feat: initial version of ietf slice driver added.

src/device/service/drivers/ietf_slice/Constants.py

+# Copyright 2022-2024 ETSI OSG/SDG TeraFlowSDN (TFS) (https://tfs.etsi.org/)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from device.service.driver_api._Driver import (
+    RESOURCE_ENDPOINTS,
+    RESOURCE_INTERFACES,
+    RESOURCE_NETWORK_INSTANCES,
+)
+
+SPECIAL_RESOURCE_MAPPINGS = {
+    RESOURCE_ENDPOINTS: "/endpoints",
+    RESOURCE_INTERFACES: "/interfaces",
+    RESOURCE_NETWORK_INSTANCES: "/net-instances",
+}

src/device/service/drivers/ietf_slice/TfsApiClient.py

+# Copyright 2022-2024 ETSI OSG/SDG TeraFlowSDN (TFS) (https://tfs.etsi.org/)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from typing import Dict, List, Optional
+
+import requests
+from requests.auth import HTTPBasicAuth
+
+from device.service.driver_api.ImportTopologyEnum import ImportTopologyEnum
+
+GET_DEVICES_URL = "{:s}://{:s}:{:d}/tfs-api/devices"
+GET_LINKS_URL = "{:s}://{:s}:{:d}/tfs-api/links"
+IETF_SLICE_URL = "{:s}://{:s}:{:d}/restconf/data/ietf-network-slice-service:ietf-nss"
+TIMEOUT = 30
+
+HTTP_OK_CODES = {
+    200,  # OK
+    201,  # Created
+    202,  # Accepted
+    204,  # No Content
+}
+
+MAPPING_STATUS = {
+    "DEVICEOPERATIONALSTATUS_UNDEFINED": 0,
+    "DEVICEOPERATIONALSTATUS_DISABLED": 1,
+    "DEVICEOPERATIONALSTATUS_ENABLED": 2,
+}
+
+MAPPING_DRIVER = {
+    "DEVICEDRIVER_UNDEFINED": 0,
+    "DEVICEDRIVER_OPENCONFIG": 1,
+    "DEVICEDRIVER_TRANSPORT_API": 2,
+    "DEVICEDRIVER_P4": 3,
+    "DEVICEDRIVER_IETF_NETWORK_TOPOLOGY": 4,
+    "DEVICEDRIVER_ONF_TR_532": 5,
+    "DEVICEDRIVER_XR": 6,
+    "DEVICEDRIVER_IETF_L2VPN": 7,
+    "DEVICEDRIVER_GNMI_OPENCONFIG": 8,
+    "DEVICEDRIVER_OPTICAL_TFS": 9,
+    "DEVICEDRIVER_IETF_ACTN": 10,
+    "DEVICEDRIVER_OC": 11,
+}
+
+MSG_ERROR = "Could not retrieve devices in remote TeraFlowSDN instance({:s}). status_code={:s} reply={:s}"
+
+LOGGER = logging.getLogger(__name__)
+
+
+class TfsApiClient:
+    def __init__(
+        self,
+        address: str,
+        port: int,
+        scheme: str = "http",
+        username: Optional[str] = None,
+        password: Optional[str] = None,
+    ) -> None:
+        self._devices_url = GET_DEVICES_URL.format(scheme, address, port)
+        self._links_url = GET_LINKS_URL.format(scheme, address, port)
+        self._slice_url = IETF_SLICE_URL.format(scheme, address, port)
+        self._auth = None
+        # (
+        #     HTTPBasicAuth(username, password)
+        #     if username is not None and password is not None
+        #     else None
+        # )
+
+    # def get_devices_endpoints(
+    #     self, import_topology: ImportTopologyEnum = ImportTopologyEnum.DEVICES
+    # ) -> List[Dict]:
+    #     LOGGER.debug("[get_devices_endpoints] begin")
+    #     LOGGER.debug(
+    #         "[get_devices_endpoints] import_topology={:s}".format(str(import_topology))
+    #     )
+
+    #     reply = requests.get(self._devices_url, timeout=TIMEOUT, auth=self._auth)
+    #     if reply.status_code not in HTTP_OK_CODES:
+    #         msg = MSG_ERROR.format(
+    #             str(self._devices_url), str(reply.status_code), str(reply)
+    #         )
+    #         LOGGER.error(msg)
+    #         raise Exception(msg)
+
+    #     if import_topology == ImportTopologyEnum.DISABLED:
+    #         raise Exception(
+    #             "Unsupported import_topology mode: {:s}".format(str(import_topology))
+    #         )
+
+    #     result = list()
+    #     for json_device in reply.json()["devices"]:
+    #         device_uuid: str = json_device["device_id"]["device_uuid"]["uuid"]
+    #         device_type: str = json_device["device_type"]
+    #         device_status = json_device["device_operational_status"]
+    #         device_url = "/devices/device[{:s}]".format(device_uuid)
+    #         device_data = {
+    #             "uuid": json_device["device_id"]["device_uuid"]["uuid"],
+    #             "name": json_device["name"],
+    #             "type": device_type,
