otel: add support for per tenant configuration for mapping otlp data to loki format

clients/pkg/promtail/targets/lokipush/pushtarget.go

@@ -111,7 +111,7 @@ func (t *PushTarget) run() error {
 func (t *PushTarget) handleLoki(w http.ResponseWriter, r *http.Request) {
 	logger := util_log.WithContext(r.Context(), util_log.Logger)
 	userID, _ := tenant.TenantID(r.Context())
-	req, err := push.ParseRequest(logger, userID, r, nil, push.ParseLokiRequest)
+	req, err := push.ParseRequest(logger, userID, r, nil, nil, push.ParseLokiRequest)
 	if err != nil {
 		level.Warn(t.logger).Log("msg", "failed to parse incoming push request", "err", err.Error())
 		http.Error(w, err.Error(), http.StatusBadRequest)

pkg/distributor/http.go

@@ -34,7 +34,7 @@ func (d *Distributor) pushHandler(w http.ResponseWriter, r *http.Request, pushRe
 		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}
-	req, err := push.ParseRequest(logger, tenantID, r, d.tenantsRetention, pushRequestParser)
+	req, err := push.ParseRequest(logger, tenantID, r, d.tenantsRetention, d.validator.Limits, pushRequestParser)
 	if err != nil {
 		if d.tenantConfigs.LogPushRequest(tenantID) {
 			level.Debug(logger).Log(

pkg/distributor/limits.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/grafana/loki/pkg/compactor/retention"
 	"github.com/grafana/loki/pkg/distributor/shardstreams"
+	"github.com/grafana/loki/pkg/loghttp/push"
 )
 
 // Limits is an interface for distributor limits/related configs
@@ -30,4 +31,5 @@ type Limits interface {
 	AllowStructuredMetadata(userID string) bool
 	MaxStructuredMetadataSize(userID string) int
 	MaxStructuredMetadataCount(userID string) int
+	OTLPConfig(userID string) push.OTLPConfig
 }

pkg/loghttp/push/otlp.go

@@ -25,28 +25,9 @@ import (
 const (
 	pbContentType       = "application/x-protobuf"
 	gzipContentEncoding = "gzip"
+	attrServiceName     = "service.name"
 )
 
-var blessedAttributes = []string{
-	"service.name",
-	"service.namespace",
-	"service.instance.id",
-	"deployment.environment",
-	"cloud.region",
-	"cloud.availability_zone",
-	"k8s.cluster.name",
-	"k8s.namespace.name",
-	"k8s.pod.name",
-	"k8s.container.name",
-	"container.name",
-	"k8s.replicaset.name",
-	"k8s.deployment.name",
-	"k8s.statefulset.name",
-	"k8s.daemonset.name",
-	"k8s.cronjob.name",
-	"k8s.job.name",
-}
-
 var blessedAttributesNormalized = make([]string, len(blessedAttributes))
 
 func init() {
@@ -62,14 +43,14 @@ func newPushStats() *Stats {
 	}
 }
 
-func ParseOTLPRequest(userID string, r *http.Request, tenantsRetention TenantsRetention) (*logproto.PushRequest, *Stats, error) {
+func ParseOTLPRequest(userID string, r *http.Request, tenantsRetention TenantsRetention, limits Limits) (*logproto.PushRequest, *Stats, error) {
 	stats := newPushStats()
 	otlpLogs, err := extractLogs(r, stats)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	req := otlpToLokiPushRequest(otlpLogs, userID, tenantsRetention, stats)
+	req := otlpToLokiPushRequest(otlpLogs, userID, tenantsRetention, limits.OTLPConfig(userID), stats)
 	return req, stats, nil
 }
 
@@ -120,7 +101,7 @@ func extractLogs(r *http.Request, pushStats *Stats) (plog.Logs, error) {
 	return req.Logs(), nil
 }
 
-func otlpToLokiPushRequest(ld plog.Logs, userID string, tenantsRetention TenantsRetention, stats *Stats) *logproto.PushRequest {
+func otlpToLokiPushRequest(ld plog.Logs, userID string, tenantsRetention TenantsRetention, otlpConfig OTLPConfig, stats *Stats) *logproto.PushRequest {
 	if ld.LogRecordCount() == 0 {
 		return &logproto.PushRequest{}
 	}
@@ -131,39 +112,38 @@ func otlpToLokiPushRequest(ld plog.Logs, userID string, tenantsRetention Tenants
 	for i := 0; i < rls.Len(); i++ {
 		sls := rls.At(i).ScopeLogs()
 		res := rls.At(i).Resource()
+		resAttrs := res.Attributes()
 
