chore: move otlp handling to a separate file

pkg/receive/handler.go

@@ -256,6 +256,18 @@ func NewHandler(logger log.Logger, o *Options) *Handler {
 		),
 	)
 
+	h.router.Post(
+		"/v1/metrics",
+		instrf(
+			"otlp",
+			readyf(
+				middleware.RequestID(
+					http.HandlerFunc(h.receiveOTLPHTTP),
+				),
+			),
+		),
+	)
+
 	statusAPI := statusapi.New(statusapi.Options{
 		GetStats: h.getStats,
 		Registry: h.options.Registry,

pkg/receive/handler_otlp.go

@@ -0,0 +1,228 @@
+// Copyright (c) The Thanos Authors.
+// Licensed under the Apache License 2.0.
+
+package receive
+
+import (
+	"context"
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	"github.com/pkg/errors"
+	"github.com/prometheus/prometheus/prompb"
+	"github.com/prometheus/prometheus/storage/remote"
+	otlptranslator "github.com/prometheus/prometheus/storage/remote/otlptranslator/prometheusremotewrite"
+	"github.com/thanos-io/thanos/pkg/store/labelpb"
+	tprompb "github.com/thanos-io/thanos/pkg/store/storepb/prompb"
+	"github.com/thanos-io/thanos/pkg/tenancy"
+	"github.com/thanos-io/thanos/pkg/tracing"
+	"net/http"
+	"strconv"
+)
+
+func (h *Handler) receiveOTLPHTTP(w http.ResponseWriter, r *http.Request) {
+	var err error
+	span, ctx := tracing.StartSpan(r.Context(), "receive_http")
+	span.SetTag("receiver.mode", string(h.receiverMode))
+	defer span.Finish()
+
+	tenant, err := tenancy.GetTenantFromHTTP(r, h.options.TenantHeader, h.options.DefaultTenantID, h.options.TenantField)
+	if err != nil {
+		level.Error(h.logger).Log("msg", "error getting tenant from HTTP", "err", err)
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	tLogger := log.With(h.logger, "tenant", tenant)
+	span.SetTag("tenant", tenant)
+
+	writeGate := h.Limiter.WriteGate()
+	tracing.DoInSpan(r.Context(), "receive_write_gate_ismyturn", func(ctx context.Context) {
+		err = writeGate.Start(r.Context())
+	})
+	defer writeGate.Done()
+	if err != nil {
+		level.Error(tLogger).Log("err", err, "msg", "internal server error")
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	under, err := h.Limiter.HeadSeriesLimiter().isUnderLimit(tenant)
+	if err != nil {
+		level.Error(tLogger).Log("msg", "error while limiting", "err", err.Error())
+	}
+
+	// Fail request fully if tenant has exceeded set limit.
+	if !under {
+		http.Error(w, "tenant is above active series limit", http.StatusTooManyRequests)
+		return
+	}
+
+	requestLimiter := h.Limiter.RequestLimiter()
+	// io.ReadAll dynamically adjust the byte slice for read data, starting from 512B.
+	// Since this is receive hot path, grow upfront saving allocations and CPU time.
+	// TODO Fix getting rid of the memory limiting stuff for now
+	//compressed := bytes.Buffer{}
+	//if r.ContentLength >= 0 {
+	//	if !requestLimiter.AllowSizeBytes(tenant, r.ContentLength) {
+	//		http.Error(w, "write request too large", http.StatusRequestEntityTooLarge)
+	//		return
+	//	}
+	//	compressed.Grow(int(r.ContentLength))
+	//} else {
+	//	compressed.Grow(512)
+	//}
+	//_, err = io.Copy(&compressed, r.Body)
+	//if err != nil {
+	//	http.Error(w, errors.Wrap(err, "read compressed request body").Error(), http.StatusInternalServerError)
+	//	return
+	//}
+	//reqBuf, err := s2.Decode(nil, compressed.Bytes())
+	//if err != nil {
+	//	level.Error(tLogger).Log("msg", "snappy decode error", "err", err)
+	//	http.Error(w, errors.Wrap(err, "snappy decode error").Error(), http.StatusBadRequest)
+	//	return
+	//}
+	//
+	//if !requestLimiter.AllowSizeBytes(tenant, int64(len(reqBuf))) {
+	//	http.Error(w, "write request too large", http.StatusRequestEntityTooLarge)
+	//	return
+	//}
+
+	// NOTE: Due to zero copy ZLabels, Labels used from WriteRequests keeps memory
+	// from the whole request. Ensure that we always copy those when we want to
+	// store them for longer time.
+	// TODO Fix getting rid of this for now
+	//var wreq prompb.WriteRequest
+	//if err := proto.Unmarshal(reqBuf, &wreq); err != nil {
+	//	http.Error(w, err.Error(), http.StatusBadRequest)
+	//	return
+	//}
+
+	req, err := remote.DecodeOTLPWriteRequest(r)
+	if err != nil {
+		level.Error(h.logger).Log("msg", "Error decoding remote write request", "err", err.Error())