+    #             "status": MAPPING_STATUS[device_status],
+    #             "drivers": [
+    #                 MAPPING_DRIVER[driver] for driver in json_device["device_drivers"]
+    #             ],
+    #         }
+    #         result.append((device_url, device_data))
+
+    #         for json_endpoint in json_device["device_endpoints"]:
+    #             endpoint_uuid = json_endpoint["endpoint_id"]["endpoint_uuid"]["uuid"]
+    #             endpoint_url = "/endpoints/endpoint[{:s}]".format(endpoint_uuid)
+    #             endpoint_data = {
+    #                 "device_uuid": device_uuid,
+    #                 "uuid": endpoint_uuid,
+    #                 "name": json_endpoint["name"],
+    #                 "type": json_endpoint["endpoint_type"],
+    #             }
+    #             result.append((endpoint_url, endpoint_data))
+
+    #     if import_topology == ImportTopologyEnum.DEVICES:
+    #         LOGGER.debug("[get_devices_endpoints] devices only; returning")
+    #         return result
+
+    #     reply = requests.get(self._links_url, timeout=TIMEOUT, auth=self._auth)
+    #     if reply.status_code not in HTTP_OK_CODES:
+    #         msg = MSG_ERROR.format(
+    #             str(self._links_url), str(reply.status_code), str(reply)
+    #         )
+    #         LOGGER.error(msg)
+    #         raise Exception(msg)
+
+    #     for json_link in reply.json()["links"]:
+    #         link_uuid: str = json_link["link_id"]["link_uuid"]["uuid"]
+    #         link_url = "/links/link[{:s}]".format(link_uuid)
+    #         link_endpoint_ids = [
+    #             (
+    #                 json_endpoint_id["device_id"]["device_uuid"]["uuid"],
+    #                 json_endpoint_id["endpoint_uuid"]["uuid"],
+    #             )
+    #             for json_endpoint_id in json_link["link_endpoint_ids"]
+    #         ]
+    #         link_data = {
+    #             "uuid": json_link["link_id"]["link_uuid"]["uuid"],
+    #             "name": json_link["name"],
+    #             "endpoints": link_endpoint_ids,
+    #         }
+    #         result.append((link_url, link_data))
+
+    #     LOGGER.debug("[get_devices_endpoints] topology; returning")
+    # #     return resu
+
+    def create_slice(self, slice_data: dict) -> None:
+        try:
+            requests.post(self._slice_url, json=slice_data)
+        except requests.exceptions.ConnectionError:
+            raise Exception("faild to send post request to TFS L3VPN NBI")
+
+    def delete_slice(self, slice_uuid: str) -> None:
+        url = self.__url + f"/vpn-service={slice_uuid}"
+        try:
+            requests.delete(url, auth=self._auth)
+        except requests.exceptions.ConnectionError:
+            raise Exception("faild to send delete request to TFS L3VPN NBI")

src/device/service/drivers/ietf_slice/Tools.py

+# Copyright 2022-2024 ETSI OSG/SDG TeraFlowSDN (TFS) (https://tfs.etsi.org/)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+from typing import Any, Dict, Optional, Tuple, TypedDict
+
+import requests
+
+from common.proto.kpi_sample_types_pb2 import KpiSampleType
+from common.type_checkers.Checkers import chk_attribute, chk_string, chk_type
+from device.service.driver_api._Driver import RESOURCE_ENDPOINTS
+
+from .Constants import SPECIAL_RESOURCE_MAPPINGS
+
+LOGGER = logging.getLogger(__name__)
+
+
+def service_exists(wim_url: str, auth, service_uuid: str) -> bool:
+    try:
+        get_connectivity_service(wim_url, auth, service_uuid)
+        return True
+    except:  # pylint: disable=bare-except
+        return False
+
+
+def get_all_active_connectivity_services(wim_url: str, auth):
+    try:
+        LOGGER.info("Sending get all connectivity services")
+        servicepoint = f"{wim_url}/restconf/data/ietf-l3vpn-svc:l3vpn-svc/vpn-services"
+        response = requests.get(servicepoint, auth=auth)
+
+        if response.status_code != requests.codes.ok:
+            raise Exception(
+                "Unable to get all connectivity services",
+                http_code=response.status_code,
+            )
+
