[processor][redaction]: redact span event attributes (#38288)

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Ex. Adding a feature - Explain what this achieves.-->
#### Description
Fix redaction processor to redact span event attributes as well.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes
#36633

<!--Describe what testing was performed and which tests were added.-->
#### Testing

Added

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#### Documentation

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Co-authored-by: Dmitrii Anoshin <[email protected]>

Author: VihasMakwana

.chloggen/fix-redaction-processor.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: redactionprocessor
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix redaction processor to redact span event attributes
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [36633]
+
+# (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: []

processor/redactionprocessor/processor.go

@@ -110,10 +110,19 @@ func (s *redaction) processResourceSpan(ctx context.Context, rs ptrace.ResourceS
 
 			// Attributes can also be part of span
 			s.processAttrs(ctx, spanAttrs)
+
+			// Attributes can also be part of span events
+			s.processSpanEvents(ctx, span.Events())
 		}
 	}
 }
 
+func (s *redaction) processSpanEvents(ctx context.Context, events ptrace.SpanEventSlice) {
+	for i := 0; i < events.Len(); i++ {
+		s.processAttrs(ctx, events.At(i).Attributes())
+	}
+}
+
 // processResourceLog processes the log resource and all of its logs and then returns the last
 // view metric context. The context can be used for tests
 func (s *redaction) processResourceLog(ctx context.Context, rl plog.ResourceLogs) {

processor/redactionprocessor/processor_test.go

@@ -567,6 +567,45 @@ func TestProcessAttrsAppliedTwice(t *testing.T) {
 	assert.Equal(t, int64(2), val.Int())
 }
 
+func TestSpanEventRedacted(t *testing.T) {
+	inBatch := ptrace.NewTraces()
+	rs := inBatch.ResourceSpans().AppendEmpty()
+	ils := rs.ScopeSpans().AppendEmpty()
+
+	library := ils.Scope()
+	library.SetName("first-library")
+	span := ils.Spans().AppendEmpty()
+	span.SetName("first-batch-first-span")
+	span.SetTraceID([16]byte{1, 2, 3, 4})
+
+	event := span.Events().AppendEmpty()
+	event.SetName("event-one")
+
+	event.Attributes().PutStr("password", "xyzxyz")
+	event.Attributes().PutStr("username", "foobar")
+
+	config := &Config{
+		AllowAllKeys:  true,
+		BlockedValues: []string{"xyzxyz"},
+		Summary:       "debug",
+	}
+	processor, err := newRedaction(context.TODO(), config, zaptest.NewLogger(t))
+	require.NoError(t, err)
+
+	outTraces, err := processor.processTraces(context.TODO(), inBatch)
+	require.NoError(t, err)
+
+	attr := outTraces.ResourceSpans().At(0).ScopeSpans().At(0).Spans().At(0).Events().At(0).Attributes()
+
+	val, ok := attr.Get("password")
+	require.True(t, ok)
+	assert.Equal(t, "****", val.Str())
+
+	val, ok = attr.Get("username")
+	require.True(t, ok)
+	require.Equal(t, "foobar", val.Str())
+}
+
 // runTest transforms the test input data and passes it through the processor
 func runTest(
 	t *testing.T,