keep BitcoinConfig to be backward compatible

changelog.md

@@ -19,6 +19,7 @@
 * [2784](https://github.com/zeta-chain/node/pull/2784) - staking precompiled contract
 * [2795](https://github.com/zeta-chain/node/pull/2795) - support restricted address in Solana
 * [2861](https://github.com/zeta-chain/node/pull/2861) - emit events from staking precompile
+* [2870](https://github.com/zeta-chain/node/pull/2870) - support for multiple Bitcoin chains in the zetaclient
 
 ### Refactor
 

cmd/zetaclientd/start_utils.go

@@ -75,6 +75,9 @@ func maskCfg(cfg config.Config) string {
 			RPCParams: val.RPCParams,
 		}
 	}
+	maskedCfg.BitcoinConfig = config.BTCConfig{
+		RPCParams: cfg.BitcoinConfig.RPCParams,
+	}
 
 	// Mask Solana endpoint
 	maskedCfg.SolanaConfig.Endpoint = ""

zetaclient/config/config_chain.go

@@ -31,7 +31,7 @@ func New(setDefaults bool) Config {
 // bitcoinConfigRegnet contains Bitcoin config for regnet
 func bitcoinConfigRegnet() BTCConfig {
 	return BTCConfig{
-		RPCUsername: "smoketest", // smoketest is the previous name for E2E test, we keep this name for compatibility between client versions in upgrade test
+		RPCUsername: "e2etest",
 		RPCPassword: "123",
 		RPCHost:     "bitcoin:18443",
 		RPCParams:   "regtest",

zetaclient/config/types.go

@@ -89,7 +89,9 @@ type Config struct {
 	// chain configs
 	EVMChainConfigs map[int64]EVMConfig `json:"EVMChainConfigs"`
 	BTCChainConfigs map[int64]BTCConfig `json:"BTCChainConfigs"`
-	SolanaConfig    SolanaConfig        `json:"SolanaConfig"`
+	// Deprecated: the 'BitcoinConfig' will be removed once the 'BTCChainConfigs' is fully adopted
+	BitcoinConfig BTCConfig    `json:"BitcoinConfig"`
+	SolanaConfig  SolanaConfig `json:"SolanaConfig"`
 
 	// compliance config
 	ComplianceConfig ComplianceConfig `json:"ComplianceConfig"`
@@ -124,7 +126,13 @@ func (c Config) GetBTCConfig(chainID int64) (BTCConfig, bool) {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
-	btcCfg := c.BTCChainConfigs[chainID]
+	// we prefer 'BTCChainConfigs' over 'BitcoinConfig' but still fallback to be backward compatible
+	// this will allow new 'zetaclientd' binary to work with old config file
+	btcCfg, found := c.BTCChainConfigs[chainID]
+	if !found || btcCfg.Empty() {
+		btcCfg = c.BitcoinConfig
+	}
+
 	return btcCfg, !btcCfg.Empty()
 }
 

zetaclient/config/types_test.go

@@ -63,29 +63,42 @@ func Test_GetEVMConfig(t *testing.T) {
 
 func Test_GetBTCConfig(t *testing.T) {
 	tests := []struct {
-		name     string
-		chainID  int64
-		chainCfg config.BTCConfig
-		want     bool
+		name    string
+		chainID int64
+		oldCfg  config.BTCConfig
+		btcCfg  *config.BTCConfig
+		want    bool
 	}{
 		{
 			name:    "should find non-empty btc config",
 			chainID: chains.BitcoinRegtest.ChainId,
-			chainCfg: config.BTCConfig{
-				RPCUsername: "",
-				RPCPassword: "",
-				RPCHost:     "localhost",
-				RPCParams:   "",
+			btcCfg: &config.BTCConfig{
+				RPCHost: "localhost",
 			},
 			want: true,
 		},
 		{
-			name:    "should not find btc config if rpc host is empty",
+			name:    "should fallback to old 'BitcoinConfig' if new config is not set",
 			chainID: chains.BitcoinRegtest.ChainId,
-			chainCfg: config.BTCConfig{
+			oldCfg: config.BTCConfig{
+				RPCHost: "old_host",
+			},
+			btcCfg: nil, // new config is not set
+			want:   true,
+		},
+		{
+			name:    "should fallback to old config but still can't find btc config as it's empty",
+			chainID: chains.BitcoinRegtest.ChainId,
+			oldCfg: config.BTCConfig{
+				RPCUsername: "user",
+				RPCPassword: "pass",
+				RPCHost:     "", // empty config
+				RPCParams:   "regtest",
+			},
+			btcCfg: &config.BTCConfig{
 				RPCUsername: "user",
 				RPCPassword: "pass",
-				RPCHost:     "",
+				RPCHost:     "", // empty config
 				RPCParams:   "regtest",
 			},
 			want: false,
@@ -97,8 +110,11 @@ func Test_GetBTCConfig(t *testing.T) {
 			// create config with defaults
 			cfg := config.New(true)
 
-			// set chain config
-			cfg.BTCChainConfigs[tt.chainID] = tt.chainCfg
+			// set both new and old btc config
+			cfg.BitcoinConfig = tt.oldCfg
+			if tt.btcCfg != nil {
+				cfg.BTCChainConfigs[tt.chainID] = *tt.btcCfg
+			}
 
 			// should return btc config
 			btcCfg, found := cfg.GetBTCConfig(tt.chainID)