conntrack-sync: T3535: Rewrite conf and op modes to XML python style

1 files changed, 135 insertions, 0 deletions

diff --git a/src/conf_mode/conntrack_sync.py b/src/conf_mode/conntrack_sync.py
new file mode 100755
index 000000000..7f22fa2dd
--- /dev/null
+++ b/src/conf_mode/conntrack_sync.py
@@ -0,0 +1,135 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# 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 os
+
+from sys import exit
+from vyos.config import Config
+from vyos.configdict import dict_merge
+from vyos.configverify import verify_interface_exists
+from vyos.util import call
+from vyos.util import dict_search
+from vyos.util import process_named_running
+from vyos.util import read_file
+from vyos.util import run
+from vyos.template import render
+from vyos.template import get_ipv4
+from vyos.validate import is_addr_assigned
+from vyos.xml import defaults
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+config_file = '/run/conntrackd/conntrackd.conf'
+
+def resync_vrrp():
+    tmp = run('/usr/libexec/vyos/conf_mode/vrrp.py')
+    if tmp > 0:
+        print('ERROR: error restarting VRRP daemon!')
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['service', 'conntrack-sync']
+    if not conf.exists(base):
+        return None
+
+    conntrack = conf.get_config_dict(base, key_mangling=('-', '_'),
+                                     get_first_key=True)
+    # We have gathered the dict representation of the CLI, but there are default
+    # options which we need to update into the dictionary retrived.
+    default_values = defaults(base)
+    conntrack = dict_merge(default_values, conntrack)
+
+    conntrack['hash_size'] = read_file('/sys/module/nf_conntrack/parameters/hashsize')
+    conntrack['table_size'] = read_file('/proc/sys/net/netfilter/nf_conntrack_max')
+
+    conntrack['vrrp'] = conf.get_config_dict(['high-availability', 'vrrp', 'sync-group'],
+                                     get_first_key=True)
+
+    return conntrack
+
+def verify(conntrack):
+    if not conntrack:
+        return None
+
+    if 'interface' not in conntrack:
+        raise ConfigError('Interface not defined!')
+
+    for interface in conntrack['interface']:
+        verify_interface_exists(interface)
+        # Interface must not only exist, it must also carry an IP address
+        if len(get_ipv4(interface)) < 1:
+            raise ConfigError(f'Interface {interface} requires an IP address!')
+
+    if 'expect_sync' in conntrack:
+        if len(conntrack['expect_sync']) > 1 and 'all' in conntrack['expect_sync']:
+            raise ConfigError('Cannot configure all with other protocol')
+
+    if 'listen_address' in conntrack:
+        address = conntrack['listen_address']
+        if not is_addr_assigned(address):
+            raise ConfigError(f'Specified listen-address {address} not assigned to any interface!')
+
+    vrrp_group = dict_search('failover_mechanism.vrrp.sync_group', conntrack)
+    if vrrp_group == None:
+        raise ConfigError(f'No VRRP sync-group defined!')
+    if vrrp_group not in conntrack['vrrp']:
+        raise ConfigError(f'VRRP sync-group {vrrp_group} not configured!')
+
+    return None
+
+def generate(conntrack):
+    if not conntrack:
+        if os.path.isfile(config_file):
+            os.unlink(config_file)
+        return None
+
+    render(config_file, 'conntrackd/conntrackd.conf.tmpl', conntrack)
+
+    return None
+
+def apply(conntrack):
+    if not conntrack:
+        # Failover mechanism daemon should be indicated that it no longer needs
+        # to execute conntrackd actions on transition. This is only required
+        # once when conntrackd is stopped and taken out of service!
+        if process_named_running('conntrackd'):
+            resync_vrrp()
+
+        call('systemctl stop conntrackd.service')
+        return None
+
+    # Failover mechanism daemon should be indicated that it needs to execute
+    # conntrackd actions on transition. This is only required once when conntrackd
+    # is started the first time!
+    if not process_named_running('conntrackd'):
+        resync_vrrp()
+
+    call('systemctl restart conntrackd.service')
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)