config: parse different ZMQ hosts for block and tx notifications

Due to recent changes to the BitcoindClient interface, we now require
the backing bitcoind to use different hosts for its ZMQ raw block and
raw transaction notifications. This was needed as the notification queue
maintained by the bitcoind node would sometimes overflow with
transactions and cause block notifications to be dropped/missed.
In this commit, we expand extractBitcoindRPCParams to account for this.

config.go

@@ -133,11 +133,12 @@ type btcdConfig struct {
 }
 
 type bitcoindConfig struct {
-	Dir     string `long:"dir" description:"The base directory that contains the node's data, logs, configuration file, etc."`
+	Dir            string `long:"dir" description:"The base directory that contains the node's data, logs, configuration file, etc."`
-	RPCHost string `long:"rpchost" description:"The daemon's rpc listening address. If a port is omitted, then the default port for the selected chain parameters will be used."`
+	RPCHost        string `long:"rpchost" description:"The daemon's rpc listening address. If a port is omitted, then the default port for the selected chain parameters will be used."`
-	RPCUser string `long:"rpcuser" description:"Username for RPC connections"`
+	RPCUser        string `long:"rpcuser" description:"Username for RPC connections"`
-	RPCPass string `long:"rpcpass" default-mask:"-" description:"Password for RPC connections"`
+	RPCPass        string `long:"rpcpass" default-mask:"-" description:"Password for RPC connections"`
-	ZMQPath string `long:"zmqpath" description:"The path to the ZMQ socket providing at least raw blocks. Raw transactions can be handled as well."`
+	ZMQPubRawBlock string `long:"zmqpubrawblock" description:"The address listening for ZMQ connections to deliver raw block notifications"`
+	ZMQPubRawTx    string `long:"zmqpubrawtx" description:"The address listening for ZMQ connections to deliver raw transaction notifications"`
 }
 
 type autoPilotConfig struct {
@@ -1057,8 +1058,12 @@ func parseRPCParams(cConfig *chainConfig, nodeConfig interface{}, net chainCode,
 		switch net {
 		case bitcoinChain:
 			daemonName = "btcd"
+			confDir = conf.Dir
+			confFile = "btcd"
 		case litecoinChain:
 			daemonName = "ltcd"
+			confDir = conf.Dir
+			confFile = "ltcd"
 		}
 
 		// If only ONE of RPCUser or RPCPass is set, we assume the
@@ -1068,18 +1073,11 @@ func parseRPCParams(cConfig *chainConfig, nodeConfig interface{}, net chainCode,
 				"%[1]v.rpcuser, %[1]v.rpcpass", daemonName)
 		}
 
-		switch net {
-		case bitcoinChain:
-			confDir = conf.Dir
-			confFile = "btcd"
-		case litecoinChain:
-			confDir = conf.Dir
-			confFile = "ltcd"
-		}
 	case *bitcoindConfig:
-		// If all of RPCUser, RPCPass, and ZMQPath are set, we assume
+		// If all of RPCUser, RPCPass, ZMQBlockHost, and ZMQTxHost are
-		// those parameters are good to use.
+		// set, we assume those parameters are good to use.
-		if conf.RPCUser != "" && conf.RPCPass != "" && conf.ZMQPath != "" {
+		if conf.RPCUser != "" && conf.RPCPass != "" &&
+			conf.ZMQPubRawBlock != "" && conf.ZMQPubRawTx != "" {
 			return nil
 		}
 