+        return response
+    except requests.exceptions.ConnectionError:
+        raise Exception("Request Timeout", http_code=408)
+
+
+def get_connectivity_service(wim_url, auth, service_uuid):
+    try:
+        LOGGER.info("Sending get connectivity service")
+        servicepoint = f"{wim_url}/restconf/data/ietf-l3vpn-svc:l3vpn-svc/vpn-services/vpn-service={service_uuid}"
+
+        response = requests.get(servicepoint)
+
+        if response.status_code != requests.codes.ok:
+            raise Exception(
+                "Unable to get connectivity service{:s}".format(str(service_uuid)),
+                http_code=response.status_code,
+            )
+
+        return response
+    except requests.exceptions.ConnectionError:
+        raise Exception("Request Timeout", http_code=408)
+
+
+def create_slice_datamodel(resource_value: dict) -> dict:
+    src_node_id: str = resource_value["src_node_id"]
+    src_mgmt_ip_address: str = resource_value["src_mgmt_ip_address"]
+    src_ac_node_id: str = resource_value["src_ac_node_id"]
+    src_ac_ep_id: str = resource_value["src_ac_ep_id"]
+    src_vlan: str = resource_value["src_vlan"]
+
+    dst_node_id: str = resource_value["dst_node_id"]
+    dst_mgmt_ip_address: str = resource_value["dst_mgmt_ip_address"]
+    dst_ac_node_id: str = resource_value["dst_ac_node_id"]
+    dst_ac_ep_id: str = resource_value["dst_ac_ep_id"]
+    dst_vlan: str = resource_value["dst_vlan"]
+
+    slice_id: str = resource_value["slice_id"]
+    delay: str = resource_value["delay"]
+    bandwidth: str = resource_value["bandwidth"]
+    packet_loss: str = resource_value["packet_loss"]
+
+    sdps = [
+        {
+            "id": "1",
+            "node-id": src_node_id,
+            "sdp-ip-address": [src_mgmt_ip_address],
+            "service-match-criteria": {
+                "match-criterion": [
+                    {
+                        "index": 1,
+                        "match-type": [
+                            {
+                                "type": "ietf-network-slice-service:vlan",
+                                "value": [src_vlan],
+                            },
+                        ],
+                        "target-connection-group-id": "line1",
+                    }
+                ]
+            },
+            "attachment-circuits": {
+                "attachment-circuit": [
+                    {
+                        "id": "0",
+                        "description": "dsc",
+                        "ac-node-id": src_ac_node_id,
+                        "ac-tp-id": src_ac_ep_id,
+                    }
+                ]
+            },
+        },
+        {
+            "id": "2",
+            "node-id": dst_node_id,
+            "sdp-ip-address": [dst_mgmt_ip_address],
+            "service-match-criteria": {
+                "match-criterion": [
+                    {
+                        "index": 1,
+                        "match-type": [
+                            {
+                                "type": "ietf-network-slice-service:vlan",
+                                "value": [dst_vlan],
+                            },
+                        ],
+                        "target-connection-group-id": "line1",
+                    }
+                ]
+            },
+            "attachment-circuits": {
+                "attachment-circuit": [
+                    {
+                        "id": "0",
+                        "description": "dsc",
+                        "ac-node-id": dst_ac_node_id,
+                        "ac-tp-id": dst_ac_ep_id,
+                    }
+                ]
+            },
+        },
+    ]
+
+    connection_groups = [
+        {
+            "id": "line1",
+            "connectivity-type": "point-to-point",
+            "connectivity-construct": [
+                {
+                    "id": 1,
+                    "p2mp-sender-sdp": "1",
+                    "p2mp-receiver-sdp": ["2"],
+                    "service-slo-sle-policy": {
+                        "slo-policy": {
