VPP: T7175: Add sFlow conf mode CLI and startup template (#32)

* VPP: T7175
Added conf mode CLI for VPP sflow plugin and updated VPP template to include plugin.

* VPP: T7175: Conf mode CLI and startup template.

* T7175: VPP fix sFlow verify use vpp enstead of enable_vpp

* T7175: VPP add sFlow smoketest

* T7175: VPP remove unused config_changed variable

---------

Co-authored-by: Viacheslav <v.gletenko@vyos.io>

2 files changed, 149 insertions, 0 deletions

diff --git a/src/conf_mode/vpp.py b/src/conf_mode/vpp.py
index 9b9a3466b..0ea8d261b 100755
--- a/src/conf_mode/vpp.py
+++ b/src/conf_mode/vpp.py
@@ -149,6 +149,10 @@ def get_config(config=None):
     if conf.exists(['vpp', 'nat', 'cgnat']):
         set_dependents('vpp_nat_cgnat', conf)
 
+    # sFlow dependency
+    if conf.exists(['vpp', 'sflow']):
+        set_dependents('vpp_sflow', conf)
+
     # ACL dependency
     if conf.exists(['vpp', 'acl']):
         set_dependents('vpp_acl', conf)
diff --git a/src/conf_mode/vpp_sflow.py b/src/conf_mode/vpp_sflow.py
new file mode 100644
index 000000000..ebe91617b
--- /dev/null
+++ b/src/conf_mode/vpp_sflow.py
@@ -0,0 +1,145 @@
+# Copyright (C) 2025 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 vyos import ConfigError
+from vyos.config import Config
+from vyos.vpp.utils import cli_ifaces_list
+from vyos.vpp import VPPControl
+
+
+def get_config(config=None) -> dict:
+    if config:
+        conf = config
+    else:
+        conf = Config()
+
+    base = ['vpp', 'sflow']
+
+    # Get config_dict with default values
+    config = conf.get_config_dict(
+        base,
+        key_mangling=('-', '_'),
+        get_first_key=True,
+        no_tag_node_value_mangle=True,
+        with_defaults=True,
+        with_recursive_defaults=True,
+    )
+
+    # Get effective config as we need full dictionary for deletion
+    effective_config = conf.get_config_dict(
+        base,
+        key_mangling=('-', '_'),
+        effective=True,
+        get_first_key=True,
+        no_tag_node_value_mangle=True,
+    )
+
+    # Get system sflow configuration to check for server
+    system_sflow = conf.get_config_dict(
+        ['system', 'sflow'],
+        key_mangling=('-', '_'),
+        get_first_key=True,
+        no_tag_node_value_mangle=True,
+    )
+
+    if system_sflow:
+        config['system_sflow'] = system_sflow
+
+    if not config:
+        config['remove'] = True
+        return config
+
+    # Add list of VPP interfaces to the config
+    config.update({'vpp_ifaces': cli_ifaces_list(conf)})
+
+    if effective_config:
+        config.update({'effective': effective_config})
+
+    return config
+
+
+def verify(config):
+    if 'remove' in config:
+        return None
+
+    # Check if interface section exists
+    if 'interface' not in config:
+        return None
+
+    # Verify that all interfaces specified exist in VPP
+    for interface in config['interface']:
+        if interface not in config['vpp_ifaces']:
+            raise ConfigError(
+                f'{interface} must be a VPP interface for sFlow monitoring'
+            )
+
+    # Verify sample rate is a positive integer
+    if 'sample_rate' in config:
+        try:
+            sample_rate = int(config['sample_rate'])
+            if sample_rate <= 0:
+                raise ConfigError('sFlow sample rate must be a positive integer')
+        except ValueError:
+            raise ConfigError('sFlow sample rate must be a valid integer')
+
+    # Verify that system sflow has enable-vpp defined
+    if 'system_sflow' not in config or 'vpp' not in config.get('system_sflow', {}):
+        raise ConfigError(
+            'sFlow enable-vpp must be defined under system sflow configuration'
+        )
+
+
+def generate(config):
+    # No templates to render for sFlow
+    pass
+
+
+def apply(config):
+    # Initialize VPP control API
+    vpp = VPPControl(attempts=20, interval=500)
+
+    if 'remove' in config:
+        # Disable sFlow on all interfaces
+        for interface in config.get('effective', {}).get('interface', []):
+            vpp.cli_cmd(f'sflow enable-disable {interface} disable')
+        return None
+
+    # Configure sample rate if specified
+    if 'sample_rate' in config:
+        vpp.cli_cmd(f'sflow sampling-rate {config["sample_rate"]}')
+
+    # Configure interfaces
+    if 'interface' in config:
+        # Enable sFlow on specified interfaces
+        for interface in config['interface']:
+            vpp.cli_cmd(f'sflow enable-disable {interface}')
+
+        # Disable sFlow on interfaces that were removed from config
+        effective_interfaces = config.get('effective', {}).get('interface', [])
+        if effective_interfaces:
+            for interface in effective_interfaces:
+                if interface not in config['interface']:
+                    vpp.cli_cmd(f'sflow enable-disable {interface} disable')
+
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)