fix(test): measure the time of the last captured packet, not when fil…

…e writing completes

This decouples the test from disk throughputs for larger files.
Reducing the overall capture time to 1s also helps not capturing gigabytes of data on loopback.

src/pcap/test/integration/agent_api_client.go

@@ -421,22 +421,27 @@ var _ = Describe("Using LocalResolver", func() {
 					SnapLen: 65000,
 				}
 
+				var stop time.Time
 				go func() {
-					time.Sleep(5 * time.Second)
+					time.Sleep(1 * time.Second)
 					GinkgoWriter.Println("sending Stop")
+					stop = time.Now().UTC()
 					client.StopRequest()
 				}()
 
 				err = client.ProcessCapture(ctx, endpointRequest, captureOptions, cancel)
 				Expect(err).To(BeNil())
 				validateAge := func(packets []gopacket.Packet) {
-					maxAge := 10 * time.Second
+					maxAge := 5 * time.Second
 					Expect(packets).ToNot(BeEmpty())
 
-					firstTimestamp := packets[0].Metadata().Timestamp
-					Expect(firstTimestamp).ToNot(BeNil())
-					delta := time.Since(firstTimestamp)
-					Expect(delta).To(BeNumerically("<", maxAge), "Expected %s to be %s before %s", firstTimestamp, maxAge, time.Now())
+					lastTimestamp := packets[len(packets)-1].Metadata().Timestamp
+					Expect(lastTimestamp).ToNot(BeNil())
+					delta := lastTimestamp.Sub(stop)
+					logger.Sugar().Infof("Captured %d packets. Last timestamp: %v, %v after stop command", len(packets), lastTimestamp, delta)
+					Expect(delta).To(BeNumerically("<", maxAge), "Expected %s to be up to %s after %s", lastTimestamp, maxAge, stop)
+					Expect(delta).To(BeNumerically(">", 0), "Expected delay of stop command and last packet to be > 0")
+
 				}
 				validatePcapFile(file, validateAge)
 			})