+                            "metric-bound": [
+                                {
+                                    "metric-type": "ietf-network-slice-service:one-way-delay-maximum",
+                                    "metric-unit": "milliseconds",
+                                    "bound": delay,
+                                },
+                                {
+                                    "metric-type": "ietf-network-slice-service:one-way-bandwidth",
+                                    "metric-unit": "Mbps",
+                                    "bound": bandwidth,
+                                },
+                                {
+                                    "metric-type": "ietf-network-slice-service:two-way-packet-loss",
+                                    "metric-unit": "percentage",
+                                    "percentile-value": packet_loss,
+                                },
+                            ]
+                        }
+                    },
+                },
+                {
+                    "id": 2,
+                    "p2mp-sender-sdp": "2",
+                    "p2mp-receiver-sdp": ["1"],
+                    "service-slo-sle-policy": {
+                        "slo-policy": {
+                            "metric-bound": [
+                                {
+                                    "metric-type": "ietf-network-slice-service:one-way-delay-maximum",
+                                    "metric-unit": "milliseconds",
+                                    "bound": delay,
+                                },
+                                {
+                                    "metric-type": "ietf-network-slice-service:one-way-bandwidth",
+                                    "metric-unit": "Mbps",
+                                    "bound": bandwidth,
+                                },
+                                {
+                                    "metric-type": "ietf-network-slice-service:two-way-packet-loss",
+                                    "metric-unit": "percentage",
+                                    "percentile-value": packet_loss,
+                                },
+                            ]
+                        }
+                    },
+                },
+            ],
+        }
+    ]
+
+    slice_service = {
+        "id": slice_id,
+        "description": "dsc",
+        "sdps": {"sdp": sdps},
+        "connection-groups": {"connection-group": connection_groups},
+    }
+    slice_data_model = {"network-slice-services": {"slice-service": [slice_service]}}
+    return slice_data_model
+
+
+def process_optional_string_field(
+    endpoint_data: Dict[str, Any],
+    field_name: str,
+    endpoint_resource_value: Dict[str, Any],
+) -> None:
+    field_value = chk_attribute(
+        field_name, endpoint_data, "endpoint_data", default=None
+    )
+    if field_value is None:
+        return
+    chk_string("endpoint_data.{:s}".format(field_name), field_value)
+    if len(field_value) > 0:
+        endpoint_resource_value[field_name] = field_value
+
+
+def compose_resource_endpoint(
+    endpoint_data: Dict[str, Any],
+) -> Optional[Tuple[str, Dict]]:
+    try:
+        # Check type of endpoint_data
+        chk_type("endpoint_data", endpoint_data, dict)
+
+        # Check endpoint UUID (mandatory)
+        endpoint_uuid = chk_attribute("uuid", endpoint_data, "endpoint_data")
+        chk_string("endpoint_data.uuid", endpoint_uuid, min_length=1)
+        endpoint_resource_path = SPECIAL_RESOURCE_MAPPINGS.get(RESOURCE_ENDPOINTS)
+        endpoint_resource_key = "{:s}/endpoint[{:s}]".format(
+            endpoint_resource_path, endpoint_uuid
+        )
+        endpoint_resource_value = {"uuid": endpoint_uuid}
+
+        # Check endpoint optional string fields
+        process_optional_string_field(endpoint_data, "name", endpoint_resource_value)
+        process_optional_string_field(
+            endpoint_data, "site_location", endpoint_resource_value
+        )
