Merge ~cgrabowski/maas:clean_old_zonefiles_on_dns_setup into maas:master

[Christian Grabowski]

clean old zonefiles when setting up the zonefile dir

[MAAS Lander (maas-lander)]

UNIT TESTS
-b clean_old_zonefiles_on_dns_setup lp:~cgrabowski/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED
LOG: http://maas-ci.internal:8080/job/maas-tester/1398/consoleText
COMMIT: 4ee48ce858d635759191064afad7490335f70466

review: Needs Fixing

[Alexsander de Souza (alexsander-souza)]

+1

review: Approve

[MAAS Lander (maas-lander)]

UNIT TESTS
-b clean_old_zonefiles_on_dns_setup lp:~cgrabowski/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED
LOG: http://maas-ci.internal:8080/job/maas-tester/1399/consoleText
COMMIT: d2571796f3c192aa2bb544b6efdea58659a87781

review: Needs Fixing

[Christian Grabowski (cgrabowski)]

jenkins: !test

[MAAS Lander (maas-lander)]

UNIT TESTS
-b clean_old_zonefiles_on_dns_setup lp:~cgrabowski/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED
LOG: http://maas-ci.internal:8080/job/maas-tester/1402/consoleText
COMMIT: d2571796f3c192aa2bb544b6efdea58659a87781

review: Needs Fixing

[MAAS Lander (maas-lander)]

UNIT TESTS
-b clean_old_zonefiles_on_dns_setup lp:~cgrabowski/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: f85d69615c9bd786ebaa641f82d4cd102ae9b5dd

review: Approve

[MAAS Lander (maas-lander)]

LANDING
-b clean_old_zonefiles_on_dns_setup lp:~cgrabowski/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci.internal:8080/job/maas-tester/1405/consoleText

diff --git a/src/maasserver/dns/tests/test_config.py b/src/maasserver/dns/tests/test_config.py
index 913c96e..9a2835d 100644
--- a/src/maasserver/dns/tests/test_config.py
+++ b/src/maasserver/dns/tests/test_config.py
@@ -133,7 +133,7 @@ class TestDNSServer(MAASServerTestCase):
         patch_dns_config_path(self, self.bind.config.homedir)
         # Use a random port for rndc.
         patch_dns_rndc_port(self, allocate_ports("localhost")[0])
-        patch_zone_file_config_path(self, config_dir=self.bind.config.homedir)
+        patch_zone_file_config_path(self, config_dir=self.bind.config.zonedir)
         # This simulates what should happen when the package is
         # installed:
         # Create MAAS-specific DNS configuration files.
diff --git a/src/provisioningserver/dns/commands/tests/test_setup_dns.py b/src/provisioningserver/dns/commands/tests/test_setup_dns.py
index e720cff..132dc5e 100644
--- a/src/provisioningserver/dns/commands/tests/test_setup_dns.py
+++ b/src/provisioningserver/dns/commands/tests/test_setup_dns.py
@@ -46,8 +46,9 @@ class TestSetupCommand(MAASTestCase):
 
     def test_does_not_overwrite_config(self):
         dns_conf_dir = self.make_dir()
+        zone_file_dir = self.make_dir()
         patch_dns_config_path(self, dns_conf_dir)
-        patch_zone_file_config_path(self, dns_conf_dir)
+        patch_zone_file_config_path(self, zone_file_dir)
         random_content = factory.make_string()
         factory.make_file(
             location=dns_conf_dir,
diff --git a/src/provisioningserver/dns/config.py b/src/provisioningserver/dns/config.py
index 5673b4a..199fb76 100644
--- a/src/provisioningserver/dns/config.py
+++ b/src/provisioningserver/dns/config.py
@@ -239,6 +239,13 @@ def set_up_nsupdate_key():
     atomic_write(tsig, get_nsupdate_key_path(), overwrite=True, mode=0o644)
 
 
+def clean_old_zone_files():
+    p = get_zone_file_config_dir()
+    files = os.listdir(p)
+    for f in files:
+        os.remove(os.path.join(p, f))
+
+
 def set_up_zone_file_dir():
     p = get_zone_file_config_dir()
     if not os.path.exists(p):
@@ -252,6 +259,8 @@ def set_up_zone_file_dir():
 
         os.chown(p, uid, gid)
         os.chmod(p, 0o775)
+    else:
+        clean_old_zone_files()
 
 
 def set_up_rndc():
diff --git a/src/provisioningserver/dns/tests/test_config.py b/src/provisioningserver/dns/tests/test_config.py
index 1e02498..ca6f037 100644
--- a/src/provisioningserver/dns/tests/test_config.py
+++ b/src/provisioningserver/dns/tests/test_config.py
@@ -35,6 +35,7 @@ from maastesting.fakemethod import FakeMethod
 from maastesting.testcase import MAASTestCase
 from provisioningserver.dns import config
 from provisioningserver.dns.config import (
+    clean_old_zone_files,
     compose_config_path,
     DEFAULT_CONTROLS,
     DNSConfig,
@@ -58,6 +59,7 @@ from provisioningserver.dns.config import (
 from provisioningserver.dns.testing import (
     patch_dns_config_path,
     patch_dns_default_controls,
+    patch_zone_file_config_path,
 )
 from provisioningserver.dns.zoneconfig import (
     DNSForwardZoneConfig,
@@ -290,6 +292,21 @@ class TestRNDCUtilities(MAASTestCase):
         )
         self.assertThat(target_file, FileExists())
 
+    def test_clean_old_zone_files(self):
+        zone_file_dir = patch_zone_file_config_path(self)
+
+        zonefiles = [
+            os.path.join(zone_file_dir, f"zonefile{i}")
+            for i, _ in enumerate(range(2))
+        ]
+        for zonefile in zonefiles:
+            with open(zonefile, "w+"):
+                pass
+
+        clean_old_zone_files()
+        for zonefile in zonefiles:
+            self.assertRaises(FileNotFoundError, os.stat, zonefile)
+
     def test_rndc_config_includes_default_controls(self):
         dns_conf_dir = patch_dns_config_path(self)
         patch_dns_default_controls(self, enable=True)
diff --git a/src/provisioningserver/testing/bindfixture.py b/src/provisioningserver/testing/bindfixture.py
index 448fad8..714ff04 100644
--- a/src/provisioningserver/testing/bindfixture.py
+++ b/src/provisioningserver/testing/bindfixture.py
@@ -134,6 +134,7 @@ class BINDServerResources(fixtures.Fixture):
         port=None,
         rndc_port=None,
         homedir=None,
+        zonedir=None,
         log_file=None,
         include_in_options=None,
     ):
@@ -142,6 +143,7 @@ class BINDServerResources(fixtures.Fixture):
             port=port,
             rndc_port=rndc_port,
             homedir=homedir,
+            zonedir=zonedir,
             log_file=log_file,
             include_in_options=include_in_options,
         )
@@ -209,6 +211,8 @@ class BINDServerResources(fixtures.Fixture):
             [self.rndc_port] = allocate_ports("localhost")
         if self.homedir is None:
             self.homedir = self.useFixture(TempDirectory()).path
+        if self.zonedir is None:
+            self.zonedir = self.useFixture(TempDirectory()).path
         if self.log_file is None:
             self.log_file = os.path.join(self.homedir, "named.log")
         self.named_file = os.path.join(