feat(filter): Add error handling for regex compilation

moira-alert · Oct 10, 2023 · befb374 · befb374
1 parent 015eb55
commit befb374
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Showing 2 changed files with 32 additions and 16 deletions.
diff --git a/filter/series_by_tag.go b/filter/series_by_tag.go
@@ -129,15 +129,19 @@ func ParseSeriesByTag(input string) ([]TagSpec, error) {
 type MatchingHandler func(string, map[string]string) bool
 
 // CreateMatchingHandlerForPattern creates function for matching by tag list
-func CreateMatchingHandlerForPattern(tagSpecs []TagSpec, compatibility *Compatibility) (string, MatchingHandler) {
+func CreateMatchingHandlerForPattern(tagSpecs []TagSpec, compatibility *Compatibility) (string, MatchingHandler, error) {
 	matchingHandlers := make([]MatchingHandler, 0)
 	var nameTagValue string
 
 	for _, tagSpec := range tagSpecs {
 		if tagSpec.Name == "name" && tagSpec.Operator == EqualOperator {
 			nameTagValue = tagSpec.Value
 		} else {
-			handler := createMatchingHandlerForOneTag(tagSpec, compatibility)
+			handler, err := createMatchingHandlerForOneTag(tagSpec, compatibility)
+			if err != nil {
+				return "", nil, err
+			}
+
 			matchingHandlers = append(matchingHandlers, handler)
 		}
 	}
@@ -151,10 +155,10 @@ func CreateMatchingHandlerForPattern(tagSpecs []TagSpec, compatibility *Compatib
 		return true
 	}
 
-	return nameTagValue, matchingHandler
+	return nameTagValue, matchingHandler, nil
 }
 
-func createMatchingHandlerForOneTag(spec TagSpec, compatibility *Compatibility) MatchingHandler {
+func createMatchingHandlerForOneTag(spec TagSpec, compatibility *Compatibility) (MatchingHandler, error) {
 	var matchingHandlerCondition func(string) bool
 	allowMatchEmpty := false
 
@@ -171,15 +175,21 @@ func createMatchingHandlerForOneTag(spec TagSpec, compatibility *Compatibility)
 	case MatchOperator:
 		allowMatchEmpty = compatibility.AllowRegexMatchEmpty
 
-		matchRegex := newMatchRegex(spec.Value, compatibility)
+		matchRegex, err := newMatchRegex(spec.Value, compatibility)
+		if err != nil {
+			return nil, err
+		}
 
 		matchingHandlerCondition = func(value string) bool {
 			return matchRegex.MatchString(value)
 		}
 	case NotMatchOperator:
 		allowMatchEmpty = compatibility.AllowRegexMatchEmpty
 
-		matchRegex := newMatchRegex(spec.Value, compatibility)
+		matchRegex, err := newMatchRegex(spec.Value, compatibility)
+		if err != nil {
+			return nil, err
+		}
 
 		matchingHandlerCondition = func(value string) bool {
 			return !matchRegex.MatchString(value)
@@ -199,21 +209,19 @@ func createMatchingHandlerForOneTag(spec TagSpec, compatibility *Compatibility)
 			return matchingHandlerCondition(value)
 		}
 		return allowMatchEmpty && matchEmpty
-	}
+	}, nil
 }
 
-func newMatchRegex(value string, compatibility *Compatibility) *regexp.Regexp {
-	var matchRegex *regexp.Regexp
-
+func newMatchRegex(value string, compatibility *Compatibility) (*regexp.Regexp, error) {
 	if value == "*" {
 		value = ".*"
 	}
 
-	if compatibility.AllowRegexLooseStartMatch {
-		matchRegex = regexp.MustCompile(value)
-	} else {
-		matchRegex = regexp.MustCompile("^" + value)
+	if !compatibility.AllowRegexLooseStartMatch {
+		value = "^" + value
 	}
 
-	return matchRegex
+	matchRegex, err := regexp.Compile(value)
+
+	return matchRegex, err
 }
diff --git a/filter/series_by_tag_pattern_index.go b/filter/series_by_tag_pattern_index.go
@@ -24,7 +24,15 @@ func NewSeriesByTagPatternIndex(
 	withoutStrictNameTagPatternMatchers := make(map[string]MatchingHandler)
 
 	for pattern, tagSpecs := range tagSpecsByPattern {
-		nameTagValue, matchingHandler := CreateMatchingHandlerForPattern(tagSpecs, &compatibility)
+		nameTagValue, matchingHandler, err := CreateMatchingHandlerForPattern(tagSpecs, &compatibility)
+
+		if err != nil {
+			logger.Info().
+				Error(err).
+				String("pattern", pattern).
+				Msg("Failed to create MatchingHandler for pattern")
+			continue
+		}
 
 		if nameTagValue == "" {
 			withoutStrictNameTagPatternMatchers[pattern] = matchingHandler