build.main

Complexity

Total Complexity

96

Size/Duplication

Total Lines	605
Duplicated Lines	0 %

Test Coverage

Coverage

58.62%

Importance

Changes

0

23 Methods

Rating	Name	Duplication	Size	Complexity
A	Main.get_circuit()	0	13	2
A	Main.setup()	0	23	1
A	Main.delete_circuit()	0	28	4
A	Main.list_circuits()	0	8	2
B	Main.load_evcs()	0	26	8
B	Main.update_schedule()	0	61	6
C	Main._evc_from_dict()	0	40	9
A	Main._find_evc_by_schedule_id()	0	21	5
A	Main.handle_link_up()	0	6	4
A	Main.load_circuits_by_interface()	0	13	4
A	Main.delete_schedule()	0	33	3
A	Main.shutdown()	0	2	1
A	Main.add_to_dict_of_sets()	0	5	2
A	Main.handle_link_down()	0	7	3
A	Main.execute()	0	2	1
A	Main.list_schedules()	0	24	5
B	Main.create_circuit()	0	60	5
A	Main._link_from_dict()	0	20	4
A	Main._uni_from_dict()	0	18	4
A	Main._is_duplicated_evc()	0	14	4
B	Main.update()	0	30	6
A	Main._get_circuits_buffer()	0	13	3
C	Main.create_schedule()	0	89	10

"""Main module of kytos/mef_eline Kytos Network Application.

NApp to provision circuits from user request.
"""
from flask import jsonify, request
from werkzeug.exceptions import BadRequest

from kytos.core import KytosNApp, log, rest
from kytos.core.events import KytosEvent
from kytos.core.helpers import listen_to
from kytos.core.interface import TAG, UNI
from kytos.core.link import Link
from napps.kytos.mef_eline.models import EVC, DynamicPathManager
from napps.kytos.mef_eline.scheduler import CircuitSchedule, Scheduler
from napps.kytos.mef_eline.storehouse import StoreHouse


class Main(KytosNApp):
    """Main class of amlight/mef_eline NApp.

    This class is the entry point for this napp.
    """

    def setup(self):
        """Replace the '__init__' method for the KytosNApp subclass.

        The setup method is automatically called by the controller when your
        application is loaded.

        So, if you have any setup routine, insert it here.
        """
        # object used to scheduler circuit events
        self.sched = Scheduler()

        # object to save and load circuits
        self.storehouse = StoreHouse(self.controller)

        # set the controller that will manager the dynamic paths
        DynamicPathManager.set_controller(self.controller)

        # dictionary of EVCs created. It acts as a circuit buffer.
        # Every create/update/delete must be synced to storehouse.
        self.circuits = {}

        # dictionary of EVCs by interface
        self._circuits_by_interface = {}

    def execute(self):
        """Execute once when the napp is running."""

    def shutdown(self):
        """Execute when your napp is unloaded.

        If you have some cleanup procedure, insert it here.
        """

    @rest('/v2/evc/', methods=['GET'])
    def list_circuits(self):
        """Endpoint to return all circuits stored."""
        circuits = self.storehouse.get_data()
        if not circuits:
            return jsonify({}), 200

        return jsonify(circuits), 200

    @rest('/v2/evc/<circuit_id>', methods=['GET'])
    def get_circuit(self, circuit_id):
        """Endpoint to return a circuit based on id."""
        circuits = self.storehouse.get_data()

        try:
            result = circuits[circuit_id]
            status = 200
        except KeyError:
            result = {'response': f'circuit_id {circuit_id} not found'}
            status = 404

        return jsonify(result), status

    @rest('/v2/evc/', methods=['POST'])
    def create_circuit(self):
        """Try to create a new circuit.

        Firstly, for EVPL: E-Line NApp verifies if UNI_A's requested C-VID and
        UNI_Z's requested C-VID are available from the interfaces' pools. This
        is checked when creating the UNI object.

