[bgpcfgd] Add bgpcfgd support to advertise routes (#9197) (#9697)

Why I did it
Cherry pick changes in #9197 to 202012 branch
Add bgpcfgd support to advertise routes.

How I did it
Make bgpcfgd subscribe to the ADVERTISE_NETWORK table in STATE_DB and configure route advertisement accordingly.

How to verify it
Added unit tests in bgpcfgd and verify on KVM about route advertisement.

Author: shi-su

files/scripts/swss.sh

@@ -147,7 +147,7 @@ start() {
         $SONIC_DB_CLI COUNTERS_DB FLUSHDB
         $SONIC_DB_CLI FLEX_COUNTER_DB FLUSHDB
         $SONIC_DB_CLI RESTAPI_DB FLUSHDB
-        clean_up_tables STATE_DB "'PORT_TABLE*', 'MGMT_PORT_TABLE*', 'VLAN_TABLE*', 'VLAN_MEMBER_TABLE*', 'LAG_TABLE*', 'LAG_MEMBER_TABLE*', 'INTERFACE_TABLE*', 'MIRROR_SESSION*', 'VRF_TABLE*', 'FDB_TABLE*', 'FG_ROUTE_TABLE*', 'BUFFER_POOL*', 'BUFFER_PROFILE*', 'MUX_CABLE_TABLE*'"
+        clean_up_tables STATE_DB "'PORT_TABLE*', 'MGMT_PORT_TABLE*', 'VLAN_TABLE*', 'VLAN_MEMBER_TABLE*', 'LAG_TABLE*', 'LAG_MEMBER_TABLE*', 'INTERFACE_TABLE*', 'MIRROR_SESSION*', 'VRF_TABLE*', 'FDB_TABLE*', 'FG_ROUTE_TABLE*', 'BUFFER_POOL*', 'BUFFER_PROFILE*', 'MUX_CABLE_TABLE*', 'ADVERTISE_NETWORK_TABLE*'"
     fi
 
     # start service docker

src/sonic-bgpcfgd/bgpcfgd/main.py

@@ -9,6 +9,7 @@
 from .config import ConfigMgr
 from .directory import Directory
 from .log import log_notice, log_crit
+from .managers_advertise_rt import AdvertiseRouteMgr
 from .managers_allow_list import BGPAllowListMgr
 from .managers_bbr import BBRMgr
 from .managers_bgp import BGPPeerMgrBase
@@ -57,6 +58,8 @@ def do_work():
         BBRMgr(common_objs, "CONFIG_DB", "BGP_BBR"),
         # Static Route Managers
         StaticRouteMgr(common_objs, "CONFIG_DB", "STATIC_ROUTE"),
+        # Route Advertisement Managers
+        AdvertiseRouteMgr(common_objs, "STATE_DB", swsscommon.STATE_ADVERTISE_NETWORK_TABLE_NAME),
     ]
     runner = Runner(common_objs['cfg_mgr'])
     for mgr in managers:

