Propagate logger and metric registry into promql engine

cmd/config_test.go

@@ -10,7 +10,10 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+	"time"
 
+	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
 	"go.uber.org/goleak"
 )
 
@@ -148,3 +151,41 @@ config:
 		}
 	})
 }
+
+func TestEngineFromQueryOptsRegistersMetrics(t *testing.T) {
+	reg := prometheus.NewRegistry()
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+
+	eng := engineFromQueryOpts(queryOpts{
+		engineTimeout:   5 * time.Minute,
+		defaultLookback: 5 * time.Minute,
+	}, logger, reg)
+	if eng == nil {
+		t.Fatal("engine is nil")
+	}
+
+	families, err := reg.Gather()
+	if err != nil {
+		t.Fatalf("gathering metrics: %v", err)
+	}
+
+	want := map[string]dto.MetricType{
+		"thanos_engine_queries":       dto.MetricType_GAUGE,
+		"thanos_engine_queries_total": dto.MetricType_COUNTER,
+	}
+
+	found := make(map[string]bool, len(want))
+	for _, fam := range families {
+		if expectedType, ok := want[fam.GetName()]; ok {
+			if fam.GetType() != expectedType {
+				t.Errorf("metric %s: expected type %s, got %s", fam.GetName(), expectedType, fam.GetType())
+			}
+			found[fam.GetName()] = true
+		}
+	}
+	for name := range want {
+		if !found[name] {
+			t.Errorf("expected metric %s not found in registry", name)
+		}
+	}
+}

cmd/serve.go

@@ -169,8 +169,8 @@ func registerServeApp(app *kingpin.Application) (*kingpin.CmdClause, func(contex
 			cfdb.ExternalLabels(labels.FromMap(opts.query.externalLabels)),
 		)
 
-		setupPromAPI(&g, log, db, opts.promAPI, opts.query)
-		setupThanosAPI(&g, log, db, opts.thanosAPI, opts.query)
+		setupPromAPI(&g, log, db, reg, opts.promAPI, opts.query)
+		setupThanosAPI(&g, log, db, reg, opts.thanosAPI, opts.query)
 		setupInternalAPI(&g, log, reg, opts.internalAPI)
 
 		return g.Run()
@@ -198,16 +198,16 @@ type queryOpts struct {
 	selectChunkPartitionMaxConcurrency int
 }
 
-func engineFromQueryOpts(opts queryOpts) promql.QueryEngine {
+func engineFromQueryOpts(opts queryOpts, logger *slog.Logger, reg prometheus.Registerer) promql.QueryEngine {
 	return engine.New(engine.Opts{
 		DisableDuplicateLabelChecks: true,
 		LogicalOptimizers: []logicalplan.Optimizer{
 			&logicalplan.ProjectionOptimizer{SeriesHashLabel: schema.SeriesHashLabel},
 		},
 
 		EngineOpts: promql.EngineOpts{
-			Logger:                   nil,
-			Reg:                      nil,
+			Logger:                   logger,
+			Reg:                      reg,
 			MaxSamples:               10_000_000,
 			Timeout:                  opts.engineTimeout,
 			NoStepSubqueryIntervalFn: func(int64) int64 { return time.Minute.Milliseconds() },
@@ -218,10 +218,9 @@ func engineFromQueryOpts(opts queryOpts) promql.QueryEngine {
 			EnableDelayedNameRemoval: false,
 		},
 	})
-
 }
 
-func setupThanosAPI(g *run.Group, log *slog.Logger, db *cfdb.DB, opts apiOpts, qOpts queryOpts) {
+func setupThanosAPI(g *run.Group, log *slog.Logger, db *cfdb.DB, reg prometheus.Registerer, opts apiOpts, qOpts queryOpts) {
 	server := grpc.NewServer(
 		grpc.MaxSendMsgSize(math.MaxInt32),
 		grpc.MaxRecvMsgSize(math.MaxInt32),
@@ -234,7 +233,7 @@ func setupThanosAPI(g *run.Group, log *slog.Logger, db *cfdb.DB, opts apiOpts, q
 
 	queryServer := cfgrpc.NewQueryServer(
 		db,
-		engineFromQueryOpts(qOpts),
+		engineFromQueryOpts(qOpts, log, reg),
 		cfgrpc.ConcurrentQueryQuota(qOpts.concurrentQueryQuota),
 		cfgrpc.SelectChunkBytesQuota(qOpts.selectChunkBytesQuota),
 		cfgrpc.SelectRowCountQuota(qOpts.selectRowCountQuota),
@@ -284,8 +283,8 @@ func setupThanosAPI(g *run.Group, log *slog.Logger, db *cfdb.DB, opts apiOpts, q
 	})
 }
 
-func setupPromAPI(g *run.Group, log *slog.Logger, db *cfdb.DB, opts apiOpts, qOpts queryOpts) {
-	handler := cfhttp.NewAPI(db, engineFromQueryOpts(qOpts),
+func setupPromAPI(g *run.Group, log *slog.Logger, db *cfdb.DB, reg prometheus.Registerer, opts apiOpts, qOpts queryOpts) {
+	handler := cfhttp.NewAPI(db, engineFromQueryOpts(qOpts, log, reg),
 		cfhttp.QueryOptions(
 			cfhttp.DefaultStep(qOpts.defaultStep),
 			cfhttp.DefaultLookback(qOpts.defaultLookback),