style(alerting): rename executor -> handler

pkg/services/alerting/handler.go

@@ -0,0 +1,140 @@
+package alerting
+
+import (
+	"fmt"
+
+	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/log"
+	m "github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/alerting/alertstates"
+	"github.com/grafana/grafana/pkg/tsdb"
+)
+
+var (
+	descriptionFmt = "Actual value: %1.2f for %s. "
+)
+
+type HandlerImpl struct {
+	log log.Logger
+}
+
+func NewHandler() *HandlerImpl {
+	return &HandlerImpl{
+		log: log.New("alerting.executor"),
+	}
+}
+
+func (e *HandlerImpl) Execute(job *AlertJob, resultQueue chan *AlertResult) {
+	timeSeries, err := e.executeQuery(job)
+	if err != nil {
+		resultQueue <- &AlertResult{
+			Error:    err,
+			State:    alertstates.Pending,
+			AlertJob: job,
+		}
+	}
+
+	result := e.evaluateRule(job.Rule, timeSeries)
+	result.AlertJob = job
+	resultQueue <- result
+}
+
+func (e *HandlerImpl) executeQuery(job *AlertJob) (tsdb.TimeSeriesSlice, error) {
+	getDsInfo := &m.GetDataSourceByIdQuery{
+		Id:    job.Rule.Query.DatasourceId,
+		OrgId: job.Rule.OrgId,
+	}
+
+	if err := bus.Dispatch(getDsInfo); err != nil {
+		return nil, fmt.Errorf("Could not find datasource")
+	}
+
+	req := e.GetRequestForAlertRule(job.Rule, getDsInfo.Result)
+	result := make(tsdb.TimeSeriesSlice, 0)
+
+	resp, err := tsdb.HandleRequest(req)
+	if err != nil {
+		return nil, fmt.Errorf("Alerting: GetSeries() tsdb.HandleRequest() error %v", err)
+	}
+
+	for _, v := range resp.Results {
+		if v.Error != nil {
+			return nil, fmt.Errorf("Alerting: GetSeries() tsdb.HandleRequest() response error %v", v)
+		}
+
+		result = append(result, v.Series...)
+	}
+
+	return result, nil
+}
+
+func (e *HandlerImpl) GetRequestForAlertRule(rule *AlertRule, datasource *m.DataSource) *tsdb.Request {
+	e.log.Debug("GetRequest", "query", rule.Query.Query, "from", rule.Query.From, "datasourceId", datasource.Id)
+	req := &tsdb.Request{
+		TimeRange: tsdb.TimeRange{
+			From: "-" + rule.Query.From,
+			To:   rule.Query.To,
+		},
+		Queries: []*tsdb.Query{
+			{
+				RefId: "A",
+				Query: rule.Query.Query,
+				DataSource: &tsdb.DataSourceInfo{
+					Id:       datasource.Id,
+					Name:     datasource.Name,
+					PluginId: datasource.Type,
+					Url:      datasource.Url,
+				},
+			},
+		},
+	}
+
+	return req
+}
+
+func (e *HandlerImpl) evaluateRule(rule *AlertRule, series tsdb.TimeSeriesSlice) *AlertResult {
+	e.log.Debug("Evaluating Alerting Rule", "seriesCount", len(series), "ruleName", rule.Name)
+
+	triggeredAlert := make([]*TriggeredAlert, 0)
+
+	for _, serie := range series {
+		e.log.Debug("Evaluating series", "series", serie.Name)
+		transformedValue, _ := rule.Transformer.Transform(serie)
+
+		critResult := evalCondition(rule.Critical, transformedValue)
+		e.log.Debug("Alert execution Crit", "name", serie.Name, "transformedValue", transformedValue, "operator", rule.Critical.Operator, "level", rule.Critical.Value, "result", critResult)
+		if critResult {
+			triggeredAlert = append(triggeredAlert, &TriggeredAlert{
+				State:       alertstates.Critical,
+				ActualValue: transformedValue,
+				Name:        serie.Name,
+			})
+		}
+
+		warnResult := evalCondition(rule.Warning, transformedValue)
+		e.log.Debug("Alert execution Warn", "name", serie.Name, "transformedValue", transformedValue, "operator", rule.Warning.Operator, "level", rule.Warning.Value, "result", warnResult)
+		if warnResult {
+			triggeredAlert = append(triggeredAlert, &TriggeredAlert{
+				State:       alertstates.Warn,
+				ActualValue: transformedValue,
+				Name:        serie.Name,
+			})
+		}
+	}
+
+	executionState := alertstates.Ok
+	description := ""
+	for _, raised := range triggeredAlert {
+		if raised.State == alertstates.Critical {
+			executionState = alertstates.Critical
+		}
+
+		if executionState != alertstates.Critical && raised.State == alertstates.Warn {
+			executionState = alertstates.Warn
+		}
+
+		description += fmt.Sprintf(descriptionFmt, raised.ActualValue, raised.Name)
+	}
+
+	return &AlertResult{State: executionState, Description: description, TriggeredAlerts: triggeredAlert}
+}