Cannot parse OpenVPN client tIme

[erdnaxe]

When querying the exporter, I get:

openvpn_exporter[801]: 2021/08/14 13:11:20 Failed to scrape showq socket: parsing time "2021-08-14 13:11:20" as "Mon Jan 2 15:04:05 2006": cannot parse "2021-08-14 13:11:20" as "Mon"

I believe this is caused by

openvpn_exporter/exporters/openvpn_exporter.go

Lines 303 to 313 in 9d468c0

	// Time at which the statistics were updated.
	location, _ := time.LoadLocation("Local")
	timeParser, err := time.ParseInLocation("Mon Jan 2 15:04:05 2006", fields[1], location)
	if err != nil {
	return err
	}
	ch <- prometheus.MustNewConstMetric(
	e.openvpnStatusUpdateTimeDesc,
	prometheus.GaugeValue,
	float64(timeParser.Unix()),
	statusPath)

[erdnaxe]

Proposition, although they may be a cleaner way to do this:

	// Time at which the statistics were updated.
	location, _ := time.LoadLocation("Local")
	timeParser, err := time.ParseInLocation("Mon Jan 2 15:04:05 2006", fields[1], location)
	if err != nil {
		// Try ISO8601 format (OpenVPN 2.5+)
		timeParser, err = time.ParseInLocation("2006-01-02 15:04:05", fields[1], location)
	}
	if err != nil {
		return err
	}
	ch <- prometheus.MustNewConstMetric(
		e.openvpnStatusUpdateTimeDesc,
		prometheus.GaugeValue,
		float64(timeParser.Unix()),
		statusPath)

[erdnaxe]

This has been broken with OpenVPN 2.5.0, Change timestamps in file-based logging to ISO 8601 time format. in https://community.openvpn.net/openvpn/wiki/ChangesInOpenvpn25