Revert "[config reload]: On dual ToR systems, cache ARP and FDB table… (

sonic-net#2460)

…s (sonic-net#1465)"

- This reverts commit 10de91d.
- Also removes '--disable-arp-cache' option from config reload tests that was added in sonic-net#2325

Signed-off-by: Lawrence Lee <lawlee@microsoft.com>

config/main.py

@@ -926,39 +926,6 @@ def update_sonic_environment():
             display_cmd=True
         )
 
-def cache_arp_entries():
-    success = True
-    cache_dir = '/host/config-reload'
-    click.echo('Caching ARP table to {}'.format(cache_dir))
-
-    if not os.path.exists(cache_dir):
-        os.mkdir(cache_dir)
-
-    arp_cache_cmd = '/usr/local/bin/fast-reboot-dump.py -t {}'.format(cache_dir)
-    cache_proc = subprocess.Popen(arp_cache_cmd, shell=True, text=True, stdout=subprocess.PIPE)
-    _, cache_err = cache_proc.communicate()
-    if cache_err:
-        click.echo("Could not cache ARP and FDB info prior to reloading")
-        success = False
-
-    if not cache_err:
-        fdb_cache_file = os.path.join(cache_dir, 'fdb.json')
-        arp_cache_file = os.path.join(cache_dir, 'arp.json')
-        fdb_filter_cmd = '/usr/local/bin/filter_fdb_entries -f {} -a {} -c /etc/sonic/config_db.json'.format(fdb_cache_file, arp_cache_file)
-        filter_proc = subprocess.Popen(fdb_filter_cmd, shell=True, text=True, stdout=subprocess.PIPE)
-        _, filter_err = filter_proc.communicate()
-        if filter_err:
-            click.echo("Could not filter FDB entries prior to reloading")
-            success = False
-
-    # If we are able to successfully cache ARP table info, signal SWSS to restore from our cache
-    # by creating /host/config-reload/needs-restore
-    if success:
-        restore_flag_file = os.path.join(cache_dir, 'needs-restore')
-        open(restore_flag_file, 'w').close()
-    return success
-
-
 def validate_ipv4_address(ctx, param, ip_addr):
     """Helper function to validate ipv4 address
     """
@@ -1169,10 +1136,9 @@ def load(filename, yes):
 @click.option('-y', '--yes', is_flag=True)
 @click.option('-l', '--load-sysinfo', is_flag=True, help='load system default information (mac, portmap etc) first.')
 @click.option('-n', '--no_service_restart', default=False, is_flag=True, help='Do not restart docker services')
-@click.option('-d', '--disable_arp_cache', default=False, is_flag=True, help='Do not cache ARP table before reloading (applies to dual ToR systems only)')
 @click.argument('filename', required=False)
 @clicommon.pass_db
-def reload(db, filename, yes, load_sysinfo, no_service_restart, disable_arp_cache):
+def reload(db, filename, yes, load_sysinfo, no_service_restart):
     """Clear current configuration and import a previous saved config DB dump file.
        <filename> : Names of configuration file(s) to load, separated by comma with no spaces in between
     """
@@ -1216,13 +1182,6 @@ def reload(db, filename, yes, load_sysinfo, no_service_restart, disable_arp_cach
         else:
             cfg_hwsku = cfg_hwsku.strip()
 
-    # For dual ToR devices, cache ARP and FDB info
-    localhost_metadata = db.cfgdb.get_table('DEVICE_METADATA')['localhost']
-    cache_arp_table = not disable_arp_cache and 'subtype' in localhost_metadata and localhost_metadata['subtype'].lower() == 'dualtor'
-
-    if cache_arp_table:
-        cache_arp_entries()
-
     #Stop services before config push
     if not no_service_restart:
         log.log_info("'reload' stopping services...")