provide MatchCase option to match case of keys or not

server/datasource/etcd/kv/kv_dao.go

@@ -485,7 +485,10 @@ func toRegex(opts datasource.FindOptions) (*regexp.Regexp, error) {
 	default:
 		value = strings.ReplaceAll(opts.Key, ".", "\\.")
 	}
-	value = "(?i)^" + value + "$"
+	value += "$"
+	if opts.MatchCase == false {
+		value = "(?i)^" + value
+	}
 	regex, err := regexp.Compile(value)
 	if err != nil {
 		openlog.Error("invalid wildcard expr: " + value + ", error: " + err.Error())

server/datasource/options.go

@@ -70,7 +70,8 @@ type FindOptions struct {
 	// Offset the offset of the response, start at 0
 	Offset int64
 	// Limit the page size of the response, dot not paging if limit=0
-	Limit int64
+	Limit     int64
+	MatchCase bool
 }
 
 // WriteOption is functional option to create, update and delete kv
@@ -86,6 +87,13 @@ func WithSync(enabled bool) WriteOption {
 	}
 }
 
+// WithMatchCase tell model service whether to match case of letters or not.
+func WithMatchCase() FindOption {
+	return func(o *FindOptions) {
+		o.MatchCase = true
+	}
+}
+
 // WithExactLabels tell model service to return only one kv matches the labels
 func WithExactLabels() FindOption {
 	return func(o *FindOptions) {