build.main.Main._add_flow_mod_sent() - Code Metrics - Inspection of "Added flow persistence" - kytos/flow_manager - Measure and Improve Code Quality continuously with Scrutinizer

Test Failed

Pull Request — master (#90)

by Carlos

created 2020-11-24 13:16 UTC

build.main.Main._add_flow_mod_sent() A

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	5
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	0
CRAP Score	6

Importance

Changes

Metric	Value
cc	2
eloc	4
nop	4
dl	0
loc	5
rs	10
c	0
b	0
f	0
ccs	0
cts	0
cp	0
crap	6

"""kytos/flow_manager NApp installs, lists and deletes switch flows."""
from collections import OrderedDict

from flask import jsonify, request

from kytos.core import KytosEvent, KytosNApp, log, rest
from kytos.core.helpers import listen_to
from napps.kytos.flow_manager.storehouse import StoreHouse
from napps.kytos.of_core.flow import FlowFactory

from .exceptions import InvalidCommandError
from .settings import FLOWS_DICT_MAX_SIZE


class Main(KytosNApp):
    """Main class to be used by Kytos controller."""

    def setup(self):
        """Replace the 'init' method for the KytosApp subclass.

        The setup method is automatically called by the run method.
        Users shouldn't call this method directly.
        """
        log.debug("flow-manager starting")
        self._flow_mods_sent = OrderedDict()
        self._flow_mods_sent_max_size = FLOWS_DICT_MAX_SIZE

        # Storehouse client to save and restore flow data:
        self.storehouse = StoreHouse(self.controller)

        # Format of stored flow data:
        # {'flow_persistence': {'dpid_str': {'flow_list': [
        #                                     {'command': '<add|delete>',
        #                                      'flow': {flow_dict}}]}}}
        self.stored_flows = {}
        self.resent_flows = set()

    def execute(self):
        """Run once on NApp 'start' or in a loop.

        The execute method is called by the run method of KytosNApp class.
        Users shouldn't call this method directly.
        """
        self._load_flows()

    def shutdown(self):
        """Shutdown routine of the NApp."""
        log.debug("flow-manager stopping")

    @listen_to('kytos/topology.port.created')
    def resend_stored_flows(self, event):
        """Resend stored Flows."""
        dpid = str(event.content['switch'])
        switch = self.controller.get_switch_by_dpid(dpid)
        # This can be a problem because this code is running a thread
        if dpid in self.resent_flows:
            log.info(f'Flow already resended to Switch {dpid}')
            return
        if dpid in self.stored_flows:
            flow_list = self.stored_flows[dpid]['flow_list']
            for flow in flow_list:
                command = flow['command']
                flows_dict = {"flows": [flow['flow']]}
                self._install_flows(command, flows_dict, [switch])
            self.resent_flows.add(dpid)
            log.info(f'Flows resent to Switch {dpid}')

    # pylint: disable=attribute-defined-outside-init
    def _load_flows(self):
        """Load stored flows."""
        try:
            data = self.storehouse.get_data()['flow_persistence']
            if 'id' in data:
                del data['id']
            self.stored_flows = data

        except KeyError as error:
            log.debug(f'There are no flows to load: {error}')
        else:
            log.info('Flows loaded.')

    @staticmethod
    def _generate_match_fields(flow):
        """Generate flow match fields."""
        match_fields = {}
        for field in flow:
            if 'priority' in field:
                match_fields['priority'] = flow['priority']
            if 'cookie' in field:
                match_fields['cookie'] = flow['cookie']
            if 'match' in field:
                match_fields.update(flow['match'])
        return match_fields

    def _is_equal_flows(self, flow_1, flow_2):
        """Check if two flows are equal."""
        flow_1_match_fields = self._generate_match_fields(flow_1)
        flow_2_match_fields = self._generate_match_fields(flow_2)
        if flow_1_match_fields == flow_2_match_fields:
            return True
        return False

    def _store_changed_flows(self, command, flow, switch):
        """Store changed flows.

