grpc/grpc-go · error

cannot have exclude and a '*' wildcard

Error message

cannot have exclude and a '*' wildcard

What it means

Returned by validateLogEventMethod when an entry in the methods list is the bare wildcard '*' and the Exclude flag is true. The '*' wildcard matches all methods; combining it with exclude would mean 'exclude everything', which is nonsensical for a logging config and is therefore rejected. Inclusion with '*' is valid; exclusion with '*' is not.

Solutions

1. Remove the '*' entry from the methods list when exclude is true; instead list the specific methods you want to exclude.
2. Restructure the config: use an include entry with methods: ["*"] and a separate exclude entry listing the methods to skip.

Example fix

// before
{"client_rpc_events":[{"methods":["*"],"exclude":true}]} // error
// after
{"client_rpc_events":[
  {"methods":["*"]},
  {"methods":["foo.Bar/Sensitive"],"exclude":true}
]}

for _, m := range methods {
    if m == "*" && exclude {
        return fmt.Errorf("cannot use '*' wildcard with exclude=true; list specific methods to exclude")
    }
}

When it happens

Trigger: An observability logging config entry has methods: ["*"] and exclude: true. This combination is detected and rejected during config parsing.

Common situations: Developers try to express 'log everything except certain methods' by inverting the logic (exclude all, then include specific ones), not realizing the config model uses include-lists with specific excludes, not a global exclude-all.

Related errors

• cannot have a leading slash
• method name must be non empty
• / must come in between service and method, only one /
• empty string is not a valid method binary logging config
• grpc: the provided default service config is invalid

AI-assisted analysis of grpc/grpc-go@0c51461d27 (2026-08-11). Data as JSON: /api/errors/df91f71472bda573. Report an issue: GitHub.

Appendix: source

Thrown at gcp/observability/config.go:80

	}
	serviceMethod := strings.Split(method, "/")
	if len(serviceMethod) != 2 {
		return errors.New("/ must come in between service and method, only one /")
	}
	if serviceMethod[1] == "" {
		return errors.New("method name must be non empty")
	}
	if serviceMethod[0] == "*" {
		return errors.New("cannot have service wildcard * i.e. (*/m)")
	}
	return nil
}

func validateLogEventMethod(methods []string, exclude bool) error {
	for _, method := range methods {
		if method == "*" {
			if exclude {
				return errors.New("cannot have exclude and a '*' wildcard")
			}
			continue
		}
		if err := validateMethodString(method); err != nil {
			return fmt.Errorf("invalid method string: %v, err: %v", method, err)
		}
	}
	return nil
}

func validateLoggingEvents(config *config) error {
	if config.CloudLogging == nil {
		return nil
	}
	for _, clientRPCEvent := range config.CloudLogging.ClientRPCEvents {
		if err := validateLogEventMethod(clientRPCEvent.Methods, clientRPCEvent.Exclude); err != nil {
			return fmt.Errorf("error in clientRPCEvent method: %v", err)
		}

View on GitHub (pinned to 0c51461d27)