        Then, E-Line NApp requests a primary and a backup path to the
        Pathfinder NApp using the attributes primary_links and backup_links
        submitted via REST

        # For each link composing paths in #3:
        #  - E-Line NApp requests a S-VID available from the link VLAN pool.
        #  - Using the S-VID obtained, generate abstract flow entries to be
        #    sent to FlowManager

        Push abstract flow entries to FlowManager and FlowManager pushes
        OpenFlow entries to datapaths

        E-Line NApp generates an event to notify all Kytos NApps of a new EVC
        creation

        Finnaly, notify user of the status of its request.
        """
        # Try to create the circuit object
        data = request.get_json()

        if not data:
            return jsonify("Bad request: The request do not have a json."), 400

        try:
            evc = self._evc_from_dict(data)
        except ValueError as exception:
            log.error(exception)
            return jsonify("Bad request: {}".format(exception)), 400

        # verify duplicated evc
        if self._is_duplicated_evc(evc):
            return jsonify("Not Acceptable: This evc already exists."), 409

        # store circuit in dictionary
        self.circuits[evc.id] = evc

        # save circuit
        self.storehouse.save_evc(evc)

        # Schedule the circuit deploy
        self.sched.add(evc)

        # Circuit has no schedule, deploy now
        if not evc.circuit_scheduler:
            evc.deploy()

        # Notify users
        event = KytosEvent(name='kytos.mef_eline.created',
                           content=evc.as_dict())
        self.controller.buffers.app.put(event)

        return jsonify({"circuit_id": evc.id}), 201

    @rest('/v2/evc/<circuit_id>', methods=['PATCH'])
    def update(self, circuit_id):
        """Update a circuit based on payload.

        The EVC required attributes (name, uni_a, uni_z) can't be updated.
        """
        try:
            evc = self.circuits[circuit_id]
            data = request.get_json()
            evc.update(**data)
        except ValueError as exception:
            log.error(exception)
            result = {'response': 'Bad Request: {}'.format(exception)}
            status = 400
        except TypeError:
            result = {'response': 'Content-Type must be application/json'}
            status = 415
        except BadRequest:
            response = 'Bad Request: The request is not a valid JSON.'
            result = {'response': response}
            status = 400
        except KeyError:
            result = {'response': f'circuit_id {circuit_id} not found'}
            status = 404
        else:
            evc.sync()
            result = {evc.id: evc.as_dict()}
            status = 200

        return jsonify(result), status

    @rest('/v2/evc/<circuit_id>', methods=['DELETE'])
    def delete_circuit(self, circuit_id):
        """Remove a circuit.

        First, the flows are removed from the switches, and then the EVC is
        disabled.
        """
        try:
            evc = self.circuits[circuit_id]
        except KeyError:
            result = {'response': f'circuit_id {circuit_id} not found'}
            status = 404
        else:
            log.info(f'Removing {circuit_id}')
            if evc.archived:
                result = {'response': f'Circuit {circuit_id} already removed'}
                status = 404
            else:
                evc.remove_current_flows()
                evc.deactivate()
                evc.disable()
                self.sched.remove(evc)
                evc.archive()
                evc.sync()
                result = {'response': f'Circuit {circuit_id} removed'}
                status = 200

        return jsonify(result), status

    @rest('/v2/evc/schedule', methods=['GET'])
    def list_schedules(self):
        """Endpoint to return all schedules stored for all circuits.

        Return a JSON with the following template:
        [{"schedule_id": <schedule_id>,
         "circuit_id": <circuit_id>,
         "schedule": <schedule object>}]
        """
        circuits = self.storehouse.get_data().values()
        if not circuits:
            return jsonify({}), 200

        result = []
        for circuit in circuits:
            circuit_scheduler = circuit.get("circuit_scheduler")
            if circuit_scheduler:
                for scheduler in circuit_scheduler:
                    value = {"schedule_id": scheduler.get("id"),
                             "circuit_id": circuit.get("id"),
                             "schedule": scheduler}
                    result.append(value)

        return jsonify(result), 200

    @rest('/v2/evc/schedule/', methods=['POST'])
    def create_schedule(self):
        """
        Create a new schedule for a given circuit.

