fix: proper error when parsing telemetry configuration (backport cosm…

…os#12981) (cosmos#12998)

* fix: proper error when parsing telemetry configuration (cosmos#12981)

When parsing `telemetry.global-labels` config the code assumes that the type will be an array.  I saw an issue where someone edited the configuration in the wrong way and got the following error:
![photo_2022-08-21_08-02-21](https://user-images.githubusercontent.com/22855163/185793842-c5759a54-1860-4dd1-bdb4-b94f4dab3c16.jpg)
Instead, I suggest here to print a proper error log to indicate what the issue is.

(cherry picked from commit c24c439)

* add changelog

Co-authored-by: liorbond <liorbond@gmail.com>
Co-authored-by: Julien Robert <julien@rbrt.fr>

CHANGELOG.md

@@ -40,6 +40,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* [#12981](https://github.com/cosmos/cosmos-sdk/pull/12981) Return proper error when parsing telemetry configuration.
 * [#12969](https://github.com/cosmos/cosmos-sdk/pull/12969) Bump Tendermint to `v0.34.21` and IAVL to `v0.19.1`.
 * [#12886](https://github.com/cosmos/cosmos-sdk/pull/12886) Amortize cost of processing cache KV store.
 * (events) [#12850](https://github.com/cosmos/cosmos-sdk/pull/12850) Add a new `fee_payer` attribute to the `tx` event that is emitted from the `DeductFeeDecorator` AnteHandler decorator.

server/config/config.go

@@ -267,11 +267,82 @@ func DefaultConfig() *Config {
 
 // GetConfig returns a fully parsed Config object.
 func GetConfig(v *viper.Viper) (Config, error) {
-	conf := DefaultConfig()
-	if err := v.Unmarshal(conf); err != nil {
-		return Config{}, fmt.Errorf("error extracting app config: %w", err)
+	globalLabelsRaw, ok := v.Get("telemetry.global-labels").([]interface{})
+	if !ok {
+		return Config{}, fmt.Errorf("failed to parse global-labels config")
 	}
-	return *conf, nil
+
+	globalLabels := make([][]string, 0, len(globalLabelsRaw))
+	for idx, glr := range globalLabelsRaw {
+		labelsRaw, ok := glr.([]interface{})
+		if !ok {
+			return Config{}, fmt.Errorf("failed to parse global label number %d from config", idx)
+		}
+		if len(labelsRaw) == 2 {
+			globalLabels = append(globalLabels, []string{labelsRaw[0].(string), labelsRaw[1].(string)})
+		}
+	}
+
+	return Config{
+		BaseConfig: BaseConfig{
+			MinGasPrices:      v.GetString("minimum-gas-prices"),
+			InterBlockCache:   v.GetBool("inter-block-cache"),
+			Pruning:           v.GetString("pruning"),
+			PruningKeepRecent: v.GetString("pruning-keep-recent"),
+			PruningInterval:   v.GetString("pruning-interval"),
+			HaltHeight:        v.GetUint64("halt-height"),
+			HaltTime:          v.GetUint64("halt-time"),
+			IndexEvents:       v.GetStringSlice("index-events"),
+			MinRetainBlocks:   v.GetUint64("min-retain-blocks"),
+			IAVLCacheSize:     v.GetUint64("iavl-cache-size"),
+			AppDBBackend:      v.GetString("app-db-backend"),
+		},
+		Telemetry: telemetry.Config{
+			ServiceName:             v.GetString("telemetry.service-name"),
+			Enabled:                 v.GetBool("telemetry.enabled"),
+			EnableHostname:          v.GetBool("telemetry.enable-hostname"),
+			EnableHostnameLabel:     v.GetBool("telemetry.enable-hostname-label"),
+			EnableServiceLabel:      v.GetBool("telemetry.enable-service-label"),
+			PrometheusRetentionTime: v.GetInt64("telemetry.prometheus-retention-time"),
+			GlobalLabels:            globalLabels,
+		},
+		API: APIConfig{
+			Enable:             v.GetBool("api.enable"),
+			Swagger:            v.GetBool("api.swagger"),
+			Address:            v.GetString("api.address"),
+			MaxOpenConnections: v.GetUint("api.max-open-connections"),
+			RPCReadTimeout:     v.GetUint("api.rpc-read-timeout"),
+			RPCWriteTimeout:    v.GetUint("api.rpc-write-timeout"),
+			RPCMaxBodyBytes:    v.GetUint("api.rpc-max-body-bytes"),
+			EnableUnsafeCORS:   v.GetBool("api.enabled-unsafe-cors"),
+		},
+		Rosetta: RosettaConfig{
+			Enable:              v.GetBool("rosetta.enable"),
+			Address:             v.GetString("rosetta.address"),
+			Blockchain:          v.GetString("rosetta.blockchain"),
+			Network:             v.GetString("rosetta.network"),
+			Retries:             v.GetInt("rosetta.retries"),
+			Offline:             v.GetBool("rosetta.offline"),
+			EnableFeeSuggestion: v.GetBool("rosetta.enable-fee-suggestion"),
+			GasToSuggest:        v.GetInt("rosetta.gas-to-suggest"),
+			DenomToSuggest:      v.GetString("rosetta.denom-to-suggest"),
+		},
+		GRPC: GRPCConfig{
+			Enable:         v.GetBool("grpc.enable"),
+			Address:        v.GetString("grpc.address"),
+			MaxRecvMsgSize: v.GetInt("grpc.max-recv-msg-size"),
+			MaxSendMsgSize: v.GetInt("grpc.max-send-msg-size"),
+		},
+		GRPCWeb: GRPCWebConfig{
+			Enable:           v.GetBool("grpc-web.enable"),
+			Address:          v.GetString("grpc-web.address"),
+			EnableUnsafeCORS: v.GetBool("grpc-web.enable-unsafe-cors"),
+		},
+		StateSync: StateSyncConfig{
+			SnapshotInterval:   v.GetUint64("state-sync.snapshot-interval"),
+			SnapshotKeepRecent: v.GetUint32("state-sync.snapshot-keep-recent"),
+		},
+	}, nil
 }
 
 // ValidateBasic returns an error if min-gas-prices field is empty in BaseConfig. Otherwise, it returns nil.

server/start.go

@@ -217,7 +217,13 @@ func start[T types.Application](svrCtx *Context, clientCtx client.Context, appCr
 	}
 
 	app := appCreator(ctx.Logger, db, traceWriter, ctx.Viper)
-	_, err = startTelemetry(serverconfig.GetConfig(ctx.Viper))
+
+	config, err := serverconfig.GetConfig(ctx.Viper)
+	if err != nil {
+		return err
+	}
+
+	_, err = startTelemetry(config)
 	if err != nil {
 		return err
 	}
@@ -338,11 +344,15 @@ func startInProcess[T types.Application](svrCtx *Context, svrCfg serverconfig.Co
 		return err
 	}
 
-	config, err := config.GetConfig(ctx.Viper)
+	config, err := serverconfig.GetConfig(ctx.Viper)
 	if err != nil {
 		return err
 	}
 
+	if err := config.ValidateBasic(); err != nil {
+		return err
+	}
+
 	if err := config.ValidateBasic(); err != nil {
 		ctx.Logger.Error("WARNING: The minimum-gas-prices config in app.toml is set to the empty string. " +
 			"This defaults to 0 in the current version, but will error in the next version " +