Enable internal dns by default with a default dns name

Add dns-domain config option in neutron-k8s to allow building instances
within an internal domain.

Always enable extension dns_domain_ports.

Remove config option from openstack-hypervisor, as it is not the right
place.

Change-Id: I876269ba1b575ad108dc8c9defcc32dcf6044ba3

charms/neutron-k8s/config.yaml

@@ -3,6 +3,15 @@ options:
     default: False
     description: Enable debug logging.
     type: boolean
+  dns-domain:
+    default: cloud.sunbeam.local.
+    description: |
+      Specifies the dns domain name that should be used for building instance
+      hostnames. The value of 'openstacklocal' will cause
+      the dhcp agents to broadcast the default domain of openstacklocal and
+      will not enable internal cloud dns resolution. This value should end
+      with a '.', e.g. 'cloud.example.org.'.
+    type: string
   os-admin-hostname:
     default:
     description: |

charms/neutron-k8s/src/charm.py

@@ -20,7 +20,9 @@ This charm provide Neutron services as part of an OpenStack deployment
 """
 
 import logging
+import re
 
+import ops
 import ops_sunbeam.charm as sunbeam_charm
 import ops_sunbeam.config_contexts as sunbeam_ctxts
 import ops_sunbeam.container_handlers as sunbeam_chandlers
@@ -121,6 +123,63 @@ class NeutronOperatorCharm(sunbeam_charm.OSBaseOperatorAPICharm):
         ]
     ]
 
+    def check_configuration(self, event: ops.EventBase):
+        """Check a configuration key is correct."""
+        try:
+            self._validate_domain()
+        except ValueError as e:
+            raise sunbeam_guard.BlockedExceptionError(str(e)) from e
+
+    def _validate_domain(self):
+        """Check given domain is valid."""
+        domain = self.config.get("dns-domain")
+        if not domain:
+            raise ValueError("dns-domain cannot be empty")
+
+        if len(domain) > 253:
+            raise ValueError(
+                "A full name cannot be longer than 253 characters (trailing dot included)"
+            )
+
+        if not domain.endswith("."):
+            raise ValueError("A domain name must have a trailing dot (.)")
+
+        labels = domain.split(".")
+
+        if len(labels) == 1:
+            raise ValueError(
+                "A domain name must have at least one label and a trailing dot,"
+                " or two labels separated by a dot"
+            )
+
+        if domain.endswith("."):
+            # strip trailing dot
+            del labels[-1]
+
+        label_regex = re.compile(r"^[a-z0-9-]*$", re.IGNORECASE)
+
+        for label in labels:
+            if not 1 < len(label) < 63:
+                raise ValueError(
+                    "A label in a domain cannot be empty or longer than 63 characters"
+                )
+
+            if label.startswith("-") or label.endswith("-"):
+                raise ValueError(
+                    "A label in a domain cannot start or end with a hyphen (-)"
+                )
+
+            if label_regex.match(label) is None:
+                raise ValueError(
+                    "A label in a domain can only contain alphanumeric characters"
+                    " and hyphens (-)"
+                )
+
+    def configure_unit(self, event: ops.EventBase) -> None:
+        """Run configuration on this unit."""
+        self.check_configuration(event)
+        return super().configure_unit(event)
+
     def get_pebble_handlers(self) -> list[sunbeam_chandlers.PebbleHandler]:
         """Pebble handlers for the service."""
         return [
@@ -178,7 +237,7 @@ class OVNContext(sunbeam_ctxts.ConfigContext):
     def context(self) -> dict:
         """Configuration context."""
         return {
-            "extension_drivers": "port_security,qos",
+            "extension_drivers": "port_security,qos,dns_domain_ports",
             "type_drivers": "geneve,gre,vlan,flat,local",
             "tenant_network_types": "geneve,gre,vlan,flat,local",
             "mechanism_drivers": "ovn",

charms/neutron-k8s/src/templates/neutron.conf.j2

@@ -22,7 +22,7 @@ dhcp_agents_per_network = 1
 notify_nova_on_port_status_changes = True
 notify_nova_on_port_data_changes = True
 
-
+dns_domain = {{ options.dns_domain }}
 
 global_physnet_mtu = 1500
 

charms/openstack-hypervisor/config.yaml

@@ -10,9 +10,6 @@ options:
     description: |
       Whether to resume the guest VMs when the host boots.
     type: boolean
-  dns-domain:
-    default: "openstack.local"
-    type: string
   dns-servers:
     default: "8.8.8.8"
     type: string

charms/openstack-hypervisor/src/charm.py

@@ -429,7 +429,6 @@ class HypervisorOperatorCharm(sunbeam_charm.OSBaseOperatorCharm):
                 "identity.user-domain-name": contexts.identity_credentials.user_domain_name,
                 "identity.username": contexts.identity_credentials.username,
                 "logging.debug": config("debug"),
-                "network.dns-domain": config("dns-domain"),
                 "network.dns-servers": config("dns-servers"),
                 "network.enable-gateway": config("enable-gateway"),
                 "network.external-bridge": config("external-bridge"),

charms/openstack-hypervisor/tests/unit/test_charm.py

@@ -162,7 +162,6 @@ class TestCharm(test_utils.CharmTestCase):
             "identity.username": "username",
             "logging.debug": False,
             "monitoring.enable": False,
-            "network.dns-domain": "openstack.local",
             "network.dns-servers": "8.8.8.8",
             "network.enable-gateway": False,
             "network.external-bridge": "br-ex",
@@ -266,7 +265,6 @@ class TestCharm(test_utils.CharmTestCase):
             "identity.username": "username",
             "logging.debug": False,
             "monitoring.enable": True,
-            "network.dns-domain": "openstack.local",
             "network.dns-servers": "8.8.8.8",
             "network.enable-gateway": False,
             "network.external-bridge": "br-ex",