[exporter/loki] Use record attributes as log labels (open-telemetry#7569

) * [exporter/loki] Use record attributes as log labels Fixes open-telemetry#6001 Signed-off-by: Juraci Paixão Kröhling <[email protected]> * Fix statement that unknown keys are ignored Signed-off-by: Juraci Paixão Kröhling <[email protected]> Co-authored-by: Anthony Mirabella <[email protected]>
keisku · Feb 10, 2022 · c8215a4 · c8215a4
1 parent 1fb6909
commit c8215a4
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Showing 7 changed files with 168 additions and 9 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ## 💡 Enhancements 💡
 
 - `hostreceiver/memoryscraper`: Migrate the scraper to the mdatagen metrics builder (#7312)
+- `lokiexporter`: Use record attributes as log labels (#7569)
 - `routingprocessor`: Do not err on failure to build exporters (#7423)
 - `apachereceiver`: Update to mdatagen v2 (#7573)
 - `datadogexporter`: Don't send host metadata if hostname is empty (#7426)

diff --git a/exporter/lokiexporter/README.md b/exporter/lokiexporter/README.md
@@ -21,6 +21,11 @@ The following settings are required:
  [Loki label best practices](https://grafana.com/docs/loki/latest/best-practices/) page for 
  additional details on the types of labels you may want to associate with log streams.
 
+- `labels.record` (no default): A map of record attributes to valid Loki label names (must match 
+ "^[a-zA-Z_][a-zA-Z0-9_]*$") allowed to be added as labels to Loki log streams.
+ Record attributes can be: `traceID`, `spanID`, `severity`, `severityN`. These attributes will be added as log labels 
+ and will be removed from the log body.
+
 The following settings can be optionally configured:
 