src/sonic-bgpcfgd/bgpcfgd/managers_advertise_rt.py

@@ -0,0 +1,108 @@
+from .manager import Manager
+from .template import TemplateFabric
+from swsscommon import swsscommon
+
+
+class AdvertiseRouteMgr(Manager):
+    """ This class Advertises routes when ADVERTISE_NETWORK_TABLE in STATE_DB is updated """
+    def __init__(self, common_objs, db, table):
+        """
+        Initialize the object
+        :param common_objs: common object dictionary
+        :param db: name of the db
+        :param table: name of the table in the db
+        """
+        super(AdvertiseRouteMgr, self).__init__(
+            common_objs,
+            [],
+            db,
+            table,
+        )
+        
+        self.directory.subscribe([("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME, "localhost/bgp_asn"),], self.on_bgp_asn_change)
+        self.advertised_routes = dict()
+
+
+    OP_DELETE = 'DELETE'
+    OP_ADD = 'ADD'
+
+
+    def set_handler(self, key, data):
+        vrf, ip_prefix = self.split_key(key)
+        self.add_route_advertisement(vrf, ip_prefix)
+
+        return True
+
+
+    def del_handler(self, key):
+        vrf, ip_prefix = self.split_key(key)
+        self.remove_route_advertisement(vrf, ip_prefix)
+
+
+    def add_route_advertisement(self, vrf, ip_prefix):
+        if self.directory.path_exist("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME, "localhost/bgp_asn"):
+            if not self.advertised_routes.get(vrf, set()):
+                self.bgp_network_import_check_commands(vrf, self.OP_ADD)
+            self.advertise_route_commands(ip_prefix, vrf, self.OP_ADD)
+
+        self.advertised_routes.setdefault(vrf, set()).add(ip_prefix)
+
+
+    def remove_route_advertisement(self, vrf, ip_prefix):
+        self.advertised_routes.setdefault(vrf, set()).discard(ip_prefix)
+        if not self.advertised_routes.get(vrf, set()):
+            self.advertised_routes.pop(vrf, None)
+
+        if self.directory.path_exist("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME, "localhost/bgp_asn"):
+            if not self.advertised_routes.get(vrf, set()):
+                self.bgp_network_import_check_commands(vrf, self.OP_DELETE)
+            self.advertise_route_commands(ip_prefix, vrf, self.OP_DELETE)
+
+
+    def advertise_route_commands(self, ip_prefix, vrf, op):
+        is_ipv6 = TemplateFabric.is_ipv6(ip_prefix)
+        bgp_asn = self.directory.get_slot("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME)["localhost"]["bgp_asn"]
+
+        cmd_list = []
+        if vrf == 'default':
+            cmd_list.append("router bgp %s" % bgp_asn)
+        else:
+            cmd_list.append("router bgp %s vrf %s" % (bgp_asn, vrf))
+
+        cmd_list.append(" address-family %s unicast" % ("ipv6" if is_ipv6 else "ipv4"))
+        cmd_list.append("  %snetwork %s" % ('no ' if op == self.OP_DELETE else '', ip_prefix))
+
+        self.cfg_mgr.push_list(cmd_list)
+
+
+    def bgp_network_import_check_commands(self, vrf, op):
+        bgp_asn = self.directory.get_slot("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME)["localhost"]["bgp_asn"]
+        cmd_list = []
+        if vrf == 'default':
+            cmd_list.append("router bgp %s" % bgp_asn)
+        else:
+            cmd_list.append("router bgp %s vrf %s" % (bgp_asn, vrf))
+        cmd_list.append(" %sbgp network import-check" % ('' if op == self.OP_DELETE else 'no '))
+
+        self.cfg_mgr.push_list(cmd_list)
+
+
+    def on_bgp_asn_change(self):
+        if self.directory.path_exist("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME, "localhost/bgp_asn"):
+            for vrf, ip_prefixes in self.advertised_routes.items():
+                self.bgp_network_import_check_commands(vrf, self.OP_ADD)
+                for ip_prefix in ip_prefixes:
+                    self.add_route_advertisement(vrf, ip_prefix)
+
+
+    @staticmethod
+    def split_key(key):
+        """
+        Split key into vrf name and prefix.
+        :param key: key to split
+        :return: vrf name extracted from the key, ip prefix extracted from the key
+        """
+        if '|' not in key:
+            return 'default', key
+        else:
+            return tuple(key.split('|', 1))

