ntp: T4909: Rewrite NTP op mode in new format

ntp: T4909: Rewrite NTP op mode in new format

Adapts ntp.xml.in to reference new ntp.py file
Add ntp.py
Adds a check to ntp.py to verify if the ntp service is configured
Adds raw mode to ntp.py
For raw output, replaces the original method of parsing the command line output FROM re.split+regex TO csv.reader.
Separates chrony commands into equivalent functions show_tracking, show_sources, source_sourcestats and show_activity
Revises the names of raw dictionary keys variables to be lowercase
Corrects a comment typo and renames function  name used for raw mode

(cherry picked from commit d2a82c3)

op-mode-definitions/ntp.xml.in

@@ -6,13 +6,25 @@
         <properties>
           <help>Show peer status of NTP daemon</help>
         </properties>
-        <command>${vyos_op_scripts_dir}/show_ntp.sh --sourcestats</command>
+        <command>${vyos_op_scripts_dir}/ntp.py show_sourcestats</command>
         <children>
+          <node name="activity">
+            <properties>
+              <help>Report the number of servers and peers that are online and offline</help>
+            </properties>
+            <command>${vyos_op_scripts_dir}/ntp.py show_activity</command>
+          </node>
+          <node name="sources">
+            <properties>
+              <help>Show information about the current time sources being accessed</help>
+            </properties>
+            <command>${vyos_op_scripts_dir}/ntp.py show_sources</command>
+          </node>
           <node name="system">
             <properties>
               <help>Show parameters about the system clock performance</help>
             </properties>
-            <command>${vyos_op_scripts_dir}/show_ntp.sh --tracking</command>
+            <command>${vyos_op_scripts_dir}/ntp.py show_tracking</command>
           </node>
         </children>
       </node>

src/op_mode/ntp.py

@@ -0,0 +1,164 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2024 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 csv
+import sys
+from itertools import chain
+
+import vyos.opmode
+from vyos.configquery import ConfigTreeQuery
+from vyos.utils.process import cmd
+
+def _get_raw_data(command: str) -> dict:
+    # Returns returns chronyc output as a dictionary
+
+    # Initialize dictionary keys to align with output of
+    # chrony -c. From some commands, its -c switch outputs
+    # more parameters, make sure to include them all below.
+    # See to chronyc(1) for definition of key variables
+    match command:
+        case "chronyc -c activity":
+            keys: list = [
+            'sources_online',
+            'sources_offline',
+            'sources_doing_burst_return_online',
+            'sources_doing_burst_return_offline',
+            'sources_with_unknown_address'
+            ]
+
+        case "chronyc -c sources":
+            keys: list = [
+            'm',
+            's',
+            'name_ip_address',
+            'stratum',
+            'poll',
+            'reach',
+            'last_rx',
+            'last_sample_adj_offset',
+            'last_sample_mes_offset',
+            'last_sample_est_error'
+            ]
+
+        case "chronyc -c sourcestats":
+            keys: list = [
+            'name_ip_address',
+            'np',
+            'nr',
+            'span',
+            'frequency',
+            'freq_skew',
+            'offset',
+            'std_dev'
+            ]
+
+        case "chronyc -c tracking":
+            keys: list = [
+            'ref_id',
+            'ref_id_name',
+            'stratum',
+            'ref_time',
+            'system_time',
+            'last_offset',
+            'rms_offset',
+            'frequency',
+            'residual_freq',
+            'skew',
+            'root_delay',
+            'root_dispersion',
+            'update_interval',
+            'leap_status'
+            ]
+
+        case _:
+            raise ValueError(f"Raw mode: of {command} is not implemented")
+
+    # Get -c option command line output, splitlines,
+    # and save comma-separated values as a flat list
+    output = cmd(command).splitlines()
+    values = csv.reader(output)
+    values = list(chain.from_iterable(values))
+
+    # Divide values into chunks of size keys and transpose
+    if len(values) > len(keys):
+       values = _chunk_list(values,keys)
+       values = zip(*values)
+
+    return dict(zip(keys, values))
+
+def _chunk_list(in_list, n):
+    # Yields successive n-sized chunks from in_list
+    for i in range(0, len(in_list), len(n)):
+        yield in_list[i:i + len(n)]
+
+def _is_configured():
+    # Check if ntp is configured
+    config = ConfigTreeQuery()
+    if not config.exists("service ntp"):
+        raise vyos.opmode.UnconfiguredSubsystem("NTP service is not enabled.")
+
+def show_activity(raw: bool):
+    _is_configured()
+    command = f'chronyc'
+
+    if raw:
+       command += f" -c activity"
+       return _get_raw_data(command)
+    else:
+       command += f" activity"
+       return cmd(command)
+
+def show_sources(raw: bool):
+    _is_configured()
+    command = f'chronyc'
+
+    if raw:
+       command += f" -c sources"
+       return _get_raw_data(command)
+    else:
+       command += f" sources -v"
+       return cmd(command)
+
+def show_tracking(raw: bool):
+    _is_configured()
+    command = f'chronyc'
+
+    if raw:
+       command += f" -c tracking"
+       return _get_raw_data(command)
+    else:
+       command += f" tracking"
+       return cmd(command)
+
+def show_sourcestats(raw: bool):
+    _is_configured()
+    command = f'chronyc'
+
+    if raw:
+       command += f" -c sourcestats"
+       return _get_raw_data(command)
+    else:
+       command += f" sourcestats -v"
+       return cmd(command)
+
+if __name__ == '__main__':
+    try:
+        res = vyos.opmode.run(sys.modules[__name__])
+        if res:
+            print(res)
+    except (ValueError, vyos.opmode.Error) as e:
+        print(e)
+        sys.exit(1)