Persist time series viewer metrics (#1752)

* WIP persisting time series viewer metrics. Closes #1478

* Remove unused var, move around initial collection

metrics/metrics.go

@@ -13,15 +13,11 @@ import (
 // How often we poll for updates.
 const metricsPollingInterval = 1 * time.Minute
 
-var _getStatus func() models.Status
-
 // CollectedMetrics stores different collected + timestamped values.
 type CollectedMetrics struct {
 	CPUUtilizations  []timestampedValue `json:"cpu"`
 	RAMUtilizations  []timestampedValue `json:"memory"`
 	DiskUtilizations []timestampedValue `json:"disk"`
-
-	Viewers []timestampedValue `json:"-"`
 }
 
 // Metrics is the shared Metrics instance.
@@ -29,8 +25,6 @@ var Metrics *CollectedMetrics
 
 // Start will begin the metrics collection and alerting.
 func Start(getStatus func() models.Status) {
-	_getStatus = getStatus
-
 	host := data.GetServerURL()
 	if host == "" {
 		host = "unknown"
@@ -72,7 +66,6 @@ func Start(getStatus func() models.Status) {
 
 	Metrics = new(CollectedMetrics)
 	go startViewerCollectionMetrics()
-	handlePolling()
 
 	for range time.Tick(metricsPollingInterval) {
 		handlePolling()