Collect netstat info while running tests

.circleci/config.yml

@@ -280,6 +280,9 @@ jobs:
 
             export GITHUB_SHA=$CIRCLE_SHA1
 
+            ./netstat-script.sh &
+            NS_PID=$!
+
             # Run the tests.
             #
             # The junit.xml file allows CircleCI to display more fine-grained test information
@@ -297,6 +300,9 @@ jobs:
               -m "not remote_cluster" \
               -rA $TEST_SELECTION $EXTRA_PARAMS
 
+            kill $NS_PID
+            awk '/===/ {if (count) print count; print; count=0; next} {count++} END {print count}' $TEST_OUTPUT/netstat.stdout > $TEST_OUTPUT/netstat_stats.stdout
+
             if << parameters.save_perf_report >>; then
               if [[ $CIRCLE_BRANCH == "main" ]]; then
                 export REPORT_FROM="$PERF_REPORT_DIR"

test_runner/netstat-script.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+while true; do
+  echo -n "==== CURRENT TIME:" >> /tmp/test_output/netstat.stdout
+  date +"%T.%N" >> /tmp/test_output/netstat.stdout
+  sudo netstat -vpnoa | grep tcp | sort >> /tmp/test_output/netstat.stdout
+  sleep 0.5
+done