Add support for different stale status than Unknown

Signed-off-by: Knut Ahlers <knut@ahlers.me>

client/client.go

@@ -107,7 +107,7 @@ type PostMetricInput struct {
 	// Default: `604800`
 	Expires int64 `json:"expires,omitempty"`
 
-	// Time in seconds when to switch to `Unkown` state of there is no update (Valid: `0 < x < 604800`)
+	// Time in seconds when to switch to stale state of there is no update (Valid: `0 < x < 604800`)
 	// Default: 3600
 	Freshness int64 `json:"freshness,omitempty"`
 
@@ -122,6 +122,10 @@ type PostMetricInput struct {
 	// If set to true the value of the metric is not shown on the dashboard
 	// Default: false
 	HideValue bool `json:"hide_value,omitempty"`
+
+	// If set this status will be set when the metric gets stale (no updates within freshness time range
+	// Default: "Unknown"
+	StalenessStatus string `json:"staleness_status,omitifempty"`
 }
 
 func (p *PostMetricInput) validate() error {

structs.go

@@ -11,6 +11,8 @@ import (
 	"github.com/Luzifer/mondash/storage"
 )
 
+const defaultStalenessStatus = "Unknown"
+
 type dashboard struct {
 	DashboardID string           `json:"-"`
 	APIKey      string           `json:"api_key"`
@@ -66,6 +68,7 @@ type dashboardMetric struct {
 	HideValue       bool                   `json:"hide_value"`
 	HistoricalData  dashboardMetricHistory `json:"history,omitifempty"`
 	Meta            dashboardMetricMeta    `json:"meta,omitifempty"`
+	StalenessStatus string                 `json:"staleness_status,omitifempty"`
 }
 
 type dashboardMetricStatus struct {
@@ -86,7 +89,7 @@ type dashboardMetricHistory []dashboardMetricStatus
 
 func newDashboardMetric() *dashboardMetric {
 	return &dashboardMetric{
-		Status:         "Unknown",
+		Status:         defaultStalenessStatus,
 		Expires:        604800,
 		Freshness:      3600,
 		HistoricalData: dashboardMetricHistory{},
@@ -171,7 +174,10 @@ func (dm *dashboardMetric) StatisticalStatus() string {
 
 func (dm *dashboardMetric) PreferredStatus() string {
 	if dm.Meta.LastUpdate.Before(time.Now().Add(-1 * time.Duration(dm.Freshness) * time.Second)) {
-		return "Unknown"
+		if dm.StalenessStatus == "" {
+			return defaultStalenessStatus
+		}
+		return dm.StalenessStatus
 	}
 
 	if dm.IgnoreMAD {
@@ -289,7 +295,7 @@ func (dm dashboardMetric) GetHistoryBar() []historyBarSegment {
 		segLength int
 		segments  = []historyBarSegment{}
 		segStart  time.Time
-		status    = "Unknown"
+		status    = defaultStalenessStatus
 	)
 
 	for _, point = range dm.HistoricalData {