Fix overflow in /metrics/validators and add denom exponent (solarlabs…

…team#18)

- Fix overflow when delegator tokens too large for /metrics/validators endpoint
- Add denom exponent to allow for easier custom denom definition
- Add documentation for denom exponent and coefficient to avoid confusion

README.md

@@ -132,6 +132,8 @@ You can pass the artuments to the executable file to configure it. Here is the p
 
 - `--bech-prefix` - the global prefix for addresses. Defaults to `persistence`
 - `--denom` - the currency, for example, `uatom` for Cosmos. Defaults to `uxprt`
+- `--denom-coefficient` - the number of decimals, `1000000` for cosmos. Defaults to `1`. Can't provide along with `--denom-exponent`
+- `--denom-exponent` - the denom exponent, `6` for cosmos. Defaults to `0`. Can't provide along with `--denom-coefficient`
 - `--listen-address` - the address with port the node would listen to. For example, you can use it to redefine port or to make the exporter accessible from the outside by listening on `127.0.0.1`. Defaults to `:9300` (so it's accessible from the outside on port 9300)
 - `--node` - the gRPC node URL. Defaults to `localhost:9090`
 - `--tendermint-rpc` - Tendermint RPC URL to query node stats (specifically `chain-id`). Defaults to `http://localhost:26657`

main.go

@@ -39,6 +39,7 @@ var (
 	ChainID          string
 	ConstLabels      map[string]string
 	DenomCoefficient float64
+	DenomExponent    uint64
 )
 
 var log = zerolog.New(zerolog.ConsoleWriter{Out: os.Stdout}).With().Timestamp().Logger()
@@ -135,6 +136,8 @@ func Execute(cmd *cobra.Command, args []string) {
 		Str("--bech-consensus-node-prefix", ConsensusNodePrefix).
 		Str("--bech-consensus-node-pubkey-prefix", ConsensusNodePubkeyPrefix).
 		Str("--denom", Denom).
+		Str("--denom-cofficient", fmt.Sprintf("%f", DenomCoefficient)).
+		Str("--denom-exponent", fmt.Sprintf("%d", DenomExponent)).
 		Str("--listen-address", ListenAddress).
 		Str("--node", NodeAddress).
 		Str("--log-level", LogLevel).
@@ -203,13 +206,9 @@ func setChainID() {
 }
 
 func setDenom(grpcConn *grpc.ClientConn) {
-	// if --denom and --denom-coefficient are both provided, use them
+	// if --denom and (--denom-coefficient or --denom-exponent) are provided, use them
 	// instead of fetching them via gRPC. Can be useful for networks like osmosis.
-	if Denom != "" && DenomCoefficient != 0 {
-		log.Info().
-			Str("denom", Denom).
-			Float64("coefficient", DenomCoefficient).
-			Msg("Using provided denom and coefficient.")
+	if isUserProvidedAndHandled := checkAndHandleDenomInfoProvidedByUser(); isUserProvidedAndHandled {
 		return
 	}
 
@@ -249,10 +248,43 @@ func setDenom(grpcConn *grpc.ClientConn) {
 	log.Fatal().Msg("Could not find the denom info")
 }
 
+func checkAndHandleDenomInfoProvidedByUser() bool {
+
+	if Denom != "" {
+		if DenomCoefficient != 1 && DenomExponent != 0 {
+			log.Fatal().Msg("denom-coefficient and denom-exponent are both provided. Must provide only one")
+		}
+
+		if DenomCoefficient != 1 {
+			log.Info().
+				Str("denom", Denom).
+				Float64("coefficient", DenomCoefficient).
+				Msg("Using provided denom and coefficient.")
+			return true
+		}
+
+		if DenomExponent != 0 {
+			DenomCoefficient = math.Pow10(int(DenomExponent))
+			log.Info().
+				Str("denom", Denom).
+				Uint64("exponent", DenomExponent).
+				Float64("calculated coefficient", DenomCoefficient).
+				Msg("Using provided denom and denom exponent and calculating coefficient.")
+			return true
+		}
+
+		return false
+	}
+
+	return false
+
+}
+
 func main() {
 	rootCmd.PersistentFlags().StringVar(&ConfigPath, "config", "", "Config file path")
 	rootCmd.PersistentFlags().StringVar(&Denom, "denom", "", "Cosmos coin denom")
-	rootCmd.PersistentFlags().Float64Var(&DenomCoefficient, "denom-coefficient", 0, "Denom coefficient")
+	rootCmd.PersistentFlags().Float64Var(&DenomCoefficient, "denom-coefficient", 1, "Denom coefficient")
+	rootCmd.PersistentFlags().Uint64Var(&DenomExponent, "denom-exponent", 0, "Denom exponent")
 	rootCmd.PersistentFlags().StringVar(&ListenAddress, "listen-address", ":9300", "The address this exporter would listen on")
 	rootCmd.PersistentFlags().StringVar(&NodeAddress, "node", "localhost:9090", "RPC node address")
 	rootCmd.PersistentFlags().StringVar(&LogLevel, "log-level", "info", "Logging level")

validators.go

@@ -249,11 +249,19 @@ func ValidatorsHandler(w http.ResponseWriter, r *http.Request, grpcConn *grpc.Cl
 			"moniker": validator.Description.Moniker,
 		}).Set(jailed)
 
-		validatorsTokensGauge.With(prometheus.Labels{
-			"address": validator.OperatorAddress,
-			"moniker": validator.Description.Moniker,
-			"denom":   Denom,
-		}).Set(float64(validator.Tokens.Int64()) / DenomCoefficient)
+		// because cosmos's dec doesn't have .toFloat64() method or whatever and returns everything as int
+		if value, err := strconv.ParseFloat(validator.Tokens.String(), 64); err != nil {
+			sublogger.Error().
+				Str("address", validator.OperatorAddress).
+				Err(err).
+				Msg("Could not parse delegator tokens")
+		} else {
+			validatorsTokensGauge.With(prometheus.Labels{
+				"address": validator.OperatorAddress,
+				"moniker": validator.Description.Moniker,
+				"denom":   Denom,
+			}).Set(value / DenomCoefficient) // a better way to do this is using math/big Div then checking IsInt64
+		}
 
 		// because cosmos's dec doesn't have .toFloat64() method or whatever and returns everything as int
 		if value, err := strconv.ParseFloat(validator.DelegatorShares.String(), 64); err != nil {
@@ -269,11 +277,19 @@ func ValidatorsHandler(w http.ResponseWriter, r *http.Request, grpcConn *grpc.Cl
 			}).Set(value / DenomCoefficient)
 		}
 
-		validatorsMinSelfDelegationGauge.With(prometheus.Labels{
-			"address": validator.OperatorAddress,
-			"moniker": validator.Description.Moniker,
-			"denom":   Denom,
-		}).Set(float64(validator.MinSelfDelegation.Int64()) / DenomCoefficient)
+		// because cosmos's dec doesn't have .toFloat64() method or whatever and returns everything as int
+		if value, err := strconv.ParseFloat(validator.MinSelfDelegation.String(), 64); err != nil {
+			sublogger.Error().
+				Str("address", validator.OperatorAddress).
+				Err(err).
+				Msg("Could not parse validator min self delegation")
+		} else {
+			validatorsMinSelfDelegationGauge.With(prometheus.Labels{
+				"address": validator.OperatorAddress,
+				"moniker": validator.Description.Moniker,
+				"denom":   Denom,
+			}).Set(value / DenomCoefficient)
+		}
 
 		err = validator.UnpackInterfaces(interfaceRegistry) // Unpack interfaces, to populate the Anys' cached values
 		if err != nil {