Alerting: Repurpose rule testing endpoint to return potential alerts (#69755)

* Alerting: Repurpose rule testing endpoint to return potential alerts

This feature replaces the existing no-longer in-use grafana ruler testing API endpoint /api/v1/rule/test/grafana. The new endpoint returns a list of potential alerts created by the given alert rule, including built-in + interpolated labels and annotations.

The key priority of this endpoint is that it is intended to be as true as possible to what would be generated by the ruler except that the resulting alerts are not filtered to only Resolved / Firing and ready to be sent.

This means that the endpoint will, among other things:

- Attach static annotations and labels from the rule configuration to the alert instances.
- Attach dynamic annotations from the datasource to the alert instances.
- Attach built-in labels and annotations created by the Grafana Ruler (such as alertname and grafana_folder) to the alert instances.
- Interpolate templated annotations / labels and accept allowed template functions.

pkg/services/ngalert/api/api_testing.go

@@ -8,7 +8,10 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/benbjohnson/clock"
+	"github.com/grafana/alerting/models"
 	"github.com/grafana/grafana-plugin-sdk-go/data"
+	amv2 "github.com/prometheus/alertmanager/api/v2/models"
 
 	"github.com/grafana/grafana/pkg/api/response"
 	"github.com/grafana/grafana/pkg/infra/log"
@@ -16,10 +19,12 @@ import (
 	contextmodel "github.com/grafana/grafana/pkg/services/contexthandler/model"
 	"github.com/grafana/grafana/pkg/services/datasources"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
+	"github.com/grafana/grafana/pkg/services/folder"
 	apimodels "github.com/grafana/grafana/pkg/services/ngalert/api/tooling/definitions"
 	"github.com/grafana/grafana/pkg/services/ngalert/backtesting"
 	"github.com/grafana/grafana/pkg/services/ngalert/eval"
 	ngmodels "github.com/grafana/grafana/pkg/services/ngalert/models"
+	"github.com/grafana/grafana/pkg/services/ngalert/state"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util"
 )
@@ -33,46 +38,73 @@ type TestingApiSrv struct {
 	cfg             *setting.UnifiedAlertingSettings
 	backtesting     *backtesting.Engine
 	featureManager  featuremgmt.FeatureToggles
+	appUrl          *url.URL
 }
 
-func (srv TestingApiSrv) RouteTestGrafanaRuleConfig(c *contextmodel.ReqContext, body apimodels.TestRulePayload) response.Response {
-	if body.Type() != apimodels.GrafanaBackend || body.GrafanaManagedCondition == nil {
-		return errorToResponse(backendTypeDoesNotMatchPayloadTypeError(apimodels.GrafanaBackend, body.Type().String()))
+// RouteTestGrafanaRuleConfig returns a list of potential alerts for a given rule configuration. This is intended to be
+// as true as possible to what would be generated by the ruler except that the resulting alerts are not filtered to
+// only Resolved / Firing and ready to send.
+func (srv TestingApiSrv) RouteTestGrafanaRuleConfig(c *contextmodel.ReqContext, body apimodels.PostableExtendedRuleNodeExtended) response.Response {
+	rule, err := validateRuleNode(
+		&body.Rule,
+		body.RuleGroup,
+		srv.cfg.BaseInterval,
+		c.OrgID,
+		&folder.Folder{
+			OrgID: c.OrgID,
+			UID:   body.NamespaceUID,
+			Title: body.NamespaceTitle,
+		},
+		func(condition ngmodels.Condition) error {
+			return srv.evaluator.Validate(eval.NewContext(c.Req.Context(), c.SignedInUser), condition)
+		},
+		srv.cfg,
+	)
+	if err != nil {
+		return ErrResp(http.StatusBadRequest, err, "")
 	}
 
-	queries := AlertQueriesFromApiAlertQueries(body.GrafanaManagedCondition.Data)
-
-	if !authorizeDatasourceAccessForRule(&ngmodels.AlertRule{Data: queries}, func(evaluator accesscontrol.Evaluator) bool {
+	if !authorizeDatasourceAccessForRule(rule, func(evaluator accesscontrol.Evaluator) bool {
 		return accesscontrol.HasAccess(srv.accessControl, c)(evaluator)
 	}) {
 		return errorToResponse(fmt.Errorf("%w to query one or many data sources used by the rule", ErrAuthorization))
 	}
 
-	evalCond := ngmodels.Condition{
-		Condition: body.GrafanaManagedCondition.Condition,
-		Data:      queries,
-	}
-	ctx := eval.NewContext(c.Req.Context(), c.SignedInUser)
-
-	conditionEval, err := srv.evaluator.Create(ctx, evalCond)
+	evaluator, err := srv.evaluator.Create(eval.NewContext(c.Req.Context(), c.SignedInUser), rule.GetEvalCondition())
 	if err != nil {
-		return ErrResp(http.StatusBadRequest, err, "invalid condition")
+		return ErrResp(http.StatusBadRequest, err, "Failed to build evaluator for queries and expressions")
 	}
 
-	now := body.GrafanaManagedCondition.Now
-	if now.IsZero() {
-		now = timeNow()
-	}
-
-	evalResults, err := conditionEval.Evaluate(c.Req.Context(), now)
+	now := time.Now()
+	results, err := evaluator.Evaluate(c.Req.Context(), now)
 	if err != nil {
-		return ErrResp(500, err, "Failed to evaluate the rule")
+		return ErrResp(http.StatusInternalServerError, err, "Failed to evaluate queries")
 	}
 
-	frame := evalResults.AsDataFrame()
-	return response.JSONStreaming(http.StatusOK, util.DynMap{
-		"instances": []*data.Frame{&frame},
-	})
+	cfg := state.ManagerCfg{
+		Metrics:       nil,
+		ExternalURL:   srv.appUrl,
+		InstanceStore: nil,
+		Images:        &backtesting.NoopImageService{},
+		Clock:         clock.New(),
+		Historian:     nil,
+	}
+	manager := state.NewManager(cfg)
+	includeFolder := !srv.cfg.ReservedLabels.IsReservedLabelDisabled(models.FolderTitleLabel)
+	transitions := manager.ProcessEvalResults(
+		c.Req.Context(),
+		now,
+		rule,
+		results,
+		state.GetRuleExtraLabels(rule, body.NamespaceTitle, includeFolder),
+	)
+
+	alerts := make([]*amv2.PostableAlert, 0, len(transitions))
+	for _, alertState := range transitions {
+		alerts = append(alerts, state.StateToPostableAlert(alertState.State, srv.appUrl))
+	}
+
+	return response.JSON(http.StatusOK, alerts)
 }
 
 func (srv TestingApiSrv) RouteTestRuleConfig(c *contextmodel.ReqContext, body apimodels.TestRulePayload, datasourceUID string) response.Response {