+        process_optional_string_field(endpoint_data, "ce-ip", endpoint_resource_value)
+        process_optional_string_field(
+            endpoint_data, "address_ip", endpoint_resource_value
+        )
+        process_optional_string_field(
+            endpoint_data, "address_prefix", endpoint_resource_value
+        )
+        process_optional_string_field(endpoint_data, "mtu", endpoint_resource_value)
+        process_optional_string_field(
+            endpoint_data, "ipv4_lan_prefixes", endpoint_resource_value
+        )
+        process_optional_string_field(endpoint_data, "type", endpoint_resource_value)
+        process_optional_string_field(
+            endpoint_data, "context_uuid", endpoint_resource_value
+        )
+        process_optional_string_field(
+            endpoint_data, "topology_uuid", endpoint_resource_value
+        )
+
+        # Check endpoint sample types (optional)
+        endpoint_sample_types = chk_attribute(
+            "sample_types", endpoint_data, "endpoint_data", default=[]
+        )
+        chk_type("endpoint_data.sample_types", endpoint_sample_types, list)
+        sample_types = {}
+        sample_type_errors = []
+        for i, endpoint_sample_type in enumerate(endpoint_sample_types):
+            field_name = "endpoint_data.sample_types[{:d}]".format(i)
+            try:
+                chk_type(field_name, endpoint_sample_type, (int, str))
+                if isinstance(endpoint_sample_type, int):
+                    metric_name = KpiSampleType.Name(endpoint_sample_type)
+                    metric_id = endpoint_sample_type
+                elif isinstance(endpoint_sample_type, str):
+                    metric_id = KpiSampleType.Value(endpoint_sample_type)
+                    metric_name = endpoint_sample_type
+                else:
+                    str_type = str(type(endpoint_sample_type))
+                    raise Exception("Bad format: {:s}".format(str_type))  # pylint: disable=broad-exception-raised
+            except Exception as e:  # pylint: disable=broad-exception-caught
+                MSG = "Unsupported {:s}({:s}) : {:s}"
+                sample_type_errors.append(
+                    MSG.format(field_name, str(endpoint_sample_type), str(e))
+                )
+
+            metric_name = metric_name.lower().replace("kpisampletype_", "")
+            monitoring_resource_key = "{:s}/state/{:s}".format(
+                endpoint_resource_key, metric_name
+            )
+            sample_types[metric_id] = monitoring_resource_key
+
+        if len(sample_type_errors) > 0:
+            # pylint: disable=broad-exception-raised
+            raise Exception(
+                "Malformed Sample Types:\n{:s}".format("\n".join(sample_type_errors))
+            )
+
+        if len(sample_types) > 0:
+            endpoint_resource_value["sample_types"] = sample_types
+
+        if "site_location" in endpoint_data:
+            endpoint_resource_value["site_location"] = endpoint_data["site_location"]
+
+        if "ce-ip" in endpoint_data:
+            endpoint_resource_value["ce-ip"] = endpoint_data["ce-ip"]
+
+        if "address_ip" in endpoint_data:
+            endpoint_resource_value["address_ip"] = endpoint_data["address_ip"]
+
+        if "address_prefix" in endpoint_data:
+            endpoint_resource_value["address_prefix"] = endpoint_data["address_prefix"]
+
+        if "mtu" in endpoint_data:
+            endpoint_resource_value["mtu"] = endpoint_data["mtu"]
+
+        if "ipv4_lan_prefixes" in endpoint_data:
+            endpoint_resource_value["ipv4_lan_prefixes"] = endpoint_data[
+                "ipv4_lan_prefixes"
+            ]
+
+        return endpoint_resource_key, endpoint_resource_value
+    except:  # pylint: disable=bare-except
+        LOGGER.exception("Problem composing endpoint({:s})".format(str(endpoint_data)))
+        return None

src/device/service/drivers/ietf_slice/__init__.py

+# Copyright 2022-2024 ETSI OSG/SDG TeraFlowSDN (TFS) (https://tfs.etsi.org/)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.