@@ -1087,25 +1085,24 @@ func parseRPCParams(cConfig *chainConfig, nodeConfig interface{}, net chainCode,
 		switch net {
 		case bitcoinChain:
 			daemonName = "bitcoind"
-		case litecoinChain:
-			daemonName = "litecoind"
-		}
-		// If only one or two of the parameters are set, we assume the
-		// user did that unintentionally.
-		if conf.RPCUser != "" || conf.RPCPass != "" || conf.ZMQPath != "" {
-			return fmt.Errorf("please set all or none of "+
-				"%[1]v.rpcuser, %[1]v.rpcpass, "+
-				"and %[1]v.zmqpath", daemonName)
-		}
-
-		switch net {
-		case bitcoinChain:
 			confDir = conf.Dir
 			confFile = "bitcoin"
 		case litecoinChain:
+			daemonName = "litecoind"
 			confDir = conf.Dir
 			confFile = "litecoin"
 		}
+
+		// If only one or two of the parameters are set, we assume the
+		// user did that unintentionally.
+		if conf.RPCUser != "" || conf.RPCPass != "" ||
+			conf.ZMQPubRawBlock != "" || conf.ZMQPubRawTx != "" {
+
+			return fmt.Errorf("please set all or none of "+
+				"%[1]v.rpcuser, %[1]v.rpcpass, "+
+				"%[1]v.zmqpubrawblock, %[1]v.zmqpubrawtx",
+				daemonName)
+		}
 	}
 
 	// If we're in simnet mode, then the running btcd instance won't read
@@ -1132,13 +1129,15 @@ func parseRPCParams(cConfig *chainConfig, nodeConfig interface{}, net chainCode,
 		nConf.RPCUser, nConf.RPCPass = rpcUser, rpcPass
 	case "bitcoind", "litecoind":
 		nConf := nodeConfig.(*bitcoindConfig)
-		rpcUser, rpcPass, zmqPath, err := extractBitcoindRPCParams(confFile)
+		rpcUser, rpcPass, zmqBlockHost, zmqTxHost, err :=
+			extractBitcoindRPCParams(confFile)
 		if err != nil {
 			return fmt.Errorf("unable to extract RPC credentials:"+
 				" %v, cannot start w/o RPC connection",
 				err)
 		}
-		nConf.RPCUser, nConf.RPCPass, nConf.ZMQPath = rpcUser, rpcPass, zmqPath
+		nConf.RPCUser, nConf.RPCPass = rpcUser, rpcPass
+		nConf.ZMQPubRawBlock, nConf.ZMQPubRawTx = zmqBlockHost, zmqTxHost
 	}
 
 	fmt.Printf("Automatically obtained %v's RPC credentials\n", daemonName)
@@ -1196,13 +1195,12 @@ func extractBtcdRPCParams(btcdConfigPath string) (string, string, error) {
 // location of bitcoind's bitcoin.conf on the target system. The routine looks
 // for a cookie first, optionally following the datadir configuration option in
 // the bitcoin.conf. If it doesn't find one, it looks for rpcuser/rpcpassword.
-func extractBitcoindRPCParams(bitcoindConfigPath string) (string, string, string, error) {
+func extractBitcoindRPCParams(bitcoindConfigPath string) (string, string, string, string, error) {
-
 	// First, we'll open up the bitcoind configuration file found at the
 	// target destination.
 	bitcoindConfigFile, err := os.Open(bitcoindConfigPath)
 	if err != nil {
-		return "", "", "", err
+		return "", "", "", "", err
 	}
 	defer bitcoindConfigFile.Close()
 
@@ -1210,18 +1208,36 @@ func extractBitcoindRPCParams(bitcoindConfigPath string) (string, string, string
 	// we can attempt to locate the RPC credentials.
 	configContents, err := ioutil.ReadAll(bitcoindConfigFile)
 	if err != nil {
-		return "", "", "", err
+		return "", "", "", "", err
 	}
 
