[db_migrator] Migrate DNS configuratuion (sonic-net#2893)

What I did
sonic-net/sonic-buildimage#14549
This PR has introduced DNS configuration to CONFIG_DB, we need to migrate original CONFIG_DB to support DNS configuration during upgrading SONiC.

How I did it
If there's no DNS_NAMESERVER table in CONFIG_DB, read DNS_NAMESERVER table from minigraph and update CONFIG_DB.

How to verify it
Run unit test for db migrator.

scripts/db_migrator.py

@@ -47,8 +47,7 @@ def __init__(self, namespace, socket=None):
  none-zero values.
  build: sequentially increase within a minor version domain.
  """
-
- self.CURRENT_VERSION = 'version_4_0_4'
+ self.CURRENT_VERSION = 'version_4_0_5'
 
  self.TABLE_NAME = 'VERSIONS'
  self.TABLE_KEY = 'DATABASE'
@@ -638,6 +637,18 @@ def migrate_route_table(self):
  if 'protocol' not in route_attr:
  self.appDB.set(self.appDB.APPL_DB, route_key, 'protocol', '')
 
+ def migrate_dns_nameserver(self):
+ """
+ Handle DNS_NAMESERVER table migration. Migrations handled:
+ If there's no DNS_NAMESERVER in config_DB, load DNS_NAMESERVER from minigraph
+ """
+ if not self.minigraph_data or 'DNS_NAMESERVER' not in self.minigraph_data:
+ return
+ dns_table = self.configDB.get_table('DNS_NAMESERVER')
+ if not dns_table:
+ for addr, config in self.minigraph_data['DNS_NAMESERVER'].items():
+ self.configDB.set_entry('DNS_NAMESERVER', addr, config)
+
  def migrate_routing_config_mode(self):
  # DEVICE_METADATA - synchronous_mode entry
  if not self.minigraph_data or 'DEVICE_METADATA' not in self.minigraph_data:
@@ -1042,6 +1053,17 @@ def version_4_0_3(self):
  """
  log.log_info('Handling version_4_0_3')
 
+ # Updating DNS nameserver
+ self.migrate_dns_nameserver()
+ self.set_version('version_4_0_4')
+ return 'version_4_0_4'
+
+ def version_4_0_4(self):
+ """
+ Version 4_0_4.
+ """
+ log.log_info('Handling version_4_0_4')
+
  sflow_tbl = self.configDB.get_table('SFLOW')
  for k, v in sflow_tbl.items():
  if 'sample_direction' not in v:
@@ -1056,14 +1078,16 @@ def version_4_0_3(self):
 
  self.migrate_sflow_table()
 
- self.set_version('version_4_0_4')
- return 'version_4_0_4'
+ self.set_version('version_4_0_5')
+ return 'version_4_0_5'
 
- def version_4_0_4(self):
+ def version_4_0_5(self):
  """
- Current latest version. Nothing to do here.
+ Version 4_0_5.
+ This is the latest version for master branch
  """
- log.log_info('Handling version_4_0_4')
+ log.log_info('Handling version_4_0_5')
+
  return None
 
  def get_version(self):

tests/db_migrator_input/config_db/dns-nameserver-expected.json

@@ -0,0 +1,11 @@
+{
+ "DNS_NAMESERVER|1.1.1.1": {
+ "state": "enabled"
+ },
+ "DNS_NAMESERVER|2001:1001:110:1001::1": {
+ "state": "enabled"
+ },
+ "VERSIONS|DATABASE": {
+ "VERSION": "version_4_0_4"
+ }
+}

tests/db_migrator_input/config_db/dns-nameserver-input.json

@@ -0,0 +1,5 @@
+{
+ "VERSIONS|DATABASE": {
+ "VERSION": "version_4_0_3"
+ }
+}

tests/db_migrator_test.py

@@ -294,6 +294,37 @@ def test_lacp_key_migrator(self):
  assert dbmgtr.configDB.get_table('PORTCHANNEL') == expected_db.cfgdb.get_table('PORTCHANNEL')
  assert dbmgtr.configDB.get_table('VERSIONS') == expected_db.cfgdb.get_table('VERSIONS')
 
+class TestDnsNameserverMigrator(object):
+ @classmethod
+ def setup_class(cls):
+ os.environ['UTILITIES_UNIT_TESTING'] = "2"
+
+ @classmethod
+ def teardown_class(cls):
+ os.environ['UTILITIES_UNIT_TESTING'] = "0"
+ dbconnector.dedicated_dbs['CONFIG_DB'] = None
+
+ def test_dns_nameserver_migrator(self):
+ dbconnector.dedicated_dbs['CONFIG_DB'] = os.path.join(mock_db_path, 'config_db', 'dns-nameserver-input')
+ import db_migrator
+ dbmgtr = db_migrator.DBMigrator(None)
+ # Set minigraph_data to DNS_NAMESERVERS
+ dbmgtr.minigraph_data = {
+ 'DNS_NAMESERVER': {
+ '1.1.1.1': {},
+ '2001:1001:110:1001::1': {}
+ }
+ }
+ dbmgtr.migrate()
+ dbconnector.dedicated_dbs['CONFIG_DB'] = os.path.join(mock_db_path, 'config_db', 'dns-nameserver-expected')
+ expected_db = Db()
+ advance_version_for_expected_database(dbmgtr.configDB, expected_db.cfgdb, 'version_4_0_4')
+ resulting_keys = dbmgtr.configDB.keys(dbmgtr.configDB.CONFIG_DB, 'DNS_NAMESERVER*')
+ expected_keys = expected_db.cfgdb.keys(expected_db.cfgdb.CONFIG_DB, 'DNS_NAMESERVER*')
+
+ diff = DeepDiff(resulting_keys, expected_keys, ignore_order=True)
+ assert not diff
+
 class TestQosDBFieldValueReferenceRemoveMigrator(object):
  @classmethod
  def setup_class(cls):
@@ -680,6 +711,7 @@ def test_fast_reboot_upgrade_to_4_0_3(self):
  dbmgtr = db_migrator.DBMigrator(None)
  dbmgtr.migrate()
  expected_db = self.mock_dedicated_config_db(db_after_migrate)
+ advance_version_for_expected_database(dbmgtr.configDB, expected_db.cfgdb, 'version_4_0_3')
  assert not self.check_config_db(dbmgtr.configDB, expected_db.cfgdb)
  if dbmgtr.CURRENT_VERSION == 'version_4_0_3':
  assert dbmgtr.CURRENT_VERSION == expected_db.cfgdb.get_entry('VERSIONS', 'DATABASE')['VERSION']