Fix sync_ban.py (#10323)

The log message tracked by this test was changed.

chain/client/src/sync/header.rs

@@ -238,6 +238,7 @@ impl HeaderSync {
                                 if now > *stalling_ts + self.stall_ban_timeout
                                     && *highest_height == peer.highest_block_height
                                 {
+                                    // This message is used in sync_ban.py test. Consider checking there as well if you change it.
                                     // The peer is one of the peers with the highest height, but we consider the peer stalling.
                                     warn!(target: "sync", "Sync: ban a peer: {}, for not providing enough headers. Peer's height:  {}", peer.peer_info, peer.highest_block_height);
                                     // Ban the peer, which blocks all interactions with the peer for some time.

pytest/lib/utils.py

@@ -111,6 +111,10 @@ def check(self, pattern: str) -> bool:
         """Check whether the pattern can be found in the logs."""
         return pattern in self._read_file()
 
+    def check_re(self, pattern: str) -> bool:
+        """Check whether the regex pattern can be found in the logs."""
+        return re.search(pattern, self._read_file()) != None
+
     def reset(self) -> None:
         """Resets log offset to beginning of the file."""
         self.offset = 0

pytest/tests/sanity/sync_ban.py

@@ -22,7 +22,7 @@
 TIMEOUT = 300
 EPOCH_LENGTH = 50
 
-BAN_STRING = 'ban a fraudulent peer'
+BAN_STRING = 'ban a peer: [^\n]*, for not providing enough headers'
 
 
 class Handler(ProxyHandler):
@@ -108,7 +108,7 @@ async def handle(self, msg, fr, to):
         assert time.time() - start < TIMEOUT
 
         if should_ban:
-            if tracker1.check(BAN_STRING):
+            if tracker1.check_re(BAN_STRING):
                 break
         else:
             cur_height = nodes[0].get_latest_block().height
@@ -122,8 +122,8 @@ async def handle(self, msg, fr, to):
                 break
         time.sleep(2)
 
-    if not should_ban and (tracker0.check(BAN_STRING) or
-                           tracker1.check(BAN_STRING)):
+    if not should_ban and (tracker0.check_re(BAN_STRING) or
+                           tracker1.check_re(BAN_STRING)):
         assert False, "unexpected ban of peers"
 
     # logger.info('shutting down')