[route_check]: Add truncation indicator and mismatch summary counts (#4587)

* [route_check]: Add truncation indicator and mismatch summary counts

* Add PRINT_MSG_TRUNCATION_SUFFIX constant and truncation marker within PRINT_MSG_LEN_MAX budget
* Extract summarize_results() helper for per-namespace mismatch counts
* Add test_logging_truncation_indicator with coverage for suffix, short msg, and edge cases

Signed-off-by: Bojun-Feng <bojundf@gmail.com>

* [route_check]: Fix flake8 E501 line length violations

* Break long print_message calls to fit within 120 char limit

Signed-off-by: Bojun-Feng <bojundf@gmail.com>

* [route_check]: Fix flake8 E128 continuation line indent

* Align continuation lines to opening parenthesis

Signed-off-by: Bojun-Feng <bojundf@gmail.com>

---------

Signed-off-by: Bojun-Feng <bojundf@gmail.com>

Author: Bojun-Feng

scripts/route_check.py

@@ -76,6 +76,7 @@
 MAX_SCAN_INTERVAL = 3600    # An hour
 
 PRINT_MSG_LEN_MAX = 1000
+PRINT_MSG_TRUNCATION_SUFFIX = " ... (truncated)"
 
 FRR_CHECK_RETRIES = 3
 FRR_WAIT_TIME = 15
@@ -129,15 +130,23 @@ def print_message(lvl, *args, write_to_stdout=True):
     :param lvl: Log level for this message as ERR/INFO/DEBUG
     :param args: message as list of strings or convertible to string
     :param write_to_stdout: print the message to stdout if set to true
-    :return None
+    :return msg string (may be truncated)
     """
     msg = ""
+    truncated = False
     if (lvl <= report_level):
         for arg in args:
             rem_len = PRINT_MSG_LEN_MAX - len(msg)
             if rem_len <= 0:
+                truncated = True
                 break
-            msg += str(arg)[0:rem_len]
+            s = str(arg)
+            if len(s) > rem_len:
+                truncated = True
+            msg += s[0:rem_len]
+
+        if truncated and PRINT_MSG_LEN_MAX > len(PRINT_MSG_TRUNCATION_SUFFIX):
+            msg = msg[:PRINT_MSG_LEN_MAX - len(PRINT_MSG_TRUNCATION_SUFFIX)] + PRINT_MSG_TRUNCATION_SUFFIX
 
         if write_to_stdout:
             print(msg)
@@ -966,6 +975,16 @@ def check_routes_for_namespace(namespace):
     return results, adds, deletes
 
 
+def summarize_results(results):
+    """
+    Summarize mismatch results by counting entries per namespace/category.
+    :param results: dict of {namespace: {category: [entries]}}
+    :return dict of {namespace: {category: count}}
+    """
+    return {ns: {k: len(v) for k, v in entries.items()}
+            for ns, entries in results.items()}
+
+
 def check_routes(namespace):
     """
     Main function to parallelize route checks across all namespaces.
@@ -1000,6 +1019,8 @@ def check_routes(namespace):
                 return -1, results
 
     if results:
+        print_message(syslog.LOG_WARNING, "Route mismatch counts: ",
+                      json.dumps(summarize_results(results), separators=(",", ":")))
         print_message(syslog.LOG_WARNING, "Failure results: {",  json.dumps(results, indent=4), "}")
         print_message(syslog.LOG_WARNING, "Failed. Look at reported mismatches above")
         print_message(syslog.LOG_WARNING, "add: ", json.dumps(all_adds, indent=4))
@@ -1070,6 +1091,8 @@ def check_sids(namespace):
                 return -1, results
 
     if results:
+        print_message(syslog.LOG_WARNING, "SID mismatch counts: ",
+                      json.dumps(summarize_results(results), separators=(",", ":")))
         print_message(syslog.LOG_WARNING, "SIDs Check Failure results: {",  json.dumps(results, indent=4), "}")
         return -1, results
     else:

tests/route_check_test.py

@@ -340,6 +340,24 @@ def test_logging(self):
         msg = route_check.print_message(syslog.LOG_ERR, "a", "b", "c", "d", "e", "f")
         assert len(msg) == 5
 
+    def test_logging_truncation_indicator(self):
+        # Test truncation indicator with realistic PRINT_MSG_LEN_MAX
+        route_check.PRINT_MSG_LEN_MAX = 50
+        msg = route_check.print_message(syslog.LOG_ERR, "x" * 100)
+        assert len(msg) == 50
+        assert msg.endswith(" ... (truncated)")
+
+        # Short message should not have truncation indicator
+        msg = route_check.print_message(syslog.LOG_ERR, "short")
+        assert msg == "short"
+        assert " ... (truncated)" not in msg
+
+        # When PRINT_MSG_LEN_MAX is smaller than suffix, no suffix appended
+        route_check.PRINT_MSG_LEN_MAX = 5
+        msg = route_check.print_message(syslog.LOG_ERR, "abcdefghi")
+        assert len(msg) == 5
+        assert " ... (truncated)" not in msg
+
     def test_mitigate_routes(self, mock_dbs):
         namespace = DEFAULTNS
         missed_frr_rt = [{'prefix': '192.168.0.1', 'protocol': 'bgp'}]