        Args:
            command: Flow command to be installed
            flow: Flows to be stored
            switch: Switch target
        """
        stored_flows_box = self.stored_flows.copy()
        # if the flow has a destination dpid it can be stored.
        if not switch:
            log.info('The Flow cannot be stored, the destination switch '
                     f'have not been specified: {switch}')
            return

        installed_flow = {}
        flow_list = []
        installed_flow['command'] = command
        installed_flow['flow'] = flow

        serializer = FlowFactory.get_class(switch)
        installed_flow_obj = serializer.from_dict(flow, switch)

        if switch.id not in stored_flows_box:
            # Switch not stored, add to box.
            flow_list.append(installed_flow)
            stored_flows_box[switch.id] = {"flow_list": flow_list}
        else:
            stored_flows = stored_flows_box[switch.id].get('flow_list', [])
            # Check if flow already stored
            for stored_flow in stored_flows:
                stored_flow_obj = serializer.from_dict(stored_flow['flow'],
                                                       switch)
                if installed_flow_obj.id == stored_flow_obj.id:
                    if stored_flow['command'] == installed_flow['command']:
                        log.debug('Data already stored.')
                        return
                    # Flow with inconsistency in "command" fields : Remove the
                    # old instruction. This happens when there is a stored
                    # instruction to install the flow, but the new instruction
                    # is to remove it. In this case, the old instruction is
                    # removed and the new one is stored.
                    stored_flow['command'] = installed_flow.get('command')
                    stored_flows.remove(stored_flow)
                    break

            stored_flows.append(installed_flow)
            stored_flows_box[switch.id]['flow_list'] = stored_flows

        stored_flows_box['id'] = 'flow_persistence'
        self.storehouse.save_flow(stored_flows_box)
        del stored_flows_box['id']
        self.stored_flows = stored_flows_box.copy()

    @rest('v2/flows')
    @rest('v2/flows/<dpid>')
    def list(self, dpid=None):
        """Retrieve all flows from a switch identified by dpid.

        If no dpid is specified, return all flows from all switches.
        """
        if dpid is None:
            switches = self.controller.switches.values()
        else:
            switches = [self.controller.get_switch_by_dpid(dpid)]

        switch_flows = {}

        for switch in switches:
            flows_dict = [flow.as_dict() for flow in switch.flows]
            switch_flows[switch.dpid] = {'flows': flows_dict}

        return jsonify(switch_flows)

    @rest('v2/flows', methods=['POST'])
    @rest('v2/flows/<dpid>', methods=['POST'])
    def add(self, dpid=None):
        """Install new flows in the switch identified by dpid.

        If no dpid is specified, install flows in all switches.
        """
        return self._send_flow_mods_from_request(dpid, "add")

    @rest('v2/delete', methods=['POST'])
    @rest('v2/delete/<dpid>', methods=['POST'])
    @rest('v2/flows', methods=['DELETE'])
    @rest('v2/flows/<dpid>', methods=['DELETE'])
    def delete(self, dpid=None):
        """Delete existing flows in the switch identified by dpid.

        If no dpid is specified, delete flows from all switches.
        """
        return self._send_flow_mods_from_request(dpid, "delete")

    def _get_all_switches_enabled(self):
        """Get a list of all switches enabled."""
        switches = self.controller.switches.values()
        return [switch for switch in switches if switch.is_enabled()]

    def _send_flow_mods_from_request(self, dpid, command, flows_dict=None):
        """Install FlowsMods from request."""
        if flows_dict is None:
            flows_dict = request.get_json()
            if flows_dict is None:
                return jsonify({"response": 'flows dict is none.'}), 404

        if dpid:
            switch = self.controller.get_switch_by_dpid(dpid)
            if not switch:
                return jsonify({"response": 'dpid not found.'}), 404
            elif switch.is_enabled() is False:
                return jsonify({"response": 'switch is disabled.'}), 404
            else:
                self._install_flows(command, flows_dict, [switch])
        else:
            self._install_flows(command, flows_dict,
                                self._get_all_switches_enabled())

        return jsonify({"response": "FlowMod Messages Sent"})

    def _install_flows(self, command, flows_dict, switches=[]):
        """Execute all procedures to install flows in the switches.

        Args:
            command: Flow command to be installed
            flows_dict: Dictionary with flows to be installed in the switches.