Remove unit from setting because of Aurora

Signed-off-by: Angus Dippenaar <angusdippenaar@gmail.com>

cmd/postgres_exporter/pg_setting.go

@@ -23,6 +23,13 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
+var (
+	settingUnits = []string{
+		"ms", "s", "min", "h", "d",
+		"B", "kB", "MB", "GB", "TB",
+	}
+)
+
 // Query the pg_settings view containing runtime variables
 func querySettings(ch chan<- prometheus.Metric, server *Server) error {
 	level.Debug(logger).Log("msg", "Querying pg_setting view", "server", server)
@@ -93,9 +100,24 @@ func (s *pgSetting) metric(labels prometheus.Labels) prometheus.Metric {
 	return prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, val)
 }
 
+// Removes units from any of the setting values.
+// This is mostly because of a irregularity regarding AWS RDS Aurora
+// https://github.com/prometheus-community/postgres_exporter/issues/619
+func (s *pgSetting) sanitizeValue() {
+	for _, unit := range settingUnits {
+		if strings.HasSuffix(s.setting, unit) {
+			endPos := len(s.setting) - len(unit) - 1
+			s.setting = s.setting[:endPos]
+			return
+		}
+	}
+}
+
 // TODO: fix linter override
 // nolint: nakedret
 func (s *pgSetting) normaliseUnit() (val float64, unit string, err error) {
+	s.sanitizeValue()
+
 	val, err = strconv.ParseFloat(s.setting, 64)
 	if err != nil {
 		return val, unit, fmt.Errorf("Error converting setting %q value %q to float: %s", s.name, s.setting, err)