        This service do no check if there are conflicts with another schedule.
        Payload example:
            {
              "circuit_id":"aa:bb:cc",
              "schedule": {
                "date": "2019-08-07T14:52:10.967Z",
                "interval": "string",
                "frequency": "1 * * * *",
                "action": "create"
              }
            }
        """
        try:
            # Try to create the circuit object
            json_data = request.get_json()
            result = ""
            status = 200

            circuit_id = json_data.get("circuit_id")
            schedule_data = json_data.get("schedule")

            if not json_data:
                result = "Bad request: The request does not have a json."
                status = 400
                return jsonify(result), status
            if not circuit_id:
                result = result = "Bad request: Missing circuit_id."
                status = 400
                return jsonify(result), status
            if not schedule_data:
                result = "Bad request: Missing schedule data."
                status = 400
                return jsonify(result), status

            # Get EVC from circuits buffer
            circuits = self._get_circuits_buffer()

            # get the circuit
            evc = circuits.get(circuit_id)

            # get the circuit
            if not evc:
                result = {'response': f'circuit_id {circuit_id} not found'}
                status = 404
                return jsonify(result), status
            # Can not modify circuits deleted and archived
            if evc.archived:
                result = {'response': f'Circuit is archived.'
                                      f'Update is forbidden.'}
                status = 403
                return jsonify(result), status

            # new schedule from dict
            new_schedule = CircuitSchedule.from_dict(schedule_data)

            # If there is no schedule, create the list
            if not evc.circuit_scheduler:
                evc.circuit_scheduler = []

            # Add the new schedule
            evc.circuit_scheduler.append(new_schedule)

            # Add schedule job
            self.sched.add_circuit_job(evc, new_schedule)

            # save circuit to storehouse
            evc.sync()

            result = new_schedule.as_dict()
            status = 201

        except ValueError as exception:
            log.error(exception)
            result = {'response': 'Bad Request: {}'.format(exception)}
            status = 400
        except TypeError:
            result = {'response': 'Content-Type must be application/json'}
            status = 415
        except BadRequest:
            response = 'Bad Request: The request is not a valid JSON.'
            result = {'response': response}
            status = 400

        return jsonify(result), status

    @rest('/v2/evc/schedule/<schedule_id>', methods=['PATCH'])
    def update_schedule(self, schedule_id):
        """Update a schedule.

        Change all attributes from the given schedule from a EVC circuit.
        The schedule ID is preserved as default.
        Payload example:
            {
              "date": "2019-08-07T14:52:10.967Z",
              "interval": "string",
              "frequency": "1 * * *",
              "action": "create"
            }
        """
        try:
            # Try to find a circuit schedule
            evc, found_schedule = self._find_evc_by_schedule_id(schedule_id)

            # Can not modify circuits deleted and archived
            if not found_schedule:
                result = {'response': f'schedule_id {schedule_id} not found'}
                status = 404
                return jsonify(result), status
            if evc.archived:
                result = {'response': f'Circuit is archived.'
                                      f'Update is forbidden.'}
                status = 403
                return jsonify(result), status

            data = request.get_json()

            new_schedule = CircuitSchedule.from_dict(data)
            new_schedule.id = found_schedule.id
            # Remove the old schedule
            evc.circuit_scheduler.remove(found_schedule)
            # Append the modified schedule
            evc.circuit_scheduler.append(new_schedule)

            # Cancel all schedule jobs
            self.sched.cancel_job(found_schedule.id)
            # Add the new circuit schedule
            self.sched.add_circuit_job(evc, new_schedule)
            # Save EVC to the storehouse
            evc.sync()

            result = new_schedule.as_dict()
            status = 200

        except ValueError as exception:
            log.error(exception)
            result = {'response': 'Bad Request: {}'.format(exception)}
            status = 400
        except TypeError:
            result = {'response': 'Content-Type must be application/json'}
            status = 415
        except BadRequest:
            result = {'response':
                      'Bad Request: The request is not a valid JSON.'}
            status = 400

        return jsonify(result), status

    @rest('/v2/evc/schedule/<schedule_id>', methods=['DELETE'])
    def delete_schedule(self, schedule_id):
        """Remove a circuit schedule.