src/sonic-bgpcfgd/tests/test_advertise_rt.py

@@ -0,0 +1,185 @@
+from unittest.mock import MagicMock, patch
+
+from bgpcfgd.directory import Directory
+from bgpcfgd.template import TemplateFabric
+from bgpcfgd.managers_advertise_rt import AdvertiseRouteMgr
+from swsscommon import swsscommon
+
+def constructor(skip_bgp_asn=False):
+    cfg_mgr = MagicMock()
+
+    common_objs = {
+        'directory': Directory(),
+        'cfg_mgr':   cfg_mgr,
+        'tf':        TemplateFabric(),
+        'constants': {},
+    }
+
+    mgr = AdvertiseRouteMgr(common_objs, "STATE_DB", swsscommon.STATE_ADVERTISE_NETWORK_TABLE_NAME)
+    if not skip_bgp_asn:
+        mgr.directory.put("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME, "localhost", {"bgp_asn": "65100"})
+    assert len(mgr.advertised_routes) == 0
+
+    return mgr
+
+def set_del_test(mgr, op, args, expected_ret, expected_cmds):
+    set_del_test.push_list_called = False
+    def push_list(cmds):
+        set_del_test.push_list_called = True
+        assert cmds in expected_cmds
+        return True
+    mgr.cfg_mgr.push_list = push_list
+
+    if op == "SET":
+        ret = mgr.set_handler(*args)
+        assert ret == expected_ret
+    elif op == "DEL":
+        mgr.del_handler(*args)
+    else:
+        assert False, "Wrong operation"
+
+    if expected_cmds:
+        assert set_del_test.push_list_called, "cfg_mgr.push_list wasn't called"
+    else:
+        assert not set_del_test.push_list_called, "cfg_mgr.push_list was called"
+
+def test_set_del():
+    mgr = constructor()
+    set_del_test(
+        mgr,
+        "SET",
+        ("10.1.0.0/24", {}),
+        True,
+        [
+            ["router bgp 65100",
+             " no bgp network import-check"],
+            ["router bgp 65100",
+             " address-family ipv4 unicast",
+             "  network 10.1.0.0/24"]
+        ]
+    )
+
+    set_del_test(
+        mgr,
+        "SET",
+        ("fc00:10::/64", {}),
+        True,
+        [
+            ["router bgp 65100",
+             " address-family ipv6 unicast",
+             "  network fc00:10::/64"]
+        ]
+    )
+
+    set_del_test(
+        mgr,
+        "DEL",
+        ("10.1.0.0/24",),
+        True,
+        [
+            ["router bgp 65100",
+             " address-family ipv4 unicast",
+             "  no network 10.1.0.0/24"]
+        ]
+    )
+
+    set_del_test(
+        mgr,
+        "DEL",
+        ("fc00:10::/64",),
+        True,
+        [
+            ["router bgp 65100",
+             " bgp network import-check"],
+            ["router bgp 65100",
+             " address-family ipv6 unicast",
+             "  no network fc00:10::/64"]
+        ]
+    )
+
+
+def test_set_del_vrf():
+    mgr = constructor()
+    set_del_test(
+        mgr,
+        "SET",
+        ("vrfRED|10.2.0.0/24", {}),
+        True,
+        [
+            ["router bgp 65100 vrf vrfRED",
+             " no bgp network import-check"],
+            ["router bgp 65100 vrf vrfRED",
+             " address-family ipv4 unicast",
+             "  network 10.2.0.0/24"]
+        ]
+    )
+
+    set_del_test(
+        mgr,
+        "SET",
+        ("vrfRED|fc00:20::/64", {}),
+        True,
+        [
+            ["router bgp 65100 vrf vrfRED",
+             " address-family ipv6 unicast",
+             "  network fc00:20::/64"]
+        ]
+    )
+
+    set_del_test(
+        mgr,
+        "DEL",
+        ("vrfRED|10.2.0.0/24",),
+        True,
+        [
+            ["router bgp 65100 vrf vrfRED",
+             " address-family ipv4 unicast",
+             "  no network 10.2.0.0/24"]
+        ]
+    )
+
+    set_del_test(
+        mgr,
+        "DEL",
+        ("vrfRED|fc00:20::/64",),
+        True,
+        [
+            ["router bgp 65100 vrf vrfRED",
+             " bgp network import-check"],
+            ["router bgp 65100 vrf vrfRED",
+             " address-family ipv6 unicast",
+             "  no network fc00:20::/64"]
+        ]
+    )
+
+
+def test_set_del_bgp_asn_change():
+    mgr = constructor(skip_bgp_asn=True)
+    set_del_test(
+        mgr,
+        "SET",
+        ("vrfRED|10.3.0.0/24", {}),
+        True,
+        []
+    )
+
+
+    test_set_del_bgp_asn_change.push_list_called = False
+    expected_cmds = [
+        ["router bgp 65100 vrf vrfRED",
+         " no bgp network import-check"],
+        ["router bgp 65100 vrf vrfRED",
+         " address-family ipv4 unicast",
+         "  network 10.3.0.0/24"]
+    ]
+    def push_list(cmds):
+        test_set_del_bgp_asn_change.push_list_called = True
+        assert cmds in expected_cmds
+        return True
+
+    mgr.cfg_mgr.push_list = push_list
+    assert not test_set_del_bgp_asn_change.push_list_called
+
+    mgr.directory.put("CONFIG_DB", swsscommon.CFG_DEVICE_METADATA_TABLE_NAME, "localhost", {"bgp_asn": "65100"})
+
+    assert test_set_del_bgp_asn_change.push_list_called