go-sql-driver/mysql · error

invalid value / unknown config name: %s

Error message

invalid value / unknown config name: %s

What it means

Error "invalid value / unknown config name: %s" thrown in go-sql-driver/mysql.

Source

Thrown at dsn.go:210

	} else if cfg.Net == "tcp" {
		cfg.Addr = ensureHavePort(cfg.Addr)
	}

	if cfg.TLS == nil {
		switch cfg.TLSConfig {
		case "false", "":
			// don't set anything
		case "true":
			cfg.TLS = &tls.Config{}
		case "skip-verify":
			cfg.TLS = &tls.Config{InsecureSkipVerify: true}
		case "preferred":
			cfg.TLS = &tls.Config{InsecureSkipVerify: true}
			cfg.AllowFallbackToPlaintext = true
		default:
			cfg.TLS = getTLSConfigClone(cfg.TLSConfig)
			if cfg.TLS == nil {
				return errors.New("invalid value / unknown config name: " + cfg.TLSConfig)
			}
		}
	}

	if cfg.TLS != nil && cfg.TLS.ServerName == "" && !cfg.TLS.InsecureSkipVerify {
		host, _, err := net.SplitHostPort(cfg.Addr)
		if err == nil {
			cfg.TLS.ServerName = host
		}
	}

	if cfg.ServerPubKey != "" {
		cfg.pubKey = getServerPubKey(cfg.ServerPubKey)
		if cfg.pubKey == nil {
			return errors.New("invalid value / unknown server pub key name: " + cfg.ServerPubKey)
		}
	}

View on GitHub (pinned to 03d76c7e07)

Solutions

1. Use a registered TLS config name in tls=<name>, or one of the built-in values: true, false, skip-verify, preferred.
2. Register your custom TLS config first with mysql.RegisterTLSConfig(name, tlsConfig) before opening the connection.

Example fix

mysql.RegisterTLSConfig("custom", &tls.Config{RootCAs: roots})
dsn := "user:pass@tcp(dbhost:3306)/mydb?tls=custom"

When it happens

Trigger: The DSN sets tls=<value> to a name that is not 'true', 'false', 'skip-verify', 'preferred', or a TLS config previously registered with mysql.RegisterTLSConfig.

Common situations: Typo in the tls parameter, or using a custom TLS config name without calling mysql.RegisterTLSConfig(name, config) before opening the connection. Register the config or use one of the built-in values.

AI-assisted analysis of go-sql-driver/mysql@03d76c7e07 (2026-08-07). Data as JSON: /api/errors/9e70c950352350d1. Report an issue: GitHub.