        Remove the Schedule from EVC.
        Remove the Schedule from cron job.
        Save the EVC to the Storehouse.
        """
        evc, found_schedule = self._find_evc_by_schedule_id(schedule_id)

        # Can not modify circuits deleted and archived
        if not found_schedule:
            result = {'response': f'schedule_id {schedule_id} not found'}
            status = 404
            return jsonify(result), status

        if evc.archived:
            result = {'response': f'Circuit is archived. Update is forbidden.'}
            status = 403
            return jsonify(result), status

        # Remove the old schedule
        evc.circuit_scheduler.remove(found_schedule)

        # Cancel all schedule jobs
        self.sched.cancel_job(found_schedule.id)
        # Save EVC to the storehouse
        evc.sync()

        result = "Schedule removed"
        status = 200

        return jsonify(result), status

    def _is_duplicated_evc(self, evc):
        """Verify if the circuit given is duplicated with the stored evcs.

        Args:
            evc (EVC): circuit to be analysed.

        Returns:
            boolean: True if the circuit is duplicated, otherwise False.

        """
        for circuit in self.circuits.values():
            if not circuit.archived and circuit == evc:
                return True
        return False

    @listen_to('kytos/topology.link_up')
    def handle_link_up(self, event):
        """Change circuit when link is up or end_maintenance."""
        for evc in self.circuits.values():
            if evc.is_enabled() and not evc.archived:
                evc.handle_link_up(event.content['link'])

    @listen_to('kytos/topology.link_down')
    def handle_link_down(self, event):
        """Change circuit when link is down or under_mantenance."""
        for evc in self.circuits.values():
            if evc.is_affected_by_link(event.content['link']):
                log.info('handling evc %s' % evc)
                evc.handle_link_down()

    def load_circuits_by_interface(self, circuits):
        """Load circuits in storehouse for in-memory dictionary."""
        for circuit_id, circuit in circuits.items():
            intf_a = circuit['uni_a']['interface_id']
            self.add_to_dict_of_sets(intf_a, circuit_id)
            intf_z = circuit['uni_z']['interface_id']
            self.add_to_dict_of_sets(intf_z, circuit_id)
            for path in ('current_path', 'primary_path', 'backup_path'):
                for link in circuit[path]:
                    intf_a = link['endpoint_a']['id']
                    self.add_to_dict_of_sets(intf_a, circuit_id)
                    intf_b = link['endpoint_b']['id']
                    self.add_to_dict_of_sets(intf_b, circuit_id)

    def add_to_dict_of_sets(self, intf, circuit_id):
        """Add a single item to the dictionary of circuits by interface."""
        if intf not in self._circuits_by_interface:
            self._circuits_by_interface[intf] = set()
        self._circuits_by_interface[intf].add(circuit_id)

    @listen_to('kytos/topology.port.created')
    def load_evcs(self, event):
        """Try to load the unloaded EVCs from storehouse."""
        circuits = self.storehouse.get_data()
        if not self._circuits_by_interface:
            self.load_circuits_by_interface(circuits)

        interface_id = '{}:{}'.format(event.content['switch'],
                                      event.content['port'])

        for circuit_id in self._circuits_by_interface.get(interface_id, []):
            if circuit_id in circuits and circuit_id not in self.circuits:
                try:
                    evc = self._evc_from_dict(circuits[circuit_id])
                except ValueError as exception:
                    log.info(
                        f'Could not load EVC {circuit_id} because {exception}')
                    continue
                log.info(f'Loading EVC {circuit_id}')
                if evc.archived:
                    continue
                if evc.is_enabled():
                    log.info(f'Trying to deploy EVC {circuit_id}')
                    evc.deploy()
                self.circuits[circuit_id] = evc
                self.sched.add(evc)

    def _evc_from_dict(self, evc_dict):
        """Convert some dict values to instance of EVC classes.