src/device/service/drivers/ietf_slice/driver.py

+# Copyright 2022-2024 ETSI OSG/SDG TeraFlowSDN (TFS) (https://tfs.etsi.org/)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import json
+import logging
+import re
+import threading
+from typing import Any, Iterator, List, Optional, Tuple, Union
+
+import anytree
+import requests
+from requests.auth import HTTPBasicAuth
+
+from common.method_wrappers.Decorator import MetricsPool, metered_subclass_method
+from common.type_checkers.Checkers import chk_length, chk_string, chk_type
+from device.service.driver_api._Driver import (
+    RESOURCE_ENDPOINTS,
+    RESOURCE_SERVICES,
+    _Driver,
+)
+from device.service.driver_api.AnyTreeTools import (
+    TreeNode,
+    dump_subtree,
+    get_subnode,
+    set_subnode_value,
+)
+from device.service.driver_api.ImportTopologyEnum import (
+    ImportTopologyEnum,
+    get_import_topology,
+)
+
+from .Constants import SPECIAL_RESOURCE_MAPPINGS
+from .TfsApiClient import TfsApiClient
+from .Tools import (
+    compose_resource_endpoint,
+    service_exists,
+)
+
+LOGGER = logging.getLogger(__name__)
+
+
+ALL_RESOURCE_KEYS = [
+    RESOURCE_ENDPOINTS,
+    RESOURCE_SERVICES,
+]
+
+RE_IETF_SLICE_DATA = re.compile(r"^\/service\[[^\]]+\]\/IETFSlice$")
+RE_IETF_SLICE_OPERATION = re.compile(r"^\/service\[[^\]]+\]\/IETFSlice\/operation$")
+
+DRIVER_NAME = "ietf_slice"
+METRICS_POOL = MetricsPool("Device", "Driver", labels={"driver": DRIVER_NAME})
+
+
+class IetfSliceDriver(_Driver):
+    def __init__(self, address: str, port: str, **settings) -> None:
+        super().__init__(DRIVER_NAME, address, int(port), **settings)
+        self.__lock = threading.Lock()
+        self.__started = threading.Event()
+        self.__terminate = threading.Event()
+        self.__running = TreeNode(".")
