[pkg/translator/loki] Moved labels names normalization to LogToLokiEntry function

Author: mar4uk

.chloggen/pkg-loki-translator-move-label-normalization-to-LogToLokiEntry.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: lokitranslator
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Public method `LogToLokiEntry` from `pkg/loki/translator` now returns normalized (`.` replaced by `_`) label names
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [26093]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

pkg/translator/loki/logs_to_loki.go

@@ -80,16 +80,8 @@ func LogsToLokiRequests(ld plog.Logs, defaultLabelsEnabled map[string]bool) map[
 
 				group.report.NumSubmitted++
 
-				processed := model.LabelSet{}
-				for label := range entry.Labels {
-					// Loki doesn't support dots in label names
-					// labelName is normalized label name to follow Prometheus label names standard
-					labelName := prometheustranslator.NormalizeLabel(string(label))
-					processed[model.LabelName(labelName)] = entry.Labels[label]
-				}
-
 				// create the stream name based on the labels
-				labels := processed.String()
+				labels := entry.Labels.String()
 				if stream, ok := group.streams[labels]; ok {
 					stream.Entries = append(stream.Entries, *entry.Entry)
 					continue
@@ -128,7 +120,7 @@ type PushEntry struct {
 	Labels model.LabelSet
 }
 
-// LogToLokiEntry converts LogRecord into Loki log entry enriched with labels and tenant
+// LogToLokiEntry converts LogRecord into Loki log entry enriched with normalized labels
 func LogToLokiEntry(lr plog.LogRecord, rl pcommon.Resource, scope pcommon.InstrumentationScope, defaultLabelsEnabled map[string]bool) (*PushEntry, error) {
 	// we may remove attributes, so change only our version
 	log := plog.NewLogRecord()
@@ -155,9 +147,17 @@ func LogToLokiEntry(lr plog.LogRecord, rl pcommon.Resource, scope pcommon.Instru
 		return nil, err
 	}
 
+	labels := model.LabelSet{}
+	for label := range mergedLabels {
+		// Loki doesn't support dots in label names
+		// labelName is normalized label name to follow Prometheus label names standard
+		labelName := prometheustranslator.NormalizeLabel(string(label))
+		labels[model.LabelName(labelName)] = mergedLabels[label]
+	}
+
 	return &PushEntry{
 		Entry:  entry,
-		Labels: mergedLabels,
+		Labels: labels,
 	}, nil
 }
 

pkg/translator/loki/logs_to_loki_test.go

@@ -521,7 +521,7 @@ func TestLogToLokiEntry(t *testing.T) {
 				},
 				Labels: model.LabelSet{
 					"exporter":  "OTLP",
-					"host.name": "guarana",
+					"host_name": "guarana",
 				},
 			},
 			err: nil,
@@ -543,7 +543,7 @@ func TestLogToLokiEntry(t *testing.T) {
 				},
 				Labels: model.LabelSet{
 					"exporter":  "OTLP",
-					"host.name": "guarana",
+					"host_name": "guarana",
 				},
 			},
 		},
@@ -565,7 +565,7 @@ func TestLogToLokiEntry(t *testing.T) {
 				},
 				Labels: model.LabelSet{
 					"exporter":  "OTLP",
-					"host.name": "guarana",
+					"host_name": "guarana",
 				},
 			},
 		},