T775: Add service config-sync between 2 routers

Service config-sync allows synchronizing a section of
the configuration.
As PoC allow only nat, nat66 and firewall sections

Rertreive the configuration for a section from self node and
send this configuration to the section of the 'secondary' node.

This feature adds a symlink from helper 'vyos_config_sync.py'
to '/config/scripts/commit/post-hooks.d' and config that is
located in '/run/config_sync_conf.conf'
It will synchronyze the config only if the setcion
was changed.

set service config-sync secondary address 192.0.2.11
set service config-sync secondary key xxx
set service config-sync section nat
set service config-sync section nat66
set service config-sync section firewall
set service config-sync mode load

1 files changed, 190 insertions, 0 deletions

diff --git a/src/helpers/vyos_config_sync.py b/src/helpers/vyos_config_sync.py
new file mode 100755
index 000000000..6e66a6be0
--- /dev/null
+++ b/src/helpers/vyos_config_sync.py
@@ -0,0 +1,190 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 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
+import json
+import requests
+import urllib3
+import logging
+from typing import Optional, List, Union, Dict, Any
+
+from vyos.config import Config
+
+
+CONFIG_FILE = '/run/config_sync_conf.conf'
+
+# Logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+logger.name = os.path.basename(__file__)
+
+# API
+API_HEADERS = {'Content-Type': 'application/json'}
+
+
+def post_request(url: str,
+                 data: str,
+                 headers: Dict[str, str]) -> requests.Response:
+    """Sends a POST request to the specified URL
+
+    Args:
+        url (str): The URL to send the POST request to.
+        data (Dict[str, Any]): The data to send with the POST request.
+        headers (Dict[str, str]): The headers to include with the POST request.
+
+    Returns:
+        requests.Response: The response object representing the server's response to the request
+    """
+
+    response = requests.post(url,
+                             data=data,
+                             headers=headers,
+                             verify=False,
+                             timeout=timeout)
+    return response
+
+
+def retrieve_config(section: str = None) -> Optional[Dict[str, Any]]:
+    """Retrieves the configuration from the local server.
+
+    Args:
+        section: str: The section of the configuration to retrieve. Default is None.
+
+    Returns:
+        Optional[Dict[str, Any]]: The retrieved configuration as a dictionary, or None if an error occurred.
+    """
+    if section is None:
+        section = []
+    else:
+        section = section.split()
+
+    conf = Config()
+    config = conf.get_config_dict(section, get_first_key=True)
+    if config:
+        return config
+    return None
+
+
+def set_remote_config(
+        address: str,
+        key: str,
+        op: str,
+        path: str = None,
+        section: Optional[str] = None) -> Optional[Dict[str, Any]]:
+    """Loads the VyOS configuration in JSON format to a remote host.
+
+    Args:
+        address (str): The address of the remote host.
+        key (str): The key to use for loading the configuration.
+        path (Optional[str]): The path of the configuration. Default is None.
+        section (Optional[str]): The section of the configuration to load. Default is None.
+
+    Returns:
+        Optional[Dict[str, Any]]: The response from the remote host as a dictionary, or None if an error occurred.
+    """
+
+    if path is None:
+        path = []
+    else:
+        path = path.split()
+    headers = {'Content-Type': 'application/json'}
+
+    # Disable the InsecureRequestWarning
+    urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
+
+    url = f'https://{address}/configure-section'
+    data = json.dumps({
+        'op': mode,
+        'path': path,
+        'section': section,
+        'key': key
+    })
+
+    try:
+        config = post_request(url, data, headers)
+        return config.json()
+    except requests.exceptions.RequestException as e:
+        print(f"An error occurred: {e}")
+        logger.error(f"An error occurred: {e}")
+        return None
+
+
+def is_section_revised(section: str) -> bool:
+    from vyos.config_mgmt import is_node_revised
+    return is_node_revised([section])
+
+
+def config_sync(secondary_address: str,
+                secondary_key: str,
+                sections: List[str],
+                mode: str):
+    """Retrieve a config section from primary router in JSON format and send it to
+       secondary router
+    """
+    # Config sync only if sections changed
+    if not any(map(is_section_revised, sections)):
+        return
+
+    logger.info(
+        f"Config synchronization: Mode={mode}, Secondary={secondary_address}"
+    )
+
+    # Sync sections ("nat", "firewall", etc)
+    for section in sections:
+        config_json = retrieve_config(section=section)
+        # Check if config path deesn't exist, for example "set nat"
+        # we set empty value for config_json data
+        # As we cannot send to the remote host section "nat None" config
+        if not config_json:
+            config_json = ""
+        logger.debug(
+            f"Retrieved config for section '{section}': {config_json}")
+        set_config = set_remote_config(address=secondary_address,
+                                       key=secondary_key,
+                                       op=mode,
+                                       path=section,
+                                       section=config_json)
+        logger.debug(f"Set config for section '{section}': {set_config}")
+
+
+if __name__ == '__main__':
+    # Read configuration from file
+    if not os.path.exists(CONFIG_FILE):
+        logger.error(f"Post-commit: No config file '{CONFIG_FILE}' exists")
+        exit(0)
+
+    with open(CONFIG_FILE, 'r') as f:
+        config_data = f.read()
+
+    config = json.loads(config_data)
+
+    mode = config.get('mode')
+    secondary_address = config.get('secondary', {}).get('address')
+    secondary_key = config.get('secondary', {}).get('key')
+    sections = config.get('section')
+    timeout = int(config.get('secondary', {}).get('timeout'))
+
+    if not all([
+            mode, secondary_address, secondary_key, sections
+    ]):
+        logger.error(
+            "Missing required configuration data for config synchronization.")
+        exit(0)
+
+    config_sync(secondary_address, secondary_key,
+                sections, mode)