+        scheme = self.settings.get("scheme", "http")
+        username = self.settings.get("username")
+        password = self.settings.get("password")
+        self.tac = TfsApiClient(
+            self.address,
+            self.port,
+            scheme=scheme,
+            username=username,
+            password=password,
+        )
+        self.__auth = None
+        # (
+        #     HTTPBasicAuth(username, password)
+        #     if username is not None and password is not None
+        #     else None
+        # )
+        self.__tfs_nbi_root = "{:s}://{:s}:{:d}".format(
+            scheme, self.address, int(self.port)
+        )
+        self.__timeout = int(self.settings.get("timeout", 120))
+        self.__import_topology = get_import_topology(
+            self.settings, default=ImportTopologyEnum.DEVICES
+        )
+        endpoints = self.settings.get("endpoints", [])
+        endpoint_resources = []
+        for endpoint in endpoints:
+            endpoint_resource = compose_resource_endpoint(endpoint)
+            if endpoint_resource is None:
+                continue
+            endpoint_resources.append(endpoint_resource)
+        self._set_initial_config(endpoint_resources)
+
+    def _set_initial_config(
+        self, resources: List[Tuple[str, Any]]
+    ) -> List[Union[bool, Exception]]:
+        chk_type("resources", resources, list)
+        if len(resources) == 0:
+            return []
+        results = []
+        resolver = anytree.Resolver(pathattr="name")
+        with self.__lock:
+            for i, resource in enumerate(resources):
+                str_resource_name = "resources[#{:d}]".format(i)
+                try:
+                    chk_type(str_resource_name, resource, (list, tuple))
+                    chk_length(str_resource_name, resource, min_length=2, max_length=2)
+                    resource_key, resource_value = resource
+                    chk_string(str_resource_name, resource_key, allow_empty=False)
+                    resource_path = resource_key.split("/")
+                except Exception as e:  # pylint: disable=broad-except
+                    LOGGER.exception(
+                        "Exception validating {:s}: {:s}".format(
+                            str_resource_name, str(resource_key)
+                        )
+                    )
+                    results.append(e)  # if validation fails, store the exception
+                    continue
+
+                try:
+                    resource_value = json.loads(resource_value)
+                except:  # pylint: disable=bare-except
+                    pass
+
+                set_subnode_value(
+                    resolver, self.__running, resource_path, resource_value
+                )
+
+                results.append(True)
+        return results
+
+    def Connect(self) -> bool:
+        url = self.__tfs_nbi_root + "/restconf/data/ietf-network-slice-service:ietf-nss"
+        with self.__lock:
+            if self.__started.is_set():
+                return True
+            try:
+                # requests.get(url, timeout=self.__timeout, auth=self.__auth)
+                ...
+            except requests.exceptions.Timeout:
+                LOGGER.exception("Timeout connecting {:s}".format(url))
+                return False
+            except Exception:  # pylint: disable=broad-except
+                LOGGER.exception("Exception connecting {:s}".format(url))
+                return False
+            else:
+                self.__started.set()
+                return True
+
+    def Disconnect(self) -> bool:
+        with self.__lock:
+            self.__terminate.set()
+            return True
+
+    @metered_subclass_method(METRICS_POOL)
+    def GetInitialConfig(self) -> List[Tuple[str, Any]]:
+        with self.__lock:
+            return []
+
+    @metered_subclass_method(METRICS_POOL)
+    def GetConfig(
+        self, resource_keys: List[str] = []
+    ) -> List[Tuple[str, Union[Any, None, Exception]]]:
+        chk_type("resources", resource_keys, list)
+        with self.__lock:
+            if len(resource_keys) == 0:
+                return dump_subtree(self.__running)
+            results = []
+            resolver = anytree.Resolver(pathattr="name")
+            for i, resource_key in enumerate(resource_keys):
+                str_resource_name = "resource_key[#{:d}]".format(i)
+                try:
+                    chk_string(str_resource_name, resource_key, allow_empty=False)
+                    resource_key = SPECIAL_RESOURCE_MAPPINGS.get(
+                        resource_key, resource_key
+                    )
+                    resource_path = resource_key.split("/")
+                except Exception as e:  # pylint: disable=broad-except
+                    LOGGER.exception(
+                        "Exception validating {:s}: {:s}".format(
+                            str_resource_name, str(resource_key)
