[DebugExporter] Add EventName from LogRecord to output (#11967)

#### Description
1. Adds event name from LogRecord to debug exporter.
2. Also modified the example config file to include logs too. (It only
had traces/metrics). Not really required for this change, but hope that
is okay to club into same PR!

#### Link to tracking issue
Fixes #11966 

#### Testing
Manually tested with Otel client that exported a LogRecord with event
name and without event name.

(1st time contributor here, still learning the process.)

---------

Co-authored-by: Trask Stalnaker <[email protected]>
Co-authored-by: Alex Boten <[email protected]>

Author: 3 people

.chloggen/add-eventname-debug-exporter.yaml

@@ -0,0 +1,25 @@
+# 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. otlpreceiver)
+component: debugexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Add EventName to debug exporter for Logs. EventName was added as top-level field in the LogRecord from 1.5.0 of proto definition."
+
+# One or more tracking issues or pull requests related to the change
+issues: [11966]
+
+# (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:
+
+# 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: []

examples/local/otel-config.yaml

@@ -33,5 +33,9 @@ service:
       receivers: [otlp]
       processors: [memory_limiter, batch]
       exporters: [debug]
+    logs:
+      receivers: [otlp]
+      processors: [memory_limiter, batch]
+      exporters: [debug]
 
   extensions: [zpages]

exporter/debugexporter/internal/otlptext/logs.go

@@ -38,6 +38,9 @@ func (textLogsMarshaler) MarshalLogs(ld plog.Logs) ([]byte, error) {
 				buf.logEntry("Timestamp: %s", lr.Timestamp())
 				buf.logEntry("SeverityText: %s", lr.SeverityText())
 				buf.logEntry("SeverityNumber: %s(%d)", lr.SeverityNumber(), lr.SeverityNumber())
+				if lr.EventName() != "" {
+					buf.logEntry("EventName: %s", lr.EventName())
+				}
 				buf.logEntry("Body: %s", valueToString(lr.Body()))
 				buf.logAttributes("Attributes", lr.Attributes())
 				buf.logEntry("Trace ID: %s", lr.TraceID())

exporter/debugexporter/internal/otlptext/logs_test.go

@@ -39,6 +39,25 @@ func TestLogsText(t *testing.T) {
 			in:   testdata.GenerateLogs(2),
 			out:  "two_records.out",
 		},
+		{
+			name: "log_with_event_name",
+			in: func() plog.Logs {
+				ls := plog.NewLogs()
+				l := ls.ResourceLogs().AppendEmpty().ScopeLogs().AppendEmpty().LogRecords().AppendEmpty()
+				l.SetTimestamp(pcommon.NewTimestampFromTime(time.Date(2020, 2, 11, 20, 26, 13, 789, time.UTC)))
+				l.SetSeverityNumber(plog.SeverityNumberInfo)
+				l.SetSeverityText("Info")
+				l.SetEventName("event_name")
+				l.Body().SetStr("This is a log message")
+				attrs := l.Attributes()
+				attrs.PutStr("app", "server")
+				attrs.PutInt("instance_num", 1)
+				l.SetSpanID([8]byte{0x01, 0x02, 0x04, 0x08})
+				l.SetTraceID([16]byte{0x08, 0x04, 0x02, 0x01})
+				return ls
+			}(),
+			out: "log_with_event_name.out",
+		},
 		{
 			name: "logs_with_embedded_maps",
 			in: func() plog.Logs {

exporter/debugexporter/internal/otlptext/testdata/logs/log_with_event_name.out

@@ -0,0 +1,18 @@
+ResourceLog #0
+Resource SchemaURL: 
+ScopeLogs #0
+ScopeLogs SchemaURL: 
+InstrumentationScope  
+LogRecord #0
+ObservedTimestamp: 1970-01-01 00:00:00 +0000 UTC
+Timestamp: 2020-02-11 20:26:13.000000789 +0000 UTC
+SeverityText: Info
+SeverityNumber: Info(9)
+EventName: event_name
+Body: Str(This is a log message)
+Attributes:
+     -> app: Str(server)
+     -> instance_num: Int(1)
+Trace ID: 08040201000000000000000000000000
+Span ID: 0102040800000000
+Flags: 0