lib/promrelabel: fix parsing regex: true in relabeling rules

docs/CHANGELOG.md

@@ -7,6 +7,7 @@ sort: 15
 ## tip
 
 * BUGFIX: vmselect: fix accessing [Graphite APIs](https://docs.victoriametrics.com/#graphite-api-usage). The access has been broken in v1.66.0, because `/graphite/*` path prefix accidentally clashed with `/graph*` path prefix used for VictoriaMetrics UI (aka `vmui`).
+* BUGFIX: fix parsing `regex: <bool_or_number>` in relabeling rules (for example, `regex: true` or `regex: 123`). The bug has been introduced in v1.66.0.
 
 
 ## [v1.66.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.66.0)

lib/promrelabel/config.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"regexp"
+	"strconv"
 	"strings"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/envtemplate"
@@ -45,29 +46,51 @@ func (mlr *MultiLineRegex) UnmarshalYAML(f func(interface{}) error) error {
 	if err := f(&v); err != nil {
 		return err
 	}
-	var a []string
+	s, err := stringValue(v)
+	if err != nil {
+		return err
+	}
+	mlr.s = s
+	return nil
+}
+
+func stringValue(v interface{}) (string, error) {
+	if v == nil {
+		return "null", nil
+	}
 	switch x := v.(type) {
-	case string:
-		a = []string{x}
 	case []interface{}:
-		a = make([]string, len(x))
+		a := make([]string, len(x))
 		for i, xx := range x {
-			s, ok := xx.(string)
-			if !ok {
-				return fmt.Errorf("`regex` must contain array of strings; got %T", xx)
+			s, err := stringValue(xx)
+			if err != nil {
+				return "", err
 			}
 			a[i] = s
 		}
-	default:
-		return fmt.Errorf("unexpected type for `regex`: %T; want string or []string", v)
+		return strings.Join(a, "|"), nil
+	case string:
+		return x, nil
+	case float64:
+		return strconv.FormatFloat(x, 'f', -1, 64), nil
+	case int:
+		return strconv.Itoa(x), nil
+	case bool:
+		if x {
+			return "true", nil
+		}
+		return "false", nil
+	default:
+		return "", fmt.Errorf("unexpected type for `regex`: %T; want string or []string", v)
 	}
-	mlr.s = strings.Join(a, "|")
-	return nil
 }
 
 // MarshalYAML marshals mlr to YAML.
 func (mlr *MultiLineRegex) MarshalYAML() (interface{}, error) {
 	a := strings.Split(mlr.s, "|")
+	if len(a) == 1 {
+		return a[0], nil
+	}
 	return a, nil
 }
 

lib/promrelabel/config_test.go

@@ -26,13 +26,25 @@ func TestRelabelConfigMarshalUnmarshal(t *testing.T) {
 	f(`
 - action: keep
   regex: foobar
-`, "- regex:\n  - foobar\n  action: keep\n")
+`, "- regex: foobar\n  action: keep\n")
 	f(`
 - regex:
   - 'fo.+'
   - '.*ba[r-z]a'
 `, "- regex:\n  - fo.+\n  - .*ba[r-z]a\n")
 	f(`- regex: foo|bar`, "- regex:\n  - foo\n  - bar\n")
+	f(`- regex: True`, `- regex: "true"`+"\n")
+	f(`- regex: true`, `- regex: "true"`+"\n")
+	f(`- regex: 123`, `- regex: "123"`+"\n")
+	f(`- regex: 1.23`, `- regex: "1.23"`+"\n")
+	f(`- regex: [null]`, `- regex: "null"`+"\n")
+	f(`
+- regex:
+  - -1.23
+  - False
+  - null
+  - nan
+`, "- regex:\n  - \"-1.23\"\n  - \"false\"\n  - \"null\"\n  - nan\n")
 }
 
 func TestLoadRelabelConfigsSuccess(t *testing.T) {