Alerting: refactor state tracker (#33292)

* set processing time

* merge labels and set on response

* use state cache for adding alerts to rules

* minor cleanup

* add support for NoData and Error results

* rename test

* bring in changes from other PRs tha have been merged

* pr feedback

* add integration test

* close state tracker cleanup on context.Done

* fixup test

* rename state tracker

* set EvaluationDuration on Result

* default labels set as constants

* separate cache and state from manager

* use RWMutex in cache

pkg/services/ngalert/api/api.go

@@ -50,7 +50,7 @@ type API struct {
 	AlertingStore   store.AlertingStore
 	DataProxy       *datasourceproxy.DatasourceProxyService
 	Alertmanager    Alertmanager
-	StateTracker    *state.StateTracker
+	StateManager    *state.Manager
 }
 
 // RegisterAPIEndpoints registers API handlers
@@ -69,7 +69,7 @@ func (api *API) RegisterAPIEndpoints() {
 	api.RegisterPrometheusApiEndpoints(NewForkedProm(
 		api.DatasourceCache,
 		NewLotexProm(proxy, logger),
-		PrometheusSrv{log: logger, stateTracker: api.StateTracker, store: api.RuleStore},
+		PrometheusSrv{log: logger, manager: api.StateManager, store: api.RuleStore},
 	))
 	// Register endpoints for proxing to Cortex Ruler-compatible backends.
 	api.RegisterRulerApiEndpoints(NewForkedRuler(

pkg/services/ngalert/api/api_prometheus.go

@@ -19,9 +19,9 @@ import (
 )
 
 type PrometheusSrv struct {
-	log          log.Logger
-	stateTracker *state.StateTracker
-	store        store.RuleStore
+	log     log.Logger
+	manager *state.Manager
+	store   store.RuleStore
 }
 
 func (srv PrometheusSrv) RouteGetAlertStatuses(c *models.ReqContext) response.Response {
@@ -33,7 +33,7 @@ func (srv PrometheusSrv) RouteGetAlertStatuses(c *models.ReqContext) response.Re
 			Alerts: []*apimodels.Alert{},
 		},
 	}
-	for _, alertState := range srv.stateTracker.GetAll() {
+	for _, alertState := range srv.manager.GetAll() {
 		startsAt := alertState.StartsAt
 		alertResponse.Data.Alerts = append(alertResponse.Data.Alerts, &apimodels.Alert{
 			Labels:      map[string]string(alertState.Labels),
@@ -88,7 +88,7 @@ func (srv PrometheusSrv) RouteGetRuleStatuses(c *models.ReqContext) response.Res
 			EvaluationTime: 0, // TODO: see if we are able to pass this along with evaluation results
 		}
 
-		stateMap := srv.stateTracker.GetStatesByRuleUID()
+		stateMap := srv.manager.GetStatesByRuleUID()
 		for _, rule := range alertRuleQuery.Result {
 			alertingRule := apimodels.AlertingRule{
 				State:       "inactive",