+                        )
+                    )
+                    results.append(
+                        (resource_key, e)
+                    )  # if validation fails, store the exception
+                    continue
+
+                resource_node = get_subnode(
+                    resolver, self.__running, resource_path, default=None
+                )
+                # if not found, resource_node is None
+                if resource_node is None:
+                    continue
+                results.extend(dump_subtree(resource_node))
+            return results
+        return results
+
+    @metered_subclass_method(METRICS_POOL)
+    def SetConfig(
+        self, resources: List[Tuple[str, Any]]
+    ) -> List[Union[bool, Exception]]:
+        results = []
+        if len(resources) == 0:
+            return results
+        with self.__lock:
+            for resource in resources:
+                resource_key, resource_value = resource
+                if RE_IETF_SLICE_OPERATION.match(resource_key):
+                    operation_type = json.loads(resource_value)["type"]
+                    results.append((resource_key, True))
+                    break
+            else:
+                raise Exception("operation type not found in resources")
+            for resource in resources:
+                LOGGER.info("resource = {:s}".format(str(resource)))
+                resource_key, resource_value = resource
+                if not RE_IETF_SLICE_DATA.match(resource_key):
+                    continue
+                try:
+                    resource_value = json.loads(resource_value)
+
+                    if operation_type == "create":
+                        # create the underlying service
+                        # self.tac.create_slice(resource_value)
+                        ...
+                    elif (
+                        len(
+                            resource_value["network-slice-services"]["slice-service"][
+                                0
+                            ]["connection-groups"]["connection-group"]
+                        )
+                        == 0
+                        and operation_type == "update"
+                    ):
+                        # Remove the IP transport service
+                        # self.tac.remove_slice(service_uuid)
+                        ...
+                    elif operation_type == "update":
+                        # update the underlying service bandwidth
+                        # self.tac.update_slice(resource_value)
+                        ...
+                    results.append((resource_key, True))
+                except Exception as e:  # pylint: disable=broad-except
+                    LOGGER.exception(
+                        "Unhandled error processing resource_key({:s})".format(
+                            str(resource_key)
+                        )
+                    )
+                    results.append((resource_key, e))
+        return results
+
+    @metered_subclass_method(METRICS_POOL)
+    def DeleteConfig(
+        self, resources: List[Tuple[str, Any]]
+    ) -> List[Union[bool, Exception]]:
+        results = []
+        if len(resources) == 0:
+            return results
+        with self.__lock:
+            for resource in resources:
+                LOGGER.info("resource = {:s}".format(str(resource)))
+                resource_key, resource_value = resource
+                try:
+                    # resource_value = json.loads(resource_value)
+                    # service_uuid = resource_value["uuid"]
+                    # if service_exists(self.__tfs_nbi_root, self.__auth, service_uuid):
+                    #     self.tac.delete_slice(service_uuid)
+                    results.append((resource_key, True))
+                except Exception as e:  # pylint: disable=broad-except
+                    LOGGER.exception(
+                        "Unhandled error processing resource_key({:s})".format(
+                            str(resource_key)
+                        )
+                    )
+                    results.append((resource_key, e))
+        return results
+
+    @metered_subclass_method(METRICS_POOL)
+    def SubscribeState(
+        self, subscriptions: List[Tuple[str, float, float]]
+    ) -> List[Union[bool, Exception]]:
+        # TODO: IETF Slice does not support monitoring by now
+        return [False for _ in subscriptions]
+
+    @metered_subclass_method(METRICS_POOL)
+    def UnsubscribeState(
+        self, subscriptions: List[Tuple[str, float, float]]
+    ) -> List[Union[bool, Exception]]:
+        # TODO: IETF Slice does not support monitoring by now
+        return [False for _ in subscriptions]
+
+    def GetState(
+        self, blocking=False, terminate: Optional[threading.Event] = None
+    ) -> Iterator[Tuple[float, str, Any]]:
+        # TODO: IETF Slice does not support monitoring by now
+        return []