Option to enable network-segment-range support

To let operators add an additional and optional service plugin into the
deployment configuration as "network_segment_range".
https://docs.openstack.org/neutron/latest/admin/config-network-segment-ranges.html

Closes-Bug: #1965229
Change-Id: Id0ac7c397874ad2c51935e8c0eab64f1ef4f6fd3

config.yaml

@@ -807,3 +807,9 @@ options:
       If True, on Stein or later attribute 'propagate_uplink_status' will be
       available to port. This attribute can be implemented for VF port to
       indicate if the VF link state should follow the state of the PF.
+  enable-network-segment-range:
+    type: boolean
+    default: False
+    description: |
+      Setting this to True will enable network segment ranges (Stein and
+      later).

hooks/neutron_api_context.py

@@ -317,6 +317,27 @@ def is_fwaas_enabled(cmp_release=None):
     return False
 
 
+def is_network_segment_range_enabled():
+    """
+    Check if Network segment ranges feature should be enabled.
+
+    returns: True if enable-network-segment-range config is True,
+        otherwise False.
+    :rtype: boolean
+    """
+    if config('enable-network-segment-range'):
+
+        if CompareOpenStackReleases(os_release('neutron-server')) < 'stein':
+            log("The network segment ranges option is"
+                "only supported on Stein or later",
+                ERROR)
+            return False
+
+        return True
+
+    return False
+
+
 def is_vlan_trunking_requested_and_valid():
     """Check whether VLAN trunking should be enabled by checking whether
        it has been requested and, if it has, is it supported in the current
@@ -715,6 +736,9 @@ class NeutronCCContext(context.NeutronContext):
             if is_port_forwarding_enabled():
                 ctxt['service_plugins'].append('port_forwarding')
 
+            if is_network_segment_range_enabled():
+                ctxt['service_plugins'].append('network_segment_range')
+
             if is_qos_requested_and_valid():
                 ctxt['service_plugins'].append('qos')
 

unit_tests/test_neutron_api_context.py

@@ -294,6 +294,21 @@ class GeneralTests(CharmTestCase):
         self.test_config.set('enable-fwaas', False)
         self.assertFalse(context.is_fwaas_enabled())
 
+    def test_is_network_segment_range_enabled(self):
+        # Test pre-stein release
+        self.os_release.return_value = 'rocky'
+        self.test_config.set('enable-network-segment-range', True)
+        self.assertFalse(context.is_network_segment_range_enabled())
+        self.test_config.set('enable-network-segment-range', False)
+        self.assertFalse(context.is_network_segment_range_enabled())
+
+        # Test stein release
+        self.os_release.return_value = 'stein'
+        self.test_config.set('enable-network-segment-range', True)
+        self.assertTrue(context.is_network_segment_range_enabled())
+        self.test_config.set('enable-network-segment-range', False)
+        self.assertFalse(context.is_network_segment_range_enabled())
+
 
 class IdentityServiceContext(CharmTestCase):