Function buildConnectOneConfigs

pgconn/pgconn.go:180–242

buildConnectOneConfigs resolves hostnames and builds a list of connectOneConfigs to try connecting to. It returns a slice of successfully resolved connectOneConfigs and a slice of errors. It is possible for both slices to contain values if some hosts were successfully resolved and others were not.

(ctx context.Context, config *Config)

// slice of successfully resolved connectOneConfigs and a slice of errors. It is possible for both slices to contain
// values if some hosts were successfully resolved and others were not.
func buildConnectOneConfigs(ctx context.Context, config *Config) ([]*connectOneConfig, []error) {
	// Simplify usage by treating primary config and fallbacks the same.
	fallbackConfigs := []*FallbackConfig{
		{
			Host:      config.Host,
			Port:      config.Port,
			TLSConfig: config.TLSConfig,
		},
	}
	fallbackConfigs = append(fallbackConfigs, config.Fallbacks...)

	var configs []*connectOneConfig

	var allErrors []error

	for _, fb := range fallbackConfigs {
		// skip resolve for unix sockets
		if isAbsolutePath(fb.Host) {
			network, address := NetworkAddress(fb.Host, fb.Port)
			configs = append(configs, &connectOneConfig{
				network:          network,
				address:          address,
				originalHostname: fb.Host,
				tlsConfig:        fb.TLSConfig,
			})

			continue
		}

		ips, err := config.LookupFunc(ctx, fb.Host)
		if err != nil {
			allErrors = append(allErrors, err)
			continue
		}

		for _, ip := range ips {
			splitIP, splitPort, err := net.SplitHostPort(ip)
			if err == nil {
				port, err := strconv.ParseUint(splitPort, 10, 16)
				if err != nil {
					return nil, []error{fmt.Errorf("error parsing port (%s) from lookup: %w", splitPort, err)}
				}
				network, address := NetworkAddress(splitIP, uint16(port))
				configs = append(configs, &connectOneConfig{
					network:          network,
					address:          address,
					originalHostname: fb.Host,
					tlsConfig:        fb.TLSConfig,
				})
			} else {
				network, address := NetworkAddress(ip, fb.Port)
				configs = append(configs, &connectOneConfig{
					network:          network,
					address:          address,
					originalHostname: fb.Host,
					tlsConfig:        fb.TLSConfig,
				})
			}