From 9fbd1dbc04ab4f867620189472149bda0d1ec271 Mon Sep 17 00:00:00 2001
From: Marc Semrau <msemrau@blues.com>
Date: Mon, 26 Feb 2024 14:57:48 -0700
Subject: [PATCH] Add support for additional stats in DataDog upload

---
 datadog.go     | 14 +++++++++++++-
 http-canary.go |  2 ++
 stats.go       | 28 +++++++++++++++++++++++++++-
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/datadog.go b/datadog.go
index bec4bae..c557f7e 100644
--- a/datadog.go
+++ b/datadog.go
@@ -25,7 +25,7 @@ func (list statOccurrence) Less(i, j int) bool {
 }
 
 // Write new stats to DataDog
-func datadogUploadStats(hostname string, bucketSecs int64, addedStats map[string][]StatsStat) (err error) {
+func datadogUploadStats(hostname string, bucketSecs int64, addedStats map[string][]StatsStat, additionalStats map[string]AdditionalStat) (err error) {
 
 	// Generate the list of aggregated stats
 	aggregatedStats := statsAggregate(addedStats, bucketSecs)
@@ -160,6 +160,18 @@ func datadogUploadStats(hostname string, bucketSecs int64, addedStats map[string
 	}
 	seriesArray = append(seriesArray, series)
 
+	for _, stat := range additionalStats {
+		series = datadog.Series{Metric: "notehub." + hostname + "." + stat.Name, Type: datadog.PtrString("gauge")}
+		for _, value := range stat.Values {
+			point := []*float64{
+				datadog.PtrFloat64(float64(value.Time)),
+				datadog.PtrFloat64(float64(value.Value)),
+			}
+			series.Points = append(series.Points, point)
+		}
+		seriesArray = append(seriesArray, series)
+	}
+
 	// Submit the metrics
 	ctx := context.Background()
 	ctx = context.WithValue(ctx, datadog.ContextServerVariables, map[string]string{"site": Config.DatadogSite})
diff --git a/http-canary.go b/http-canary.go
index 09366a2..52fbca6 100644
--- a/http-canary.go
+++ b/http-canary.go
@@ -38,6 +38,8 @@ var device map[string]deviceContext
 // Canary handler
 func inboundWebCanaryHandler(httpRsp http.ResponseWriter, httpReq *http.Request) {
 
+	AddAdditionalStat("canary_called", 1)
+
 	// Exit
 	if Config.CanaryDisabled {
 		return
diff --git a/stats.go b/stats.go
index 79d7d79..e0ac3b8 100644
--- a/stats.go
+++ b/stats.go
@@ -80,6 +80,30 @@ var statsLock sync.Mutex
 var stats map[string]HostStats
 var statsServiceVersions map[string]string
 
+type AdditionalStat struct {
+	Name	string
+	Values	[]StatValue
+}
+
+type StatValue struct {
+	Time	int64
+	Value	int64
+}
+
+var AdditionalStats map[string]AdditionalStat
+
+func AddAdditionalStat(name string, value int64) {
+    stat, ok := AdditionalStats[name]
+    if !ok {
+        // If the stat does not exist, create it
+        stat = AdditionalStat{Name: name}
+    }
+    // Add the new value
+    stat.Values = append(stat.Values, StatValue{Time: todayTime(), Value: value})
+    // Put the stat back into the map
+    AdditionalStats[name] = stat
+}
+
 // Trace
 const addStatsTrace = true
 
@@ -709,7 +733,9 @@ func statsUpdateHost(hostname string, hostaddr string, reload bool) (ss serviceS
 	// If this is just the initial set of stats that were being loaded from the file system, ignore it,
 	// else write the stats to datadog
 	if len(addedStats) > 0 && time.Now().UTC().Unix() > statsInitCompleted+60 {
-		datadogUploadStats(hostname, ss.BucketSecs, addedStats)
+		datadogUploadStats(hostname, ss.BucketSecs, addedStats, AdditionalStats)
+		// Clean up the additional stats so it doesn't keep growing.
+		AdditionalStats = map[string]AdditionalStat{}
 	}
 
 	// Done