samba-tool: add dns cleanup cmd

1. Add new command to cleanup dns records for a dns host name
2. Add test to verify the command is working

Signed-off-by: Joe Guo <joeg@catalyst.net.nz>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>

python/samba/netcmd/dns.py

@@ -15,6 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
+import logging
 
 import samba.getopt as options
 from samba import WERRORError
@@ -26,6 +27,10 @@ from socket import AF_INET
 from socket import AF_INET6
 import shlex
 
+from samba import remove_dc
+from samba.samdb import SamDB
+from samba.auth import system_session
+
 from samba.netcmd import (
     Command,
     CommandError,
@@ -1068,6 +1073,47 @@ class cmd_delete_record(Command):
         self.outf.write('Record deleted successfully\n')
 
 
+class cmd_cleanup_record(Command):
+    """Cleanup DNS records for a DNS host.
+
+    example:
+
+        samba-tool dns cleanup dc1 dc1.samdom.test.site -U USER%PASSWORD
+
+    NOTE: This command doesn't delete the DNS records,
+    it only mark the `dNSTombstoned` attr as `TRUE`.
+    """
+
+    synopsis = '%prog <server> <dnshostname>'
+
+    takes_args = ['server', 'dnshostname']
+
+    takes_optiongroups = {
+        "sambaopts": options.SambaOptions,
+        "versionopts": options.VersionOptions,
+        "credopts": options.CredentialsOptions,
+    }
+
+    def run(self, server, dnshostname, sambaopts=None, credopts=None,
+            versionopts=None, verbose=False, quiet=False):
+        lp = sambaopts.get_loadparm()
+        creds = credopts.get_credentials(lp)
+
+        logger = self.get_logger()
+        if verbose:
+            logger.setLevel(logging.DEBUG)
+        elif quiet:
+            logger.setLevel(logging.WARNING)
+        else:
+            logger.setLevel(logging.INFO)
+
+        samdb = SamDB(url="ldap://%s" % server,
+                      session_info=system_session(),
+                      credentials=creds, lp=lp)
+
+        remove_dc.remove_dns_references(samdb, logger, dnshostname)
+
+
 class cmd_dns(SuperCommand):
     """Domain Name Service (DNS) management."""
 
@@ -1082,3 +1128,4 @@ class cmd_dns(SuperCommand):
     subcommands['add'] = cmd_add_record()
     subcommands['update'] = cmd_update_record()
     subcommands['delete'] = cmd_delete_record()
+    subcommands['cleanup'] = cmd_cleanup_record()

python/samba/tests/samba_tool/dnscmd.py

@@ -660,6 +660,109 @@ class DnsCmdTestCase(SambaToolCmdTest):
                                           "A", self.testip, self.creds_string)
         self.assertCmdFail(result)
 
+    def test_cleanup_record(self):
+        """
+        Test dns cleanup command is working fine.
+        """
+
+        # add a A record
+        self.runsubcmd("dns", "add", os.environ["SERVER"], self.zone,
+                       'testa', "A", self.testip, self.creds_string)
+
+        # the above A record points to this host
+        dnshostname = '{}.{}'.format('testa', self.zone.lower())
+
+        # add a CNAME record points to above host
+        self.runsubcmd("dns", "add", os.environ["SERVER"], self.zone,
+                       'testcname', "CNAME", dnshostname, self.creds_string)
+
+        # add a NS record
+        self.runsubcmd("dns", "add", os.environ["SERVER"], self.zone,
+                       'testns', "NS", dnshostname, self.creds_string)
+
+        # add a PTR record points to above host
+        self.runsubcmd("dns", "add", os.environ["SERVER"], self.zone,
+                       'testptr', "PTR", dnshostname, self.creds_string)
+
+        # add a SRV record points to above host
+        srv_record = "{} 65530 65530 65530".format(dnshostname)
+        self.runsubcmd("dns", "add", os.environ["SERVER"], self.zone,
+                       'testsrv', "SRV", srv_record, self.creds_string)
+
+        # cleanup record for this dns host
+        self.runsubcmd("dns", "cleanup", os.environ["SERVER"],
+                       dnshostname, self.creds_string)
+
+        # all records should be marked as dNSTombstoned
+        for record_name in ['testa', 'testcname', 'testns', 'testptr', 'testsrv']:
+
+            records = self.samdb.search(
+                base="DC=DomainDnsZones,{}".format(self.samdb.get_default_basedn()),
+                scope=ldb.SCOPE_SUBTREE,
+                expression="(&(objectClass=dnsNode)(name={}))".format(record_name),
+                attrs=["dNSTombstoned"])
+
+            self.assertEqual(len(records), 1)
+            for record in records:
+                self.assertEqual(str(record['dNSTombstoned']), 'TRUE')
+
+    def test_cleanup_multi_srv_record(self):
+        """
+        Test dns cleanup command for multi-valued SRV record.
+
+        Steps:
+        - Add 2 A records host1 and host2
+        - Add a SRV record srv1 and points to both host1 and host2
+        - Run cleanup command for host1
+        - Check records for srv1, data for host1 should be gone and host2 is kept.
+        """
+
+        hosts = ['host1', 'host2']  # A record names
+        srv_name = 'srv1'
+
+        # add A records
+        for host in hosts:
+            self.runsubcmd("dns", "add", os.environ["SERVER"], self.zone,
+                           host, "A", self.testip, self.creds_string)
+
+            # the above A record points to this host
+            dnshostname = '{}.{}'.format(host, self.zone.lower())
+
+            # add a SRV record points to above host
+            srv_record = "{} 65530 65530 65530".format(dnshostname)
+            self.runsubcmd("dns", "add", os.environ["SERVER"], self.zone,
+                           srv_name, "SRV", srv_record, self.creds_string)
+
+        records = self.samdb.search(
+            base="DC=DomainDnsZones,{}".format(self.samdb.get_default_basedn()),
+            scope=ldb.SCOPE_SUBTREE,
+            expression="(&(objectClass=dnsNode)(name={}))".format(srv_name),
+            attrs=['dnsRecord'])
+        # should have 2 records here
+        self.assertEqual(len(records[0]['dnsRecord']), 2)
+
+        # cleanup record for dns host1
+        dnshostname1 = 'host1.{}'.format(self.zone.lower())
+        self.runsubcmd("dns", "cleanup", os.environ["SERVER"],
+                       dnshostname1, self.creds_string)
+
+        records = self.samdb.search(
+            base="DC=DomainDnsZones,{}".format(self.samdb.get_default_basedn()),
+            scope=ldb.SCOPE_SUBTREE,
+            expression="(&(objectClass=dnsNode)(name={}))".format(srv_name),
+            attrs=['dnsRecord'])
+
+        # dnsRecord for host1 should be deleted
+        self.assertEqual(len(records[0]['dnsRecord']), 1)
+
+        # unpack data
+        dns_record_bin = records[0]['dnsRecord'][0]
+        dns_record_obj = ndr_unpack(dnsp.DnssrvRpcRecord, dns_record_bin)
+
+        # dnsRecord for host2 is still there and is the only one
+        dnshostname2 = 'host2.{}'.format(self.zone.lower())
+        self.assertEqual(dns_record_obj.data.nameTarget, dnshostname2)
+
     def test_dns_wildcards(self):
         """
         Ensure that DNS wild card entries can be added deleted and queried