gc: Fix trunk vlans for ovs port in gen_conf

The `nmstatectl gc` will fail on OVS trunk VLAN state like:

```yml
---
interfaces:
  - name: br0
    type: ovs-bridge
    state: up
    bridge:
      port:
        - name: eth1
          vlan:
            mode: trunk
            trunk-tags:
            - id: 500
```

Integration test case included.

Signed-off-by: Koen de Laat <koen.de.laat@philips.com>

examples/ovsbridge_vlan_port.yml

@@ -3,6 +3,9 @@ interfaces:
   - name: ovs0
     type: ovs-interface
     state: up
+  - name: ovs1
+    type: ovs-interface
+    state: up
   - name: ovs-br0
     type: ovs-bridge
     state: up
@@ -12,3 +15,11 @@ interfaces:
           vlan:
             mode: access
             tag: 2
+        - name: ovs1
+          vlan:
+            mode: trunk
+            trunk-tags:
+              - id: 1
+              - id-range:
+                  min: 10
+                  max: 20

rust/src/lib/nm/nm_dbus/gen_conf/ovs.rs

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: Apache-2.0
 
+use crate::nm::nm_dbus::ToDbusValue;
 use std::collections::HashMap;
 
 use super::super::{
@@ -9,11 +10,41 @@ use super::super::{
 };
 
 impl ToKeyfile for NmSettingOvsBridge {}
-impl ToKeyfile for NmSettingOvsPort {}
 impl ToKeyfile for NmSettingOvsIface {}
 impl ToKeyfile for NmSettingOvsPatch {}
 impl ToKeyfile for NmSettingOvsDpdk {}
 
+impl ToKeyfile for NmSettingOvsPort {
+    fn to_keyfile(&self) -> Result<HashMap<String, zvariant::Value>, NmError> {
+        let mut ret = HashMap::new();
+
+        for (k, v) in self.to_value()?.drain() {
+            if k != "trunks" {
+                ret.insert(k.to_string(), v);
+            }
+        }
+        if let Some(vlans) = self.trunks.as_ref() {
+            let mut vlans_clone = vlans.clone();
+            vlans_clone.sort_unstable_by_key(|v| v.start);
+            let mut vlans_str = Vec::new();
+            for vlan in vlans_clone {
+                let ret = if vlan.start == vlan.end {
+                    vlan.start.to_string()
+                } else {
+                    format!("{}-{}", vlan.start, vlan.end)
+                };
+                vlans_str.push(ret);
+            }
+            ret.insert(
+                "trunks".to_string(),
+                zvariant::Value::new(vlans_str.join(",")),
+            );
+        }
+
+        Ok(ret)
+    }
+}
+
 impl ToKeyfile for NmSettingOvsExtIds {
     fn to_keyfile(&self) -> Result<HashMap<String, zvariant::Value>, NmError> {
         let mut ret = HashMap::new();

tests/integration/nm/gen_conf_test.py

@@ -13,6 +13,7 @@
 from libnmstate.schema import RouteRule
 from libnmstate.schema import LLDP
 
+from ..testlib import assertlib
 from ..testlib import iprule
 from ..testlib.env import is_k8s
 from ..testlib.env import nm_minor_version
@@ -67,6 +68,42 @@ def test_gen_conf_ovs_same_name(eth1_up, cleanup_ovs_same_name):
         retry_verify_ovs_ports("br0", sorted(["eth1", "br0"]))
 
 
+@pytest.mark.tier1
+@pytest.mark.skipif(is_k8s(), reason="K8S does not support genconf")
+def test_gen_conf_ovs_trunk_vlan():
+    desired_state = load_yaml(
+        """
+interfaces:
+  - name: ovs0
+    type: ovs-interface
+    state: up
+  - name: ovs1
+    type: ovs-interface
+    state: up
+  - name: ovs-br0
+    type: ovs-bridge
+    state: up
+    bridge:
+      port:
+        - name: ovs0
+          vlan:
+            mode: access
+            tag: 10
+        - name: ovs1
+          vlan:
+            mode: trunk
+            trunk-tags:
+              - id: 1
+              - id-range:
+                  min: 10
+                  max: 20
+"""
+    )
+
+    with gen_conf_apply(desired_state):
+        assertlib.assert_state_match(desired_state)
+
+
 @pytest.mark.tier1
 def test_gen_conf_routes_rules():
     desired_state = load_yaml(