 - `tenant_id` (no default): The tenant ID used to identify the tenant the logs are associated to. This will set the 
@@ -62,7 +67,10 @@ loki:
  # Allowing 'severity' attribute and not providing a mapping, since the attribute name is a valid Loki label name.
  severity: ""
  http.status_code: "http_status_code" 
-
+ record:
+ # Adds 'traceID' as a log label, seen as 'traceid' in Loki.
+ traceID: "traceid"
+
  headers:
  "X-Custom-Header": "loki_rocks"
 ```

diff --git a/exporter/lokiexporter/config.go b/exporter/lokiexporter/config.go
@@ -55,11 +55,15 @@ type LabelsConfig struct {
 
  // ResourceAttributes are the resource attributes that are allowed to be added as labels on a log stream.
  ResourceAttributes map[string]string `mapstructure:"resource"`
+
+ // RecordAttributes are the attributes from the record that are allowed to be added as labels on a log stream. Possible keys:
+ // traceID, spanID, severity, severityN.
+ RecordAttributes map[string]string `mapstructure:"record"`
 }
 
 func (c *LabelsConfig) validate() error {
- if len(c.Attributes) == 0 && len(c.ResourceAttributes) == 0 {
- return fmt.Errorf("\"labels.attributes\" or \"labels.resource\" must be configured with at least one attribute")
+ if len(c.Attributes) == 0 && len(c.ResourceAttributes) == 0 && len(c.RecordAttributes) == 0 {
+ return fmt.Errorf("\"labels.attributes\", \"labels.resource\", or \"labels.record\" must be configured with at least one attribute")
  }
 
  logRecordNameInvalidErr := "the label `%s` in \"labels.attributes\" is not a valid label name. Label names must match " + model.LabelNameRE.String()
@@ -80,6 +84,17 @@ func (c *LabelsConfig) validate() error {
  }
  }
 
+ possibleRecordAttributes := map[string]bool{
+ "traceID": true,
+ "spanID": true,
+ "severity": true,
+ "severityN": true,
+ }
+ for k := range c.RecordAttributes {
+ if _, found := possibleRecordAttributes[k]; !found {
+ return fmt.Errorf("record attribute %q not recognized, possible values: traceID, spanID, severity, severityN", k)
+ }
+ }
  return nil
 }
 

diff --git a/exporter/lokiexporter/config_test.go b/exporter/lokiexporter/config_test.go
@@ -86,6 +86,9 @@ func TestLoadConfig(t *testing.T) {
  "resource.name": "resource_name",
  "severity": "severity",
  },
+ RecordAttributes: map[string]string{
+ "traceID": "traceid",
+ },
  },
  Format: "body",
  }
@@ -202,7 +205,7 @@ func TestConfig_validate(t *testing.T) {
  ResourceAttributes: nil,
  },
  },
- errorMessage: "\"labels.attributes\" or \"labels.resource\" must be configured with at least one attribute",
+ errorMessage: "\"labels.attributes\", \"labels.resource\", or \"labels.record\" must be configured with at least one attribute",
  shouldError: true,
  },
  {
@@ -221,6 +224,33 @@ func TestConfig_validate(t *testing.T) {
  },
  shouldError: false,
  },
+ {
+ name: "with valid `labels.record`",
+ fields: fields{
+ Endpoint: validEndpoint,
+ Labels: LabelsConfig{
+ RecordAttributes: map[string]string{
+ "traceID": "traceID",
+ "spanID": "spanID",
+ "severity": "severity",
+ "severityN": "severityN",
+ },
+ },
+ },
+ shouldError: false,
+ },
+ {
+ name: "with invalid `labels.record`",
+ fields: fields{
+ Endpoint: validEndpoint,
+ Labels: LabelsConfig{
+ RecordAttributes: map[string]string{
+ "invalid": "Invalid",
+ },
+ },
+ },
+ shouldError: true,
+ },
  }
 
  for _, tt := range tests {
@@ -260,7 +290,7 @@ func TestLabelsConfig_validate(t *testing.T) {
  Attributes: map[string]string{},
  ResourceAttributes: map[string]string{},
  },
- errorMessage: "\"labels.attributes\" or \"labels.resource\" must be configured with at least one attribute",
+ errorMessage: "\"labels.attributes\", \"labels.resource\", or \"labels.record\" must be configured with at least one attribute",
  shouldError: true,
  },
  {

diff --git a/exporter/lokiexporter/exporter.go b/exporter/lokiexporter/exporter.go
@@ -158,6 +158,11 @@ func (l *lokiExporter) logDataToLoki(ld pdata.Logs) (pr *logproto.PushRequest, n
  numDroppedLogs++
  continue
  }
+
+ // now merge the labels based on the record attributes
+ recordLabels := l.convertRecordAttributesToLabels(log)
+ mergedLabels = mergedLabels.Merge(recordLabels)
+
  labels := mergedLabels.String()
