[exporter/azuremonitorexporter] fix: correct parent for span events (#…

…30659)

**Description:** Corrected parent for exported span events.
For details please take a look at the corresponding issue.
I think the change is pretty straight forward - one line added.
However I'm not a go-expert - so there might exist a more elegant
implementation.

**Link to tracking Issue:** #27233

**Testing:** Adapted existing units test.

**Documentation:** n/a

(fyi @pcwiese)

.chloggen/exporter-azuremonitorexporter_fix-parent-of-span-events.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: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: azuremonitorexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Fix: Use correct parentId for span events."
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [27233]
+
+# (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: [user]

exporter/azuremonitorexporter/trace_to_envelope.go

@@ -133,6 +133,7 @@ func spanToEnvelopes(
 		}
 
 		spanEventEnvelope := newEnvelope(span, toTime(spanEvent.Timestamp()).Format(time.RFC3339Nano))
+		spanEventEnvelope.Tags[contracts.OperationParentId] = traceutil.SpanIDToHexOrEmptyString(span.SpanID())
 
 		data := contracts.NewData()
 

exporter/azuremonitorexporter/trace_to_envelope_test.go

@@ -518,7 +518,7 @@ func TestSpanWithEventsToEnvelopes(t *testing.T) {
 		assert.Equal(t, targetEnvelopeName, envelope.Name)
 		assert.Equal(t, toTime(spanEvent.Timestamp()).Format(time.RFC3339Nano), envelope.Time)
 		assert.Equal(t, defaultTraceIDAsHex, envelope.Tags[contracts.OperationId])
-		assert.Equal(t, defaultParentSpanIDAsHex, envelope.Tags[contracts.OperationParentId])
+		assert.Equal(t, defaultSpanIDAsHex, envelope.Tags[contracts.OperationParentId])
 		assert.Equal(t, defaultServiceNamespace+"."+defaultServiceName, envelope.Tags[contracts.CloudRole])
 		assert.Equal(t, defaultServiceInstance, envelope.Tags[contracts.CloudRoleInstance])
 		assert.NotNil(t, envelope.Data)