 	ErrContractDeploymentFailed = "contract deployment failed"
+	ErrNoPksEphemeralMode       = "no private keys loaded, cannot fund ephemeral addresses"
+
+	ErrReadOnlyWithPrivateKeys = "read-only mode is enabled, but you tried to load private keys"
+	ErrReadOnlyEphemeralKeys   = "ephemeral mode is not supported in read-only mode"
+	ErrReadOnlyGasBumping      = "gas bumping is not supported in read-only mode"
+	ErrReadOnlyRpcHealth       = "RPC health check is not supported in read-only mode"
+	ErrReadOnlyPendingNonce    = "pending nonce protection is not supported in read-only mode"
 
 	ContractMapFilePattern          = "deployed_contracts_%s_%s.toml"
 	RevertedTransactionsFilePattern = "reverted_transactions_%s_%s.json"
@@ -231,6 +237,11 @@ func NewClientRaw(
 	if len(cfg.Network.URLs) > 1 {
 		L.Warn().Msg("Multiple RPC URLs provided, only the first one will be used")
 	}
+
+	if cfg.ReadOnly && (len(addrs) > 0 || len(pkeys) > 0) {
+		return nil, errors.New(ErrReadOnlyWithPrivateKeys)
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), cfg.Network.DialTimeout.Duration())
 	defer cancel()
 	rpcClient, err := rpc.DialOptions(ctx,
@@ -303,6 +314,9 @@ func NewClientRaw(
 	}
 
 	if cfg.CheckRpcHealthOnStart {
+		if cfg.ReadOnly {
+			return nil, errors.New(ErrReadOnlyRpcHealth)
+		}
 		if c.NonceManager == nil {
 			L.Debug().Msg("Nonce manager is not set, RPC health check will be skipped. Client will most probably fail on first transaction")
 		} else {
@@ -312,6 +326,10 @@ func NewClientRaw(
 		}
 	}
 
+	if cfg.PendingNonceProtectionEnabled && cfg.ReadOnly {
+		return nil, errors.New(ErrReadOnlyPendingNonce)
+	}
+
 	cfg.setEphemeralAddrs()
 
 	L.Info().
@@ -324,7 +342,10 @@ func NewClientRaw(
 
 	if cfg.ephemeral {
 		if len(c.Addresses) == 0 {
-			return nil, errors.New("no private keys loaded, cannot fund ephemeral addresses")
+			return nil, errors.New(ErrNoPksEphemeralMode)
+		}
+		if cfg.ReadOnly {
+			return nil, errors.New(ErrReadOnlyEphemeralKeys)
 		}
 		gasPrice, err := c.GetSuggestedLegacyFees(context.Background(), Priority_Standard)
 		if err != nil {
@@ -392,6 +413,10 @@ func NewClientRaw(
 		}
 	}
 
+	if c.Cfg.GasBump != nil && c.Cfg.GasBump.Retries != 0 && c.Cfg.ReadOnly {
+		return nil, errors.New(ErrReadOnlyGasBumping)
+	}
+
 	// if gas bumping is enabled, but no strategy is set, we set the default one; otherwise we set the no-op strategy (defensive programming to avoid NPE)
 	if c.Cfg.GasBump != nil && c.Cfg.GasBump.StrategyFn == nil {
 		if c.Cfg.GasBumpRetries() != 0 {

seth/client_builder.go

@@ -393,6 +393,7 @@ func (c *ClientBuilder) handleReadOnlyMode() {
 		c.config.PendingNonceProtectionEnabled = false
 		c.config.CheckRpcHealthOnStart = false
 		c.config.EphemeralAddrs = nil
+		c.readonly = true
 		if c.config.Network != nil {
 			c.config.Network.GasPriceEstimationEnabled = false
 			c.config.Network.PrivateKeys = []string{}

seth/config.go

@@ -67,6 +67,7 @@ type Config struct {
 	CheckRpcHealthOnStart         bool              `toml:"check_rpc_health_on_start"`
 	BlockStatsConfig              *BlockStatsConfig `toml:"block_stats"`
 	GasBump                       *GasBumpConfig    `toml:"gas_bump"`
+	ReadOnly                      bool              `toml:"read_only"`
 }
 
 type GasBumpConfig struct {

seth/config_test.go

@@ -465,3 +465,98 @@ func TestConfigAppendPkToInactiveNetwork(t *testing.T) {
 	require.Equal(t, 0, len(cfg.Networks[0].PrivateKeys), "network should have 0 pks")
 	require.Equal(t, []string{"pk"}, cfg.Networks[1].PrivateKeys, "network should have 1 pk")
 }
+
+func TestConfig_ReadOnly_WithPk(t *testing.T) {
+	cfg := seth.Config{
+		ReadOnly: true,
+		Network: &seth.Network{
+			Name: "some_other",
+			URLs: []string{"ws://localhost:8546"},
+		},
+	}
+
+	addrs := []common.Address{common.HexToAddress("0xb794f5ea0ba39494ce839613fffba74279579268")}
+
+	_, err := seth.NewClientRaw(&cfg, addrs, nil)
+	require.Error(t, err, "succeeded in creating client")
+	require.Equal(t, seth.ErrReadOnlyWithPrivateKeys, err.Error(), "expected different error message")
+
+	privateKey, err := crypto.HexToECDSA("ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80")
+	require.NoError(t, err, "failed to parse private key")
+
+	pks := []*ecdsa.PrivateKey{privateKey}
+	_, err = seth.NewClientRaw(&cfg, nil, pks)
+	require.Error(t, err, "succeeded in creating client")
+	require.Equal(t, seth.ErrReadOnlyWithPrivateKeys, err.Error(), "expected different error message")
+
+	_, err = seth.NewClientRaw(&cfg, addrs, pks)
+	require.Error(t, err, "succeeded in creating client")
+	require.Equal(t, seth.ErrReadOnlyWithPrivateKeys, err.Error(), "expected different error message")
+}
+
+func TestConfig_ReadOnly_GasBumping(t *testing.T) {
+	cfg := seth.Config{
+		ReadOnly: true,
+		Network: &seth.Network{
+			Name:        "some_other",
+			URLs:        []string{"ws://localhost:8546"},
+			DialTimeout: &seth.Duration{D: 10 * time.Second},
+		},
+		GasBump: &seth.GasBumpConfig{
+			Retries: uint(1),
+		},
+	}
+
+	_, err := seth.NewClientRaw(&cfg, nil, nil)
+	require.Error(t, err, "succeeded in creating client")
+	require.Equal(t, seth.ErrReadOnlyGasBumping, err.Error(), "expected different error message")
+}
+
+func TestConfig_ReadOnly_RpcHealth(t *testing.T) {
+	cfg := seth.Config{
+		ReadOnly:              true,
+		CheckRpcHealthOnStart: true,
+		Network: &seth.Network{
+			Name:        "some_other",
+			URLs:        []string{"ws://localhost:8546"},
+			DialTimeout: &seth.Duration{D: 10 * time.Second},
+		},
+	}
+
+	_, err := seth.NewClientRaw(&cfg, nil, nil)
+	require.Error(t, err, "succeeded in creating client")
+	require.Equal(t, seth.ErrReadOnlyRpcHealth, err.Error(), "expected different error message")
+}
+
+func TestConfig_ReadOnly_PendingNonce(t *testing.T) {
+	cfg := seth.Config{
+		ReadOnly:                      true,
+		PendingNonceProtectionEnabled: true,
+		Network: &seth.Network{
+			Name:        "some_other",
+			URLs:        []string{"ws://localhost:8546"},
+			DialTimeout: &seth.Duration{D: 10 * time.Second},
+		},
+	}
+
+	_, err := seth.NewClientRaw(&cfg, nil, nil)
+	require.Error(t, err, "succeeded in creating client")
+	require.Equal(t, seth.ErrReadOnlyPendingNonce, err.Error(), "expected different error message")
+}
+
+func TestConfig_ReadOnly_EphemeralKeys(t *testing.T) {
+	ten := int64(10)
+	cfg := seth.Config{
+		ReadOnly:       true,
+		EphemeralAddrs: &ten,
+		Network: &seth.Network{
+			Name:        "some_other",
+			URLs:        []string{"ws://localhost:8546"},
+			DialTimeout: &seth.Duration{D: 10 * time.Second},
+		},
+	}
+
+	_, err := seth.NewClientRaw(&cfg, nil, nil)
+	require.Error(t, err, "succeeded in creating client")
+	require.Equal(t, seth.ErrNoPksEphemeralMode, err.Error(), "expected different error message")
+}

seth/seth.toml

@@ -55,6 +55,11 @@ experiments_enabled = ["slow_funds_return", "eip_1559_fee_equalizer"]
 # to make sure transaction can be submitted and mined
 check_rpc_health_on_start = false
 
+# when enabled, upon creation Seth will validate that there are no private keys set, that node RPC health check is disabled
+# and that gas bumping is disabled, since all of these operations are "write" operations. This is useful for running Seth
+# only for tracing, when you want to make sure that no transactions are sent to the network.
+read_only = false
+
 [gas_bumps]
 # when > 0 then we will bump gas price for transactions that are stuck in the mempool
 # by default the bump step is controlled by gas_price_estimation_tx_priority (check readme.md for more details)