Duplicate Node Results for Live Traceflow

[antoninbas]

Describe the bug
While running a Live Traceflow, I got the following result:

apiVersion: crd.antrea.io/v1alpha1
kind: Traceflow
metadata:
  creationTimestamp: "2023-03-15T23:29:38Z"
  generation: 1
  labels:
    ui.antrea.io: ""
  name: 0705f0f7-bf12-409e-b5af-60ca50397356
  resourceVersion: "131846"
  uid: 6da11b4e-116d-4992-9825-967d1380a605
spec:
  destination:
    namespace: kube-system
    pod: antrea-ui-9d78f97bc-52lss
  droppedOnly: false
  liveTraffic: true
  packet:
    ipHeader:
      protocol: 6
    transportHeader:
      tcp:
        dstPort: 3000
        flags: 2
        srcPort: 0
  source: {}
  timeout: 30
status:
  capturedPacket:
    dstIP: 10.10.1.24
    ipHeader:
      flags: 2
      protocol: 6
      ttl: 62
    length: 64
    srcIP: 10.10.0.1
    transportHeader:
      tcp:
        dstPort: 3000
        flags: 2
        srcPort: 62012
  phase: Succeeded
  results:
  - node: k8s-node-worker-1
    observations:
    - action: Received
      component: Forwarding
    - action: Delivered
      component: Forwarding
      componentInfo: Output
    timestamp: 1678922981
  - node: k8s-node-worker-1
    observations:
    - action: Received
      component: Forwarding
    - action: Delivered
      component: Forwarding
      componentInfo: Output
    timestamp: 1678922981
  startTime: "2023-03-15T23:29:38Z"

The Traceflow Status is not correct because the Node Result is duplicated.

To Reproduce

To reproduce, one needs to generate 2 connections in the cluster that will match the Live Traceflow filter. Easier way to do that is to use an ICMP Traceflow and run 2 ping commands. However, the 2 connections must run "at the same time", typically with ~1ms of each other, or the Antrea Agent Traceflow Controller will have time to uninstall the Traceflow OVS flows:

antrea/pkg/agent/controller/traceflow/packetin.go

Lines 133 to 136 in 4a80363

	if tfState.liveTraffic && firstPacket {
	// Uninstall the OVS flows after receiving the first packet, to
	// avoid capturing too many matched packets.
	c.ofClient.UninstallTraceflowFlows(tag)

Expected
Status should include a single, non-duplicated, Node Result:

status:
  capturedPacket:
    dstIP: 10.10.1.24
    ipHeader:
      flags: 2
      protocol: 6
      ttl: 62
    length: 64
    srcIP: 10.10.0.1
    transportHeader:
      tcp:
        dstPort: 3000
        flags: 2
        srcPort: 62012
  phase: Succeeded
  results:
  - node: k8s-node-worker-1
    observations:
    - action: Received
      component: Forwarding
    - action: Delivered
      component: Forwarding
      componentInfo: Output
    timestamp: 1678922981

Actual behavior
The Status is incorrect, as shown above.

Versions:
Antrea v1.10 and main branch