  var entry *logproto.Entry
  var err error
@@ -240,25 +245,47 @@ func (l *lokiExporter) convertAttributesToLabels(attributes pdata.AttributeMap,
  return ls
 }
 
+func (l *lokiExporter) convertRecordAttributesToLabels(log pdata.LogRecord) model.LabelSet {
+ ls := model.LabelSet{}
+
+ if val, ok := l.config.Labels.RecordAttributes["traceID"]; ok {
+ ls[model.LabelName(val)] = model.LabelValue(log.TraceID().HexString())
+ }
+
+ if val, ok := l.config.Labels.RecordAttributes["spanID"]; ok {
+ ls[model.LabelName(val)] = model.LabelValue(log.SpanID().HexString())
+ }
+
+ if val, ok := l.config.Labels.RecordAttributes["severity"]; ok {
+ ls[model.LabelName(val)] = model.LabelValue(log.SeverityText())
+ }
+
+ if val, ok := l.config.Labels.RecordAttributes["severityN"]; ok {
+ ls[model.LabelName(val)] = model.LabelValue(log.SeverityNumber().String())
+ }
+
+ return ls
+}
+
 func (l *lokiExporter) convertLogBodyToEntry(lr pdata.LogRecord, res pdata.Resource) (*logproto.Entry, error) {
  var b strings.Builder
 
- if len(lr.SeverityText()) > 0 {
+ if _, ok := l.config.Labels.RecordAttributes["severity"]; !ok && len(lr.SeverityText()) > 0 {
  b.WriteString("severity=")
  b.WriteString(lr.SeverityText())
  b.WriteRune(' ')
  }
- if lr.SeverityNumber() > 0 {
+ if _, ok := l.config.Labels.RecordAttributes["severityN"]; !ok && lr.SeverityNumber() > 0 {
  b.WriteString("severityN=")
  b.WriteString(strconv.Itoa(int(lr.SeverityNumber())))
  b.WriteRune(' ')
  }
- if !lr.TraceID().IsEmpty() {
+ if _, ok := l.config.Labels.RecordAttributes["traceID"]; !ok && !lr.TraceID().IsEmpty() {
  b.WriteString("traceID=")
  b.WriteString(lr.TraceID().HexString())
  b.WriteRune(' ')
  }
- if !lr.SpanID().IsEmpty() {
+ if _, ok := l.config.Labels.RecordAttributes["spanID"]; !ok && !lr.SpanID().IsEmpty() {
  b.WriteString("spanID=")
  b.WriteString(lr.SpanID().HexString())
  b.WriteRune(' ')

diff --git a/exporter/lokiexporter/exporter_test.go b/exporter/lokiexporter/exporter_test.go
@@ -610,3 +610,79 @@ func TestExporter_convertLogtoJSONEntry(t *testing.T) {
  require.NotNil(t, entry)
  require.Equal(t, expEntry, entry)
 }
+
+func TestConvertRecordAttributesToLabels(t *testing.T) {
+ testCases := []struct {
+ desc string
+ lr pdata.LogRecord
+ expected model.LabelSet
+ }{
+ {
+ desc: "traceID",
+ lr: func() pdata.LogRecord {
+ lr := pdata.NewLogRecord()
+ lr.SetTraceID(pdata.NewTraceID([16]byte{1, 2, 3, 4}))
+ return lr
+ }(),
+ expected: func() model.LabelSet {
+ ls := model.LabelSet{}
+ ls[model.LabelName("traceID")] = model.LabelValue("01020304000000000000000000000000")
+ return ls
+ }(),
+ },
+ {
+ desc: "spanID",
+ lr: func() pdata.LogRecord {
+ lr := pdata.NewLogRecord()
+ lr.SetSpanID(pdata.NewSpanID([8]byte{1, 2, 3, 4}))
+ return lr
+ }(),
+ expected: func() model.LabelSet {
+ ls := model.LabelSet{}
+ ls[model.LabelName("spanID")] = model.LabelValue("0102030400000000")
+ return ls
+ }(),
+ },
+ {
+ desc: "severity",
+ lr: func() pdata.LogRecord {
+ lr := pdata.NewLogRecord()
+ lr.SetSeverityText("DEBUG")
+ return lr
+ }(),
+ expected: func() model.LabelSet {
+ ls := model.LabelSet{}
+ ls[model.LabelName("severity")] = model.LabelValue("DEBUG")
+ return ls
+ }(),
+ },
+ {
+ desc: "severityN",
+ lr: func() pdata.LogRecord {
+ lr := pdata.NewLogRecord()
+ lr.SetSeverityNumber(pdata.SeverityNumberDEBUG)
+ return lr
+ }(),
+ expected: func() model.LabelSet {
+ ls := model.LabelSet{}
+ ls[model.LabelName("severityN")] = model.LabelValue(pdata.SeverityNumberDEBUG.String())
+ return ls
+ }(),
+ },
+ }
+ for _, tC := range testCases {
+ t.Run(tC.desc, func(t *testing.T) {
+ exp := newExporter(&Config{
+ Labels: LabelsConfig{
+ RecordAttributes: map[string]string{
+ tC.desc: tC.desc,
+ },
+ },
+ }, componenttest.NewNopTelemetrySettings())
+
+ ls := exp.convertRecordAttributesToLabels(tC.lr)
+
+ assert.Equal(t, tC.expected, ls)
+ })
+ }
+}
diff --git a/exporter/lokiexporter/testdata/config.yaml b/exporter/lokiexporter/testdata/config.yaml
@@ -40,6 +40,8 @@ exporters:
  headers:
  "X-Custom-Header": "loki_rocks"
  labels:
+ record:
+ traceID: traceid
  attributes:
  container.name: "container_name"
  k8s.cluster.name: "k8s_cluster_name"