-		flattenedResourceAttributes := labels.NewBuilder(logproto.FromLabelAdaptersToLabels(attributesToLabels(res.Attributes(), "")))
-		// service.name is a required Resource Attribute. If it is not present, we will set it to "unknown_service".
-		if flattenedResourceAttributes.Get("service_name") == "" {
-			flattenedResourceAttributes = flattenedResourceAttributes.Set("service_name", "unknown_service")
+		if v, _ := resAttrs.Get(attrServiceName); v.AsString() == "" {
+			resAttrs.PutStr(attrServiceName, "unknown_service")
 		}
+		resourceAttributesAsStructuredMetadata := make(push.LabelsAdapter, 0, resAttrs.Len())
+		streamLabels := make(model.LabelSet, len(blessedAttributesNormalized))
 
-		if dac := res.DroppedAttributesCount(); dac != 0 {
-			flattenedResourceAttributes = flattenedResourceAttributes.Set("resource_dropped_attributes_count", fmt.Sprintf("%d", dac))
-		}
+		resAttrs.Range(func(k string, v pcommon.Value) bool {
+			action := otlpConfig.ActionForResourceAttribute(k)
+			if action == Drop {
+				return true
+			}
 
-		// copy blessed attributes to stream labels
-		streamLabels := make(model.LabelSet, len(blessedAttributesNormalized))
-		for _, ba := range blessedAttributesNormalized {
-			v := flattenedResourceAttributes.Get(ba)
-			if v == "" {
-				continue
+			attributeAsLabels := attributeToLabels(k, v, "")
+			if action == IndexLabel {
+				for _, lbl := range attributeAsLabels {
+					streamLabels[model.LabelName(lbl.Name)] = model.LabelValue(lbl.Value)
+				}
+			} else if action == StructuredMetadata {
+				resourceAttributesAsStructuredMetadata = append(resourceAttributesAsStructuredMetadata, attributeAsLabels...)
 			}
-			streamLabels[model.LabelName(ba)] = model.LabelValue(v)
 
-			// remove the blessed attributes copied to stream labels
-			flattenedResourceAttributes.Del(ba)
-		}
+			return true
+		})
 
 		if err := streamLabels.Validate(); err != nil {
 			stats.errs = append(stats.errs, fmt.Errorf("invalid labels: %w", err))
 			continue
 		}
 		labelsStr := streamLabels.String()
 
-		// convert the remaining resource attributes to structured metadata
-		resourceAttributesAsStructuredMetadata := logproto.FromLabelsToLabelAdapters(flattenedResourceAttributes.Labels())
-
 		lbs := modelLabelsSetToLabelsList(streamLabels)
 		if _, ok := pushRequestsByStream[labelsStr]; !ok {
 			pushRequestsByStream[labelsStr] = logproto.Stream{
@@ -178,6 +158,7 @@ func otlpToLokiPushRequest(ld plog.Logs, userID string, tenantsRetention Tenants
 		for j := 0; j < sls.Len(); j++ {
 			scope := sls.At(j).Scope()
 			logs := sls.At(j).LogRecords()
+			scopeAttrs := scope.Attributes()
 
 			// it would be rare to have multiple scopes so if the entries slice is empty, pre-allocate it for the number of log entries
 			if cap(pushRequestsByStream[labelsStr].Entries) == 0 {
@@ -187,7 +168,20 @@ func otlpToLokiPushRequest(ld plog.Logs, userID string, tenantsRetention Tenants
 			}
 
 			// use fields and attributes from scope as structured metadata
-			scopeAttributesAsStructuredMetadata := attributesToLabels(scope.Attributes(), "")
+			scopeAttributesAsStructuredMetadata := make(push.LabelsAdapter, 0, scopeAttrs.Len()+3)
+			scopeAttrs.Range(func(k string, v pcommon.Value) bool {
+				action := otlpConfig.ActionForScopeAttribute(k)
+				if action == Drop {
+					return true
+				}
+
+				attributeAsLabels := attributeToLabels(k, v, "")
+				if action == StructuredMetadata {
+					scopeAttributesAsStructuredMetadata = append(scopeAttributesAsStructuredMetadata, attributeAsLabels...)
+				}
+
+				return true
+			})
 
 			if scopeName := scope.Name(); scopeName != "" {
 				scopeAttributesAsStructuredMetadata = append(scopeAttributesAsStructuredMetadata, push.LabelAdapter{
@@ -213,7 +207,7 @@ func otlpToLokiPushRequest(ld plog.Logs, userID string, tenantsRetention Tenants
 			for k := 0; k < logs.Len(); k++ {
 				log := logs.At(k)
 
