Refactor run_iperf function to parse JSON output and improve error logging

runtest.sh

@@ -71,29 +71,36 @@ run_iperf() {
   local tmp_err
   tmp_err=$(mktemp)
 
-  local result
-  result=$(iperf3 "${args[@]}" 2>"$tmp_err" | jq -r '
-    if .error then
-      "iperf3-error"
-    elif has("end") | not then
-      "no-end"
-    elif .end | has("sum_received") then
-      .end.sum_received.bits_per_second
-    elif .end | has("sum") then
-      .end.sum.bits_per_second
-    else
-      "unexpected-format"
-    end' || echo "execution-failed")
+  local tmp_json
+  tmp_json=$(mktemp)
 
-  if [[ "$result" == "iperf3-error" || "$result" == "no-end" || "$result" == "unexpected-format" || "$result" == "execution-failed" ]]; then
-    echo "$(date -Iseconds),iperf $mode $direction to $target failed with '$result'" >>"$FAILURE_LOG"
+  local result
+  result=$(iperf3 "${args[@]}" -J >"$tmp_json" 2>"$tmp_err")
+
+  parsed=$(jq -r '
+  if .error then
+    "iperf3-error"
+  elif has("end") | not then
+    "no-end"
+  elif .end | has("sum_received") then
+    .end.sum_received.bits_per_second
+  elif .end | has("sum") then
+    .end.sum.bits_per_second
+  else
+    "unexpected-format"
+  end' "$tmp_json" || echo "execution-failed")
+
+  if [[ "$parsed" == "iperf3-error" || "$parsed" == "no-end" || "$parsed" == "unexpected-format" || "$parsed" == "execution-failed" ]]; then
+    timestamp=$(date -Iseconds)
+    echo "$timestamp,iperf $mode $direction to $target failed with '$parsed'" >>"$FAILURE_LOG"
     echo "[stderr] $(cat "$tmp_err")" >>"$FAILURE_LOG"
+    echo "[json] $(cat "$tmp_json")" >>"$FAILURE_LOG"
     echo "0"
   else
-    echo "$result"
+    echo "$parsed"
   fi
 
-  rm -f "$tmp_err"
+  rm -f "$tmp_err" "$tmp_json"
 }
 
 # Start test email