        This method will convert: [UNI, Link]
        """
        data = evc_dict.copy()  # Do not modify the original dict

        for attribute, value in data.items():
            # Get multiple attributes.
            # Ex: uni_a, uni_z
            if 'uni' in attribute:
                try:
                    data[attribute] = self._uni_from_dict(value)
                except ValueError as exc:
                    raise ValueError(f'Error creating UNI: {exc}')

            if attribute == 'circuit_scheduler':
                data[attribute] = []
                for schedule in value:
                    data[attribute].append(CircuitSchedule.from_dict(schedule))

            # Get multiple attributes.
            # Ex: primary_links,
            #     backup_links,
            #     current_links_cache,
            #     primary_links_cache,
            #     backup_links_cache
            if 'links' in attribute:
                data[attribute] = [self._link_from_dict(link)
                                   for link in value]

            # Get multiple attributes.
            # Ex: current_path,
            #     primary_path,
            #     backup_path
            if 'path' in attribute and attribute != 'dynamic_backup_path':
                data[attribute] = [self._link_from_dict(link)
                                   for link in value]

        return EVC(self.controller, **data)

    def _uni_from_dict(self, uni_dict):
        """Return a UNI object from python dict."""
        if uni_dict is None:
            return False

        interface_id = uni_dict.get("interface_id")
        interface = self.controller.get_interface_by_id(interface_id)
        if interface is None:
            raise ValueError(f'Could not instantiate interface {interface_id}')

        tag_dict = uni_dict.get("tag")
        tag = TAG.from_dict(tag_dict)
        if tag is False:
            raise ValueError(f'Could not instantiate tag from dict {tag_dict}')

        uni = UNI(interface, tag)

        return uni

    def _link_from_dict(self, link_dict):
        """Return a Link object from python dict."""
        id_a = link_dict.get('endpoint_a').get('id')
        id_b = link_dict.get('endpoint_b').get('id')

        endpoint_a = self.controller.get_interface_by_id(id_a)
        endpoint_b = self.controller.get_interface_by_id(id_b)

        link = Link(endpoint_a, endpoint_b)
        if 'metadata' in link_dict:
            link.extend_metadata(link_dict.get('metadata'))

        s_vlan = link.get_metadata('s_vlan')
        if s_vlan:
            tag = TAG.from_dict(s_vlan)
            if tag is False:
                error_msg = f'Could not instantiate tag from dict {s_vlan}'
                raise ValueError(error_msg)
            link.update_metadata('s_vlan', tag)
        return link

    def _find_evc_by_schedule_id(self, schedule_id):
        """
        Find an EVC and CircuitSchedule based on schedule_id.

        :param schedule_id: Schedule ID
        :return: EVC and Schedule
        """
        circuits = self._get_circuits_buffer()
        found_schedule = None
        evc = None

        # pylint: disable=unused-variable
        for c_id, circuit in circuits.items():
            for schedule in circuit.circuit_scheduler:
                if schedule.id == schedule_id:
                    found_schedule = schedule
                    evc = circuit
                    break
            if found_schedule:
                break
        return evc, found_schedule

    def _get_circuits_buffer(self):
        """
        Return the circuit buffer.

        If the buffer is empty, try to load data from storehouse.
        """
        if not self.circuits:
            # Load storehouse circuits to buffer
            circuits = self.storehouse.get_data()
            for c_id, circuit in circuits.items():
                evc = self._evc_from_dict(circuit)
                self.circuits[c_id] = evc
        return self.circuits