-				entry := otlpLogToPushEntry(log)
+				entry := otlpLogToPushEntry(log, otlpConfig)
 
 				// if entry.StructuredMetadata doesn't have capacity to add resource and scope attributes, make a new slice with enough capacity
 				attributesAsStructuredMetadataLen := len(resourceAttributesAsStructuredMetadata) + len(scopeAttributesAsStructuredMetadata)
@@ -251,9 +245,23 @@ func otlpToLokiPushRequest(ld plog.Logs, userID string, tenantsRetention Tenants
 }
 
 // otlpLogToPushEntry converts an OTLP log record to a Loki push.Entry.
-func otlpLogToPushEntry(log plog.LogRecord) push.Entry {
+func otlpLogToPushEntry(log plog.LogRecord, otlpConfig OTLPConfig) push.Entry {
 	// copy log attributes and all the fields from log(except log.Body) to structured metadata
-	structuredMetadata := attributesToLabels(log.Attributes(), "")
+	logAttrs := log.Attributes()
+	structuredMetadata := make(push.LabelsAdapter, 0, logAttrs.Len()+7)
+	logAttrs.Range(func(k string, v pcommon.Value) bool {
+		action := otlpConfig.ActionForLogAttribute(k)
+		if action == Drop {
+			return true
+		}
+
+		attributeAsLabels := attributeToLabels(k, v, "")
+		if action == StructuredMetadata {
+			structuredMetadata = append(structuredMetadata, attributeAsLabels...)
+		}
+
+		return true
+	})
 
 	// if log.Timestamp() is 0, we would have already stored log.ObservedTimestamp as log timestamp so no need to store again in structured metadata
 	if log.Timestamp() != 0 && log.ObservedTimestamp() != 0 {
@@ -316,25 +324,39 @@ func attributesToLabels(attrs pcommon.Map, prefix string) push.LabelsAdapter {
 	}
 
 	attrs.Range(func(k string, v pcommon.Value) bool {
-		keyWithPrefix := k
-		if prefix != "" {
-			keyWithPrefix = prefix + "_" + k
-		}
-		keyWithPrefix = prometheustranslator.NormalizeLabel(keyWithPrefix)
-
-		typ := v.Type()
-		if typ == pcommon.ValueTypeMap {
-			labelsAdapter = append(labelsAdapter, attributesToLabels(v.Map(), keyWithPrefix)...)
-		} else {
-			labelsAdapter = append(labelsAdapter, push.LabelAdapter{Name: keyWithPrefix, Value: v.AsString()})
-		}
-
+		labelsAdapter = append(labelsAdapter, attributeToLabels(k, v, prefix)...)
 		return true
 	})
 
 	return labelsAdapter
 }
 
+func attributeToLabels(k string, v pcommon.Value, prefix string) push.LabelsAdapter {
+	var labelsAdapter push.LabelsAdapter
+
+	keyWithPrefix := k
+	if prefix != "" {
+		keyWithPrefix = prefix + "_" + k
+	}
+	keyWithPrefix = prometheustranslator.NormalizeLabel(keyWithPrefix)
+
+	typ := v.Type()
+	if typ == pcommon.ValueTypeMap {
+		mv := v.Map()
+		labelsAdapter = make(push.LabelsAdapter, 0, mv.Len())
+		mv.Range(func(k string, v pcommon.Value) bool {
+			labelsAdapter = append(labelsAdapter, attributeToLabels(k, v, keyWithPrefix)...)
+			return true
+		})
+	} else {
+		labelsAdapter = push.LabelsAdapter{
+			push.LabelAdapter{Name: keyWithPrefix, Value: v.AsString()},
+		}
+	}
+
+	return labelsAdapter
+}
+
 func timestampFromLogRecord(lr plog.LogRecord) time.Time {
 	if lr.Timestamp() != 0 {
 		return time.Unix(0, int64(lr.Timestamp()))