From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Thu, 10 Apr 2025 14:04:04 +0000 (+0200)
Subject: dnsdist: Add a regression test for cache lookups w/ unavailable cache-only backends
X-Git-Tag: dnsdist-2.0.0-alpha2~82^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a36a3e9bfc3a50735cbe63252fadd46ba984ba55;p=thirdparty%2Fpdns.git

dnsdist: Add a regression test for cache lookups w/ unavailable cache-only backends
---

diff --git a/regression-tests.dnsdist/test_Caching.py b/regression-tests.dnsdist/test_Caching.py
index 0f0f1195b4..76c85059d0 100644
--- a/regression-tests.dnsdist/test_Caching.py
+++ b/regression-tests.dnsdist/test_Caching.py
@@ -1151,15 +1151,19 @@ class TestCachingStale(DNSDistTest):
     _consoleKey = DNSDistTest.generateConsoleKey()
     _consoleKeyB64 = base64.b64encode(_consoleKey).decode('ascii')
     _staleCacheTTL = 60
-    _config_params = ['_staleCacheTTL', '_consoleKeyB64', '_consolePort', '_testServerPort']
+    _config_params = ['_staleCacheTTL', '_consoleKeyB64', '_consolePort', '_testServerPort', '_testServerPort']
     _config_template = """
     pc = newPacketCache(100, {maxTTL=86400, minTTL=1, temporaryFailureTTL=0, staleTTL=%d})
     getPool(""):setCache(pc)
+    getPool("tcp-only"):setCache(pc)
     setStaleCacheEntriesTTL(600)
     setKey("%s")
     controlSocket("127.0.0.1:%d")
     newServer{address="127.0.0.1:%d"}
+    newServer{address="127.0.0.1:%d", tcpOnly=true, pool='tcp-only'}
+    addAction(QNameRule('stale-tcp-only.cache.tests.powerdns.com.'), PoolAction('tcp-only'))
     """
+
     def testCacheStale(self):
         """
         Cache: Cache entry, set backend down, get stale entry
@@ -1207,6 +1211,53 @@ class TestCachingStale(DNSDistTest):
 
         self.assertEqual(total, misses)
 
+    def testCacheStaleTCPOnly(self):
+        """
+        Cache: Cache entry from TCP-only backend, set backend down, get stale entry
+
+        """
+        misses = 0
+        ttl = 2
+        name = 'stale-tcp-only.cache.tests.powerdns.com.'
+        query = dns.message.make_query(name, 'A', 'IN')
+        response = dns.message.make_response(query)
+        rrset = dns.rrset.from_text(name,
+                                    ttl,
+                                    dns.rdataclass.IN,
+                                    dns.rdatatype.A,
+                                    '127.0.0.1')
+        response.answer.append(rrset)
+
+        # Miss
+        (receivedQuery, receivedResponse) = self.sendUDPQuery(query, response)
+        self.assertTrue(receivedQuery)
+        self.assertTrue(receivedResponse)
+        receivedQuery.id = query.id
+        self.assertEqual(query, receivedQuery)
+        self.assertEqual(response, receivedResponse)
+        misses += 1
+
+        # next queries should hit the cache
+        (_, receivedResponse) = self.sendUDPQuery(query, response=None, useQueue=False)
+        self.assertEqual(receivedResponse, response)
+
+        # ok, we mark the backend as down
+        self.sendConsoleCommand("getServer(1):setDown()")
+        # and we wait for the entry to expire
+        time.sleep(ttl + 1)
+
+        # we should get a cached, stale, entry
+        (_, receivedResponse) = self.sendUDPQuery(query, response=None, useQueue=False)
+        self.assertEqual(receivedResponse, response)
+        for an in receivedResponse.answer:
+            self.assertEqual(an.ttl, self._staleCacheTTL)
+
+        total = 0
+        for key in self._responsesCounter:
+            total += self._responsesCounter[key]
+
+        self.assertEqual(total, misses)
+
 class TestCachingStaleExpunged(DNSDistTest):
 
     _consoleKey = DNSDistTest.generateConsoleKey()