-	// First, we look for the ZMQ path for raw blocks. If raw transactions
+	// First, we'll look for the ZMQ hosts providing raw block and raw
-	// are sent over this interface, we can also get unconfirmed txs.
+	// transaction notifications.
-	zmqPathRE, err := regexp.Compile(`(?m)^\s*zmqpubrawblock\s*=\s*([^\s]+)`)
+	zmqBlockHostRE, err := regexp.Compile(
+		`(?m)^\s*zmqpubrawblock\s*=\s*([^\s]+)`,
+	)
 	if err != nil {
-		return "", "", "", err
+		return "", "", "", "", err
 	}
-	zmqPathSubmatches := zmqPathRE.FindSubmatch(configContents)
+	zmqBlockHostSubmatches := zmqBlockHostRE.FindSubmatch(configContents)
-	if len(zmqPathSubmatches) < 2 {
+	if len(zmqBlockHostSubmatches) < 2 {
-		return "", "", "", fmt.Errorf("unable to find zmqpubrawblock in config")
+		return "", "", "", "", fmt.Errorf("unable to find " +
+			"zmqpubrawblock in config")
+	}
+	zmqTxHostRE, err := regexp.Compile(`(?m)^\s*zmqpubrawtx\s*=\s*([^\s]+)`)
+	if err != nil {
+		return "", "", "", "", err
+	}
+	zmqTxHostSubmatches := zmqTxHostRE.FindSubmatch(configContents)
+	if len(zmqTxHostSubmatches) < 2 {
+		return "", "", "", "", errors.New("unable to find zmqpubrawtx " +
+			"in config")
+	}
+	zmqBlockHost := string(zmqBlockHostSubmatches[1])
+	zmqTxHost := string(zmqTxHostSubmatches[1])
+	if zmqBlockHost == zmqTxHost {
+		return "", "", "", "", errors.New("zmqpubrawblock and " +
+			"zmqpubrawtx must be different")
 	}
 
 	// Next, we'll try to find an auth cookie. We need to detect the chain
@@ -1229,7 +1245,7 @@ func extractBitcoindRPCParams(bitcoindConfigPath string) (string, string, string
 	dataDir := path.Dir(bitcoindConfigPath)
 	dataDirRE, err := regexp.Compile(`(?m)^\s*datadir\s*=\s*([^\s]+)`)
 	if err != nil {
-		return "", "", "", err
+		return "", "", "", "", err
 	}
 	dataDirSubmatches := dataDirRE.FindSubmatch(configContents)
 	if dataDirSubmatches != nil {
@@ -1250,8 +1266,8 @@ func extractBitcoindRPCParams(bitcoindConfigPath string) (string, string, string
 	if err == nil {
 		splitCookie := strings.Split(string(cookie), ":")
 		if len(splitCookie) == 2 {
-			return splitCookie[0], splitCookie[1],
+			return splitCookie[0], splitCookie[1], zmqBlockHost,
-				string(zmqPathSubmatches[1]), nil
+				zmqTxHost, nil
 		}
 	}
 
@@ -1260,11 +1276,12 @@ func extractBitcoindRPCParams(bitcoindConfigPath string) (string, string, string
 	// expression then we'll exit with an error.
 	rpcUserRegexp, err := regexp.Compile(`(?m)^\s*rpcuser\s*=\s*([^\s]+)`)
 	if err != nil {
-		return "", "", "", err
+		return "", "", "", "", err
 	}
 	userSubmatches := rpcUserRegexp.FindSubmatch(configContents)
 	if userSubmatches == nil {
-		return "", "", "", fmt.Errorf("unable to find rpcuser in config")
+		return "", "", "", "", fmt.Errorf("unable to find rpcuser in " +
+			"config")
 	}
 
 	// Similarly, we'll use another regular expression to find the set
@@ -1272,15 +1289,16 @@ func extractBitcoindRPCParams(bitcoindConfigPath string) (string, string, string
 	// error.
 	rpcPassRegexp, err := regexp.Compile(`(?m)^\s*rpcpassword\s*=\s*([^\s]+)`)
 	if err != nil {
-		return "", "", "", err
+		return "", "", "", "", err
 	}
 	passSubmatches := rpcPassRegexp.FindSubmatch(configContents)
 	if passSubmatches == nil {
-		return "", "", "", fmt.Errorf("unable to find rpcpassword in config")
+		return "", "", "", "", fmt.Errorf("unable to find rpcpassword " +
+			"in config")
 	}
 
 	return string(userSubmatches[1]), string(passSubmatches[1]),
-		string(zmqPathSubmatches[1]), nil
+		zmqBlockHost, zmqTxHost, nil
 }
 
 // normalizeNetwork returns the common name of a network type used to create