oomparser - new constructor to support streaming of new/current OOM events only.

utils/oomparser/oomparser.go

@@ -151,6 +151,26 @@ func (p *OomParser) StreamOoms(outStream chan<- *OomInstance) {
 	klog.Errorf("exiting analyzeLines. OOM events will not be reported.")
 }
 
+// NewFromNow initializes an OomParser object that returns current OOM events only. In this mode the OomParser object
+// will not send OOM events that occurred before the OomParser object was constructed.
+func NewFromNow() (*OomParser, error) {
+	parser, err := kmsgparser.NewParser()
+	if err != nil {
+		return nil, err
+	}
+	parser.SetLogger(glogAdapter{})
+
+	return newFromNow(parser)
+}
+
+func newFromNow(parser kmsgparser.Parser) (*OomParser, error) {
+	// seek to and set the offset at the end of /dev/kmsg to avoid reporting old OOM events
+	if err := parser.SeekEnd(); err != nil {
+		return nil, err
+	}
+	return &OomParser{parser: parser}, nil
+}
+
 // initializes an OomParser object. Returns an OomParser object and an error.
 func New() (*OomParser, error) {
 	parser, err := kmsgparser.NewParser()

utils/oomparser/oomparser_test.go

@@ -473,11 +473,14 @@ func TestStreamOOMs(t *testing.T) {
 }
 
 type mockKmsgParser struct {
-	messages chan kmsgparser.Message
+	messages      chan kmsgparser.Message
+	seekEndCalled bool
+	seekEndErr    error
 }
 
 func (m *mockKmsgParser) SeekEnd() error {
-	return nil
+	m.seekEndCalled = true
+	return m.seekEndErr
 }
 
 func (m *mockKmsgParser) Parse() <-chan kmsgparser.Message {
@@ -489,3 +492,28 @@ func (m *mockKmsgParser) Close() error {
 	close(m.messages)
 	return nil
 }
+
+func TestNewFromNow(t *testing.T) {
+	mockParser := &mockKmsgParser{
+		messages: make(chan kmsgparser.Message),
+	}
+
+	p, err := newFromNow(mockParser)
+	assert.NoError(t, err)
+	assert.NotNil(t, p)
+	assert.Equal(t, mockParser, p.parser)
+	assert.True(t, mockParser.seekEndCalled, "SeekEnd should have been called")
+}
+
+func TestNewFromNow_SeekEndError(t *testing.T) {
+	expectedErr := fmt.Errorf("seek error")
+	mockParser := &mockKmsgParser{
+		messages:   make(chan kmsgparser.Message),
+		seekEndErr: expectedErr,
+	}
+
+	p, err := newFromNow(mockParser)
+	assert.ErrorIs(t, err, expectedErr)
+	assert.Nil(t, p)
+	assert.True(t, mockParser.seekEndCalled)
+}