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	// TODO expose otlptranslator.Settings as config options
+	prwMetricsMap, errs := otlptranslator.FromMetrics(req.Metrics(), otlptranslator.Settings{
+		AddMetricSuffixes: true,
+	})
+	if errs != nil {
+		level.Warn(h.logger).Log("msg", "Error translating OTLP metrics to Prometheus write request", "err", errs)
+	}
+
+	prwMetrics := make([]tprompb.TimeSeries, 0, 100)
+
+	for _, ts := range prwMetricsMap {
+		t := tprompb.TimeSeries{
+			Labels:    makeLabels(ts.Labels),
+			Samples:   makeSamples(ts.Samples),
+			Exemplars: makeExemplars(ts.Exemplars),
+			// TODO handle historgrams
+		}
+		prwMetrics = append(prwMetrics, t)
+	}
+
+	wreq := tprompb.WriteRequest{
+		Timeseries: prwMetrics,
+		// TODO Handle metadata, requires thanos receiver support ingesting metadata
+		//Metadata: otlptranslator.OtelMetricsToMetadata(),
+	}
+
+	rep := uint64(0)
+	// If the header is empty, we assume the request is not yet replicated.
+	if replicaRaw := r.Header.Get(h.options.ReplicaHeader); replicaRaw != "" {
+		if rep, err = strconv.ParseUint(replicaRaw, 10, 64); err != nil {
+			http.Error(w, "could not parse replica header", http.StatusBadRequest)
+			return
+		}
+	}
+
+	// Exit early if the request contained no data. We don't support metadata yet. We also cannot fail here, because
+	// this would mean lack of forward compatibility for remote write proto.
+	if len(wreq.Timeseries) == 0 {
+		// TODO(yeya24): Handle remote write metadata.
+		if len(wreq.Metadata) > 0 {
+			// TODO(bwplotka): Do we need this error message?
+			level.Debug(tLogger).Log("msg", "only metadata from client; metadata ingestion not supported; skipping")
+			return
+		}
+		level.Debug(tLogger).Log("msg", "empty remote write request; client bug or newer remote write protocol used?; skipping")
+		return
+	}
+
+	if !requestLimiter.AllowSeries(tenant, int64(len(wreq.Timeseries))) {
+		http.Error(w, "too many timeseries", http.StatusRequestEntityTooLarge)
+		return
+	}
+
+	totalSamples := 0
+	for _, timeseries := range wreq.Timeseries {
+		totalSamples += len(timeseries.Samples)
+	}
+	if !requestLimiter.AllowSamples(tenant, int64(totalSamples)) {
+		http.Error(w, "too many samples", http.StatusRequestEntityTooLarge)
+		return
+	}
+
+	// Apply relabeling configs.
+	h.relabel(&wreq)
+	if len(wreq.Timeseries) == 0 {
+		level.Debug(tLogger).Log("msg", "remote write request dropped due to relabeling.")
+		return
+	}
+
+	responseStatusCode := http.StatusOK
+	if err := h.handleRequest(ctx, rep, tenant, &wreq); err != nil {
+		level.Debug(tLogger).Log("msg", "failed to handle request", "err", err.Error())
+		switch errors.Cause(err) {
+		case errNotReady:
+			responseStatusCode = http.StatusServiceUnavailable
+		case errUnavailable:
+			responseStatusCode = http.StatusServiceUnavailable
+		case errConflict:
+			responseStatusCode = http.StatusConflict
+		case errBadReplica:
+			responseStatusCode = http.StatusBadRequest
+		default:
+			level.Error(tLogger).Log("err", err, "msg", "internal server error")
+			responseStatusCode = http.StatusInternalServerError
+		}
+		http.Error(w, err.Error(), responseStatusCode)
+	}
+	h.writeTimeseriesTotal.WithLabelValues(strconv.Itoa(responseStatusCode), tenant).Observe(float64(len(wreq.Timeseries)))
+	h.writeSamplesTotal.WithLabelValues(strconv.Itoa(responseStatusCode), tenant).Observe(float64(totalSamples))
+}
+
+func makeLabels(in []prompb.Label) []labelpb.ZLabel {
+	out := make([]labelpb.ZLabel, 0, len(in))
+	for _, l := range in {
+		out = append(out, labelpb.ZLabel{Name: l.Name, Value: l.Value})
+	}
+	return out
+}
+
+func makeSamples(in []prompb.Sample) []tprompb.Sample {
+	out := make([]tprompb.Sample, 0, len(in))
+	for _, s := range in {
+		out = append(out, tprompb.Sample{
+			Value:     s.Value,
+			Timestamp: s.Timestamp,
+		})
+	}
+	return out
+}
+
+func makeExemplars(in []prompb.Exemplar) []tprompb.Exemplar {
+	out := make([]tprompb.Exemplar, 0, len(in))
+	for _, e := range in {
+		out = append(out, tprompb.Exemplar{
+			Labels:    makeLabels(e.Labels),
+			Value:     e.Value,
+			Timestamp: e.Timestamp,
+		})
+	}
+	return out
+}