FRR: T4020: Added CLI options for FRR daemons

Added first CLI items for controlling FRR daemons parameters that
cannot be changed via vtysh and are available via arguments only. Now
it is possible to enable/disable modules: SNMP (for each daemon),
BMP (for BGP), IRDP (for Zebra).

1 files changed, 173 insertions, 0 deletions

diff --git a/src/conf_mode/system_frr.py b/src/conf_mode/system_frr.py
new file mode 100755
index 000000000..cc47aa5be
--- /dev/null
+++ b/src/conf_mode/system_frr.py
@@ -0,0 +1,173 @@
+#!/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/>.
+
+from pathlib import Path
+from re import compile as re_compile
+from re import M as re_M
+from sys import exit
+
+from vyos import ConfigError
+from vyos import airbag
+from vyos.config import Config
+from vyos.logger import syslog
+from vyos.util import read_file, write_file, run
+airbag.enable()
+
+# path to daemons config and config status files
+config_file = '/etc/frr/daemons'
+vyos_status_file = '/tmp/vyos-config-status'
+# path to watchfrr for FRR control
+watchfrr = '/usr/lib/frr/watchfrr.sh'
+
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['system', 'frr']
+    if not conf.exists(base):
+        return {}
+
+    frr_config = conf.get_config_dict(base)
+
+    return frr_config
+
+
+def daemons_config_parse(daemons_config):
+    # create regex for parsing daemons options
+    regex_daemon_config = re_compile(
+        r'^(?P<daemon_name>\w+)_options="(?P<daemon_options>.*)"$', re_M)
+    # create empty dict for config
+    daemons_config_dict = {}
+    # fill dictionary with actual config
+    for daemon in regex_daemon_config.finditer(daemons_config):
+        daemon_name = daemon.group('daemon_name')
+        daemon_options = daemon.group('daemon_options')
+        daemons_config_dict[daemon_name] = daemon_options
+
+    # return daemons config
+    return (daemons_config_dict)
+
+
+def verify(frr_config):
+    # Nothing to verify here
+    pass
+
+
+def generate(frr_config):
+    # read daemons config file
+    daemons_config = read_file(config_file)
+    daemons_config_current = daemons_config
+    daemons_config_dict = daemons_config_parse(daemons_config)
+
+    # configure SNMP integration
+    frr_snmp = frr_config.get('frr', {}).get('snmp', {})
+    # prepare regex for matching modules
+    regex_snmp = re_compile(r'^.* -M snmp.*$')
+    regex_bmp = re_compile(r'^.* -M bmp.*$')
+    regex_irdp = re_compile(r'^.* -M irdp.*$')
+    # check each daemon's config
+    for (daemon_name, daemon_options) in daemons_config_dict.items():
+        # check if SNMP integration is enabled in the config file
+        snmp_enabled = regex_snmp.match(daemon_options)
+        # check if BMP is enabled in the config file
+        bmp_enabled = regex_bmp.match(daemon_options)
+        # check if IRDP is enabled in the config file
+        irdp_enabled = regex_irdp.match(daemon_options)
+
+        # enable SNMP integration
+        if daemon_name in frr_snmp and not snmp_enabled:
+            daemon_options_new = f'{daemon_options} -M snmp'
+            daemons_config = daemons_config.replace(
+                f'{daemon_name}_options=\"{daemon_options}\"',
+                f'{daemon_name}_options=\"{daemon_options_new}\"')
+            daemon_options = daemon_options_new
+        # disable SNMP integration
+        if daemon_name not in frr_snmp and snmp_enabled:
+            daemon_options_new = daemon_options.replace(' -M snmp', '')
+            daemons_config = daemons_config.replace(
+                f'{daemon_name}_options=\"{daemon_options}\"',
+                f'{daemon_name}_options=\"{daemon_options_new}\"')
+            daemon_options = daemon_options_new
+
+        # enable BMP
+        if daemon_name == 'bgpd' and 'bmp' in frr_config.get(
+                'frr', {}) and not bmp_enabled:
+            daemon_options_new = f'{daemon_options} -M bmp'
+            daemons_config = daemons_config.replace(
+                f'{daemon_name}_options=\"{daemon_options}\"',
+                f'{daemon_name}_options=\"{daemon_options_new}\"')
+            daemon_options = daemon_options_new
+        # disable BMP
+        if daemon_name == 'bgpd' and 'bmp' not in frr_config.get(
+                'frr', {}) and bmp_enabled:
+            daemon_options_new = daemon_options.replace(' -M bmp', '')
+            daemons_config = daemons_config.replace(
+                f'{daemon_name}_options=\"{daemon_options}\"',
+                f'{daemon_name}_options=\"{daemon_options_new}\"')
+            daemon_options = daemon_options_new
+
+        # enable IRDP
+        if daemon_name == 'zebra' and 'irdp' in frr_config.get(
+                'frr', {}) and not irdp_enabled:
+            daemon_options_new = f'{daemon_options} -M irdp'
+            daemons_config = daemons_config.replace(
+                f'{daemon_name}_options=\"{daemon_options}\"',
+                f'{daemon_name}_options=\"{daemon_options_new}\"')
+            daemon_options = daemon_options_new
+        # disable IRDP
+        if daemon_name == 'zebra' and 'irdp' not in frr_config.get(
+                'frr', {}) and irdp_enabled:
+            daemon_options_new = daemon_options.replace(' -M irdp', '')
+            daemons_config = daemons_config.replace(
+                f'{daemon_name}_options=\"{daemon_options}\"',
+                f'{daemon_name}_options=\"{daemon_options_new}\"')
+
+    # update configuration file if this is necessary
+    if daemons_config != daemons_config_current:
+        write_file(config_file, daemons_config)
+        frr_config['config_file_changed'] = True
+
+
+def apply(frr_config):
+    # check if this is initial commit during boot or intiated by CLI
+    # if the file exists, this must be CLI commit
+    commit_type_cli = Path(vyos_status_file).exists()
+    # display warning to user
+    if commit_type_cli and frr_config.get('config_file_changed'):
+        # Since FRR restart is not safe thing, better to give
+        # control over this to users
+        print('''
+        You need to reboot a router (preferred) or restart FRR
+        to apply changes in modules settings
+        ''')
+    # restart FRR automatically. DUring the initial boot this should be
+    # safe in most cases
+    if not commit_type_cli and frr_config.get('config_file_changed'):
+        syslog.warning('Restarting FRR to apply changes in modules')
+        run(f'{watchfrr} restart')
+
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)