removed --ethereum-chain-id flag (#201)

Removes the --ethereum-chain-id flag and updates the code to dynamically determines the chain ID using the ethereum endpoint.

protocol/backend/backend.go

@@ -61,7 +61,6 @@ type Backend interface {
 	// getters
 	Ctx() context.Context
 	Env() common.Environment
-	ChainID() *big.Int
 	CallOpts() *bind.CallOpts
 	TxOpts() (*bind.TransactOpts, error)
 	SwapManager() swap.Manager
@@ -103,7 +102,6 @@ type backend struct {
 	ethPrivKey *ecdsa.PrivateKey
 	callOpts   *bind.CallOpts
 	ethAddress ethcommon.Address
-	chainID    *big.Int
 	gasPrice   *big.Int
 	gasLimit   uint64
 
@@ -125,7 +123,6 @@ type Config struct {
 	EthereumClient     *ethclient.Client
 	EthereumPrivateKey *ecdsa.PrivateKey
 	Environment        common.Environment
-	ChainID            *big.Int
 	GasPrice           *big.Int
 	GasLimit           uint64
 
@@ -148,13 +145,16 @@ func NewBackend(cfg *Config) (Backend, error) {
 	var (
 		addr   ethcommon.Address
 		txOpts *txsender.TxOpts
-		err    error
 	)
 	if cfg.EthereumPrivateKey != nil {
 		addr = common.EthereumPrivateKeyToAddress(cfg.EthereumPrivateKey)
 
+		chainID, err := cfg.EthereumClient.ChainID(cfg.Ctx)
+		if err != nil {
+			return nil, err
+		}
 		// TODO: set gas limit + price based on network (#153)
-		txOpts, err = txsender.NewTxOpts(cfg.EthereumPrivateKey, cfg.ChainID)
+		txOpts, err = txsender.NewTxOpts(cfg.EthereumPrivateKey, chainID)
 		if err != nil {
 			return nil, err
 		}
@@ -175,7 +175,6 @@ func NewBackend(cfg *Config) (Backend, error) {
 			Context: cfg.Ctx,
 		},
 		ethAddress:      addr,
-		chainID:         cfg.ChainID,
 		gasPrice:        cfg.GasPrice,
 		gasLimit:        cfg.GasLimit,
 		txOpts:          txOpts,
@@ -205,10 +204,6 @@ func (b *backend) CallOpts() *bind.CallOpts {
 	return b.callOpts
 }
 
-func (b *backend) ChainID() *big.Int {
-	return b.chainID
-}
-
 func (b *backend) Contract() *contracts.SwapFactory {
 	return b.contract
 }
@@ -307,7 +302,11 @@ func (b *backend) TransactionReceipt(ctx context.Context, txHash ethcommon.Hash)
 }
 
 func (b *backend) TxOpts() (*bind.TransactOpts, error) {
-	txOpts, err := bind.NewKeyedTransactorWithChainID(b.ethPrivKey, b.chainID)
+	chainID, err := b.ethClient.ChainID(b.ctx)
+	if err != nil {
+		return nil, err
+	}
+	txOpts, err := bind.NewKeyedTransactorWithChainID(b.ethPrivKey, chainID)
 	if err != nil {
 		return nil, err
 	}

protocol/xmrmaker/mocks_test.go

@@ -79,20 +79,6 @@ func (mr *MockBackendMockRecorder) CallOpts() *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "CallOpts", reflect.TypeOf((*MockBackend)(nil).CallOpts))
 }
 
-// ChainID mocks base method.
-func (m *MockBackend) ChainID() *big.Int {
-	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "ChainID")
-	ret0, _ := ret[0].(*big.Int)
-	return ret0
-}
-
-// ChainID indicates an expected call of ChainID.
-func (mr *MockBackendMockRecorder) ChainID() *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ChainID", reflect.TypeOf((*MockBackend)(nil).ChainID))
-}
-
 // ClearXMRDepositAddress mocks base method.
 func (m *MockBackend) ClearXMRDepositAddress(arg0 types.Hash) {
 	m.ctrl.T.Helper()

protocol/xmrmaker/swap_state_test.go

@@ -73,7 +73,6 @@ func newTestXMRMaker(t *testing.T) *Instance {
 		EthereumClient:      ec,
 		EthereumPrivateKey:  pk,
 		Environment:         common.Development,
-		ChainID:             chainID,
 		SwapContract:        contract,
 		SwapContractAddress: addr,
 		SwapManager:         pswap.NewManager(),

protocol/xmrtaker/swap_state_test.go

@@ -68,7 +68,6 @@ func newBackend(t *testing.T) backend.Backend {
 		EthereumClient:      ec,
 		EthereumPrivateKey:  pk,
 		Environment:         common.Development,
-		ChainID:             chainID,
 		SwapManager:         pswap.NewManager(),
 		SwapContract:        contract,
 		SwapContractAddress: addr,
@@ -95,7 +94,6 @@ func newXMRMakerBackend(t *testing.T) backend.Backend {
 		EthereumClient:      ec,
 		EthereumPrivateKey:  pk,
 		Environment:         common.Development,
-		ChainID:             chainID,
 		SwapManager:         pswap.NewManager(),
 		SwapContract:        contract,
 		SwapContractAddress: addr,