common/flags: Fix parsing of metrics.labels, if provided in config .yml

.changelog/2905.bugfix.md

@@ -0,0 +1 @@
+common/flags: Fix parsing of metrics.labels, if provided in config .yml

go/oasis-node/cmd/common/flags/flags.go

@@ -94,15 +94,19 @@ func DryRun() bool {
 
 // GetStringMapString is a drop-in replacement for viper.GetStringMapString due to https://github.com/spf13/viper/issues/608.
 func GetStringMapString(key string) map[string]string {
-	labels := map[string]string{}
-	val := viper.GetString(key)
-
-	// viper.GetString() wraps the string inside [] parenthesis, unwrap it.
-	if len(val) < 2 {
+	// Use original GetStringMapString, if it works (e.g. for yaml-based configs).
+	labels := viper.GetStringMapString(key)
+	if len(labels) != 0 {
 		return labels
 	}
-	val = val[1 : len(val)-1]
 
+	// Otherwise, take string and parse it manually.
+	val := viper.GetString(key)
+	// viper.GetString() wraps the string inside [] parenthesis, unwrap it.
+	if len(val) >= 2 && val[0] == '[' && val[len(val)-1] == ']' {
+		val = val[1 : len(val)-1]
+	}
+	// Assume format key1=value1,key2=value2,...
 	for _, lPair := range strings.Split(val, ",") {
 		kv := strings.Split(lPair, "=")
 		if len(kv) != 2 || kv[0] == "" {