T7556: VPP add IPFIX collector configuration

Add VPP IPFIX configuration commands:

```
set vpp ipfix active-timeout '8'
set vpp ipfix collector 192.0.2.2 port '2055'
set vpp ipfix collector 192.0.2.2 source-address '192.0.2.1'
set vpp ipfix flowprobe-record 'l2'
set vpp ipfix flowprobe-record 'l3'
set vpp ipfix flowprobe-record 'l4'
set vpp ipfix inactive-timeout '32'
set vpp ipfix interface eth0
set vpp ipfix interface eth1 direction 'both'
set vpp ipfix interface eth1 flow-variant 'ipv4'
```

1 files changed, 165 insertions, 0 deletions

diff --git a/src/op_mode/vpp.py b/src/op_mode/vpp.py
new file mode 100755
index 000000000..fea874909
--- /dev/null
+++ b/src/op_mode/vpp.py
@@ -0,0 +1,165 @@
+#!/usr/bin/env python3
+#
+# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# 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 sys
+import typing
+
+from tabulate import tabulate
+from vyos.vpp import VPPControl
+from vyos.configquery import ConfigTreeQuery
+import vyos.opmode
+
+
+class VPPShow:
+    def __init__(self):
+        self.config = ConfigTreeQuery()
+        self.vpp = VPPControl()
+
+    # -----------------------------
+    # IPFIX Interfaces
+    # -----------------------------
+    def _get_ipfix_interfaces_raw(self) -> typing.List[dict]:
+        interfaces = self.vpp.api.flowprobe_interface_dump()
+        index_map = {
+            i.sw_if_index: i.interface_name for i in self.vpp.api.sw_interface_dump()
+        }
+
+        return [
+            {
+                'interface': index_map.get(e.sw_if_index, f'if{e.sw_if_index}'),
+                'sw_if_index': e.sw_if_index,
+                'which': e.which.name.replace('FLOWPROBE_WHICH_', '').lower(),
+                'direction': e.direction.name.replace(
+                    'FLOWPROBE_DIRECTION_', ''
+                ).lower(),
+            }
+            for e in interfaces
+        ]
+
+    def _show_ipfix_interfaces_formatted(self, data: typing.List[dict]) -> str:
+        if not data:
+            return 'No flowprobe interfaces configured.'
+        table_data = [
+            {
+                'Interface': d['interface'],
+                'VppIfIndex': d['sw_if_index'],
+                'Flow-variant': d['which'],
+                'Direction': d['direction'],
+            }
+            for d in data
+        ]
+        return tabulate(table_data, headers='keys', tablefmt='simple')
+
+    def ipfix_interfaces(self, raw: bool):
+        base = ['vpp', 'ipfix', 'interface']
+        if not self.config.exists(base):
+            raise vyos.opmode.UnconfiguredSubsystem(
+                'vpp ipfix interface is not configured'
+            )
+
+        data = self._get_ipfix_interfaces_raw()
+        return data if raw else self._show_ipfix_interfaces_formatted(data)
+
+    # -----------------------------
+    # IPFIX Collectors
+    # -----------------------------
+    def _get_ipfix_collectors_raw(self) -> typing.List[dict]:
+        _, collectors = self.vpp.api.ipfix_all_exporter_get()
+        return [
+            {
+                'collector_address': str(c.collector_address),
+                'collector_port': c.collector_port,
+                'src_address': str(c.src_address),
+                'vrf_id': c.vrf_id,
+                'path_mtu': c.path_mtu,
+                'template_interval': c.template_interval,
+                'udp_checksum': bool(c.udp_checksum),
+            }
+            for c in collectors
+        ]
+
+    def _show_ipfix_collectors_formatted(self, data: typing.List[dict]) -> str:
+        if not data:
+            return 'No IPFIX collectors configured.'
+        table_data = [
+            {
+                'Collector': f"{d['collector_address']}:{d['collector_port']}",
+                'Source': d['src_address'],
+                'VRF': d['vrf_id'],
+                'MTU': d['path_mtu'],
+                'Template Intvl': d['template_interval'],
+                'UDP Cksum': 'on' if d['udp_checksum'] else 'off',
+            }
+            for d in data
+        ]
+        return tabulate(table_data, headers='keys', tablefmt='simple')
+
+    def ipfix_collectors(self, raw: bool):
+        base = ['vpp', 'ipfix', 'collector']
+        if not self.config.exists(base):
+            raise vyos.opmode.UnconfiguredSubsystem(
+                'vpp ipfix collector is not configured'
+            )
+
+        data = self._get_ipfix_collectors_raw()
+        return data if raw else self._show_ipfix_collectors_formatted(data)
+
+    # -----------------------------
+    # IPFIX table
+    # -----------------------------
+    def _get_ipfix_table_raw(self):
+        # VPP does not have API call to get this data
+        data = self.vpp.cli_cmd('show flowprobe table')
+        return [data.reply]
+
+    def _show_ipfix_table_formatted(self) -> str:
+        data = self.vpp.cli_cmd('show flowprobe table')
+        return data.reply
+
+    def ipfix_table(self, raw: bool):
+        base = ['vpp', 'ipfix', 'collector']
+        if not self.config.exists(base):
+            raise vyos.opmode.UnconfiguredSubsystem(
+                'vpp ipfix collector is not configured'
+            )
+
+        data = self._get_ipfix_table_raw()
+        return data if raw else self._show_ipfix_table_formatted()
+
+
+# -----------------------------
+# VyOS IPFIX op-mode entries
+# -----------------------------
+def show_ipfix_interfaces(raw: bool):
+    return VPPShow().ipfix_interfaces(raw)
+
+
+def show_ipfix_collectors(raw: bool):
+    return VPPShow().ipfix_collectors(raw)
+
+
+def show_ipfix_table(raw: bool):
+    return VPPShow().ipfix_table(raw)
+
+
+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)