fmt_pkt: improve scapy-server logging

The daemon will now log to scapy.log file.

Log messages include stats on request processing time as well as any
errors that may happen during processing.

If you'd like to see even more logs (e.g. for debugging purposes), just
pass --verbose to scapy-server.

Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Acked-by: Mark Michelson <mmichels@redhat.com>
Signed-off-by: Mark Michelson <mmichels@redhat.com>

tests/ovn-macros.at

@@ -882,7 +882,10 @@ fmt_pkt() {
 start_scapy_server() {
     pidfile=$ovs_base/scapy.pid
     ctlfile=$ovs_base/scapy.ctl
-    "$top_srcdir"/tests/scapy-server.py --pidfile=$pidfile --unixctl=$ctlfile --detach
+    logfile=$ovs_base/scapy.log
+
+    "$top_srcdir"/tests/scapy-server.py \
+        --pidfile=$pidfile --unixctl=$ctlfile --log-file=$logfile --detach
     on_exit "test -e \"$pidfile\" && ovs-appctl -t $ctlfile exit"
 }
 

tests/scapy-server.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
 import argparse
+import time
 
 import ovs.daemon
 import ovs.unixctl
@@ -24,15 +25,24 @@ def exit(conn, argv, aux):
 
 
 def process(data):
+    start_time = time.perf_counter()
+    vlog.info(f"received payload request: {data}")
     try:
         data = data.replace('\n', '')
         return binascii.hexlify(raw(eval(data))).decode()
-    except Exception:
+    except Exception as e:
+        vlog.exception(f"failed to process payload request: {e}")
         return ""
+    finally:
+        total_time = (time.perf_counter() - start_time) * 1000
+        vlog.info(f"took {total_time:.2f}ms to process payload request")
 
 
 def payload(conn, argv, aux):
-    conn.reply(process(argv[0]))
+    try:
+        conn.reply(process(argv[0]))
+    except Exception as e:
+        vlog.exception(f"failed to reply to payload request: {e}")
 
 
 def main():
@@ -56,6 +66,8 @@ def main():
     ovs.unixctl.command_register("payload", "", 1, 1, payload, None)
     ovs.daemon.daemonize_complete()
 
+    vlog.info("scapy server ready")
+
     poller = ovs.poller.Poller()
     while not exiting:
         server.run()