MCPX MCP Gateway

package metrics import ( "lunar/engine/utils" "regexp" "strings" "sync" "github.com/rs/zerolog/log" "go.opentelemetry.io/otel/attribute" ) const pathLabel = "path" type LabeledEndpointManager struct { mu sync.RWMutex supportedLabelPatterns []string } // NewLabeledEndpointManager creates a new instance of LabeledEndpointManager func NewLabeledEndpointManager(labeledEndpoints []string) *LabeledEndpointManager { mng := &LabeledEndpointManager{} mng.SetLabeledEndpoints(labeledEndpoints) return mng } // SetLabeledEndpoints sets the labeled endpoints func (m *LabeledEndpointManager) SetLabeledEndpoints(labeledEndpoints []string) { m.mu.Lock() defer m.mu.Unlock() m.supportedLabelPatterns = nil for _, label := range labeledEndpoints { m.supportedLabelPatterns = append(m.supportedLabelPatterns, convertPatternToRegex(label)) } log.Info().Msgf("Supported labeled endpoints: %v", labeledEndpoints) } // ExtractLabel checks if the specified URL is defined as a labeled endpoint // and returns the attribute path label if found. func (m *LabeledEndpointManager) ExtractLabel(url string) *attribute.KeyValue { m.mu.RLock() defer m.mu.RUnlock() for _, pattern := range m.supportedLabelPatterns { if matched, _ := regexp.MatchString(pattern, url); matched { if path := utils.ExtractPath(url); path != "" { pathAttribute := attribute.String(pathLabel, path) return &pathAttribute } } } return nil } // convertPatternToRegex converts a URL definition with placeholders (e.g. "{param}") // into a regex string that will match URLs where the value inside the curly braces // can change. In this example, the placeholder is replaced with "([^/]+)", which // matches one or more characters that are not a slash. // // The literal parts of the pattern are escaped so that any regex special characters // (like "." or "-") are treated literally. func convertPatternToRegex(pattern string) string { // regex to find placeholders (everything between "{" and "}") placeholderRegex := regexp.MustCompile(`\{[^}]+\}`) var builder strings.Builder lastIndex := 0 for _, match := range placeholderRegex.FindAllStringIndex(pattern, -1) { start, end := match[0], match[1] builder.WriteString(regexp.QuoteMeta(pattern[lastIndex:start])) // Replace the placeholder with a regex capturing group. // "([^/]+)" matches one or more characters (except the '/') builder.WriteString("([^/]+)") lastIndex = end } // Append any remaining literal text after the last placeholder. builder.WriteString(regexp.QuoteMeta(pattern[lastIndex:])) // Anchor the regex to match the entire string. return "^" + builder.String() + "$" }