Remove timer from FAST_REBOOT STATE_DB entry and use finalizer (#2621)

This should come along with sonic-buildimage PR (sonic-net/sonic-buildimage#13484) implementing fast-reboot finalizing logic in finalize-warmboot script and other submodules PRs utilizing the change.

This PR should come along with the following PRs as well:
sonic-net/sonic-swss-common#742
sonic-net/sonic-platform-daemons#335
sonic-net/sonic-sairedis#1196

This set of PRs solves the issue sonic-net/sonic-buildimage#13251

What I did
Remove the timer used to clear fast-reboot entry from state-db, instead it will be cleared by fast-reboot finalize function implemented inside finalize-warmboot script (which will be invoked since fast-reboot is using warm-reboot infrastructure).

As well instead of having "1" as the value for fast-reboot entry in state-db and deleting it when done it is now modified to set enable/disable according to the context.

As well all scripts reading this entry should be modified to the new value options.

How I did it
Removed the timer usage in the fast-reboot script and adding fast-reboot finalize logic to warm-reboot in the linked PR.
Use "enable/disable" instead of "1" as the entry value.

How to verify it
Run fast-reboot and check that the state-db entry for fast-reboot is being deleted after finalizing fast-reboot and not by an expiring timer.

scripts/db_migrator.py

@@ -45,7 +45,7 @@ def __init__(self, namespace, socket=None):
                      none-zero values.
               build: sequentially increase within a minor version domain.
         """
-        self.CURRENT_VERSION = 'version_4_0_0'
+        self.CURRENT_VERSION = 'version_4_0_1'
 
         self.TABLE_NAME      = 'VERSIONS'
         self.TABLE_KEY       = 'DATABASE'
@@ -850,9 +850,28 @@ def version_3_0_6(self):
     def version_4_0_0(self):
         """
         Version 4_0_0.
-        This is the latest version for master branch
         """
         log.log_info('Handling version_4_0_0')
+        # Update state-db fast-reboot entry to enable if set to enable fast-reboot finalizer when using upgrade with fast-reboot
+        # since upgrading from previous version FAST_REBOOT table will be deleted when the timer will expire.
+        # reading FAST_REBOOT table can't be done with stateDB.get as it uses hget behind the scenes and the table structure is
+        # not using hash and won't work.
+        # FAST_REBOOT table exists only if fast-reboot was triggered.
+        keys = self.stateDB.keys(self.stateDB.STATE_DB, "FAST_REBOOT")
+        if keys is not None:
+            enable_state = 'true'
+        else:
+            enable_state = 'false'
+        self.stateDB.set(self.stateDB.STATE_DB, 'FAST_RESTART_ENABLE_TABLE|system', 'enable', enable_state)
+        self.set_version('version_4_0_1')
+        return 'version_4_0_1'
+
+    def version_4_0_1(self):
+        """
+        Version 4_0_1.
+        This is the latest version for master branch
+        """
+        log.log_info('Handling version_4_0_1')
         return None
 
     def get_version(self):

scripts/fast-reboot

@@ -148,7 +148,7 @@ function clear_boot()
 
     #clear_fast_boot
     if [[ "$REBOOT_TYPE" = "fast-reboot" ]]; then
-        sonic-db-cli STATE_DB DEL "FAST_REBOOT|system" &>/dev/null || /bin/true
+        sonic-db-cli STATE_DB HSET "FAST_RESTART_ENABLE_TABLE|system" "enable" "false" &>/dev/null || /bin/true
     fi
 }
 
@@ -265,7 +265,7 @@ function backup_database()
                                           and not string.match(k, 'WARM_RESTART_ENABLE_TABLE|') \
                                           and not string.match(k, 'VXLAN_TUNNEL_TABLE|') \
                                           and not string.match(k, 'BUFFER_MAX_PARAM_TABLE|') \
-                                          and not string.match(k, 'FAST_REBOOT|') then
+                                          and not string.match(k, 'FAST_RESTART_ENABLE_TABLE|') then
                 redis.call('del', k)
             end
         end
@@ -532,7 +532,7 @@ case "$REBOOT_TYPE" in
         check_warm_restart_in_progress
         BOOT_TYPE_ARG=$REBOOT_TYPE
         trap clear_boot EXIT HUP INT QUIT TERM KILL ABRT ALRM
-        sonic-db-cli STATE_DB SET "FAST_REBOOT|system" "1" "EX" "210" &>/dev/null
+        sonic-db-cli STATE_DB HSET "FAST_RESTART_ENABLE_TABLE|system" "enable" "true" &>/dev/null
         config warm_restart enable system
         ;;
     "warm-reboot")

sonic-utilities-data/templates/service_mgmt.sh.j2

@@ -51,7 +51,8 @@ function check_warm_boot()
 
 function check_fast_boot()
 {
-    if [[ $($SONIC_DB_CLI STATE_DB GET "FAST_REBOOT|system") == "1" ]]; then
+    SYSTEM_FAST_REBOOT=`$SONIC_DB_CLI STATE_DB hget "FAST_RESTART_ENABLE_TABLE|system" enable`
+    if [[ x"${SYSTEM_FAST_REBOOT}" == x"true" ]]; then
         FAST_BOOT="true"
     else
         FAST_BOOT="false"

tests/db_migrator_input/state_db/fast_reboot_expected.json

@@ -0,0 +1,5 @@
+{
+    "FAST_RESTART_ENABLE_TABLE|system": {
+        "enable": "false"
+    }
+}

tests/db_migrator_input/state_db/fast_reboot_input.json

@@ -0,0 +1,2 @@
+{
+}

tests/db_migrator_test.py

@@ -451,6 +451,38 @@ def test_move_logger_tables_in_warm_upgrade(self):
         diff = DeepDiff(resulting_table, expected_table, ignore_order=True)
         assert not diff
 
+class TestFastRebootTableModification(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['STATE_DB'] = None
+
+    def mock_dedicated_state_db(self):
+        dbconnector.dedicated_dbs['STATE_DB'] = os.path.join(mock_db_path, 'state_db')
+
+    def test_rename_fast_reboot_table_check_enable(self):
+        device_info.get_sonic_version_info = get_sonic_version_info_mlnx
+        dbconnector.dedicated_dbs['STATE_DB'] = os.path.join(mock_db_path, 'state_db', 'fast_reboot_input')
+        dbconnector.dedicated_dbs['CONFIG_DB'] = os.path.join(mock_db_path, 'config_db', 'empty-config-input')
+
+        import db_migrator
+        dbmgtr = db_migrator.DBMigrator(None)
+        dbmgtr.migrate()
+
+        dbconnector.dedicated_dbs['STATE_DB'] = os.path.join(mock_db_path, 'state_db', 'fast_reboot_expected')
+        expected_db = SonicV2Connector(host='127.0.0.1')
+        expected_db.connect(expected_db.STATE_DB)
+
+        resulting_table = dbmgtr.stateDB.get_all(dbmgtr.stateDB.STATE_DB, 'FAST_RESTART_ENABLE_TABLE|system')
+        expected_table = expected_db.get_all(expected_db.STATE_DB, 'FAST_RESTART_ENABLE_TABLE|system')
+
+        diff = DeepDiff(resulting_table, expected_table, ignore_order=True)
+        assert not diff
+
 class TestWarmUpgrade_to_2_0_2(object):
     @classmethod
     def setup_class(cls):