Merge ~adam-collard/maas:plug-memory-leak-attempt into maas:master

[Adam Collard]

Limit size of certificate cache, align calls for better hits.

[Jack Lloyd-Walters (lloydwaltersj)]

+1

review: Approve

[MAAS Lander (maas-lander)]

UNIT TESTS
-b plug-memory-leak-attempt lp:~adam-collard/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: 0b02b4c1018030971c6bad37c19f576714c4498d

review: Approve

diff --git a/src/maasserver/forms/tests/test_pods.py b/src/maasserver/forms/tests/test_pods.py
index ae695b8..9255884 100644
--- a/src/maasserver/forms/tests/test_pods.py
+++ b/src/maasserver/forms/tests/test_pods.py
@@ -466,13 +466,13 @@ class TestPodForm(MAASTransactionServerTestCase):
 
     def test_creates_lxd_pod_with_cert_expiration_supplied(self):
         pod_info = self.make_pod_info("lxd")
-        maas_cert = get_sample_cert("mypod", validity=timedelta(days=10))
+        maas_cert = get_sample_cert(validity=timedelta(days=5))
         pod_info["certificate"] = maas_cert.certificate_pem()
         pod_info["key"] = maas_cert.private_key_pem()
         form = PodForm(data=pod_info, request=self.request)
         self.assertTrue(form.is_valid(), form._errors)
         pod = form.save()
-        self.assertEqual(9, pod.created_with_cert_expiration_days)
+        self.assertEqual(4, pod.created_with_cert_expiration_days)
 
     def test_creates_lxd_pod_with_maas_generated_cert_supplied(self):
         pod_info = self.make_pod_info("lxd")
diff --git a/src/provisioningserver/testing/certificates.py b/src/provisioningserver/testing/certificates.py
index 374e132..fe71fd3 100644
--- a/src/provisioningserver/testing/certificates.py
+++ b/src/provisioningserver/testing/certificates.py
@@ -5,19 +5,17 @@ from fixtures import Fixture
 from provisioningserver.certificates import Certificate
 
 
-@lru_cache()
+@lru_cache(maxsize=5)
 def get_sample_cert(name: str = "maas", *args, **kwargs) -> Certificate:
     """Return a sample Certificate for tests."""
     return Certificate.generate(name, *args, **kwargs)
 
 
-@lru_cache()
-def get_sample_cert_with_cacerts(
-    name: str = "maas", ca_name: str = "CA", *args, **kwargs
-) -> Certificate:
+@lru_cache(maxsize=1)
+def get_sample_cert_with_cacerts() -> Certificate:
     """Return a sample Certificate with CA material for tests."""
-    cert = get_sample_cert(name, *args, **kwargs)
-    ca_cert = get_sample_cert(name=ca_name)
+    cert = get_sample_cert()
+    ca_cert = get_sample_cert(name="CA")
     return Certificate.from_pem(
         cert.private_key_pem(),
         cert.certificate_pem(),
diff --git a/src/provisioningserver/tests/test_certificates.py b/src/provisioningserver/tests/test_certificates.py
index e0335e0..444f0b0 100644
--- a/src/provisioningserver/tests/test_certificates.py
+++ b/src/provisioningserver/tests/test_certificates.py
@@ -20,7 +20,7 @@ from provisioningserver.testing.certificates import get_sample_cert
 class TestCertificate(MAASTestCase):
     def setUp(self):
         super().setUp()
-        self.sample_cert = get_sample_cert("maas")
+        self.sample_cert = get_sample_cert()
 
     def test_certificate(self):
         self.assertEqual(self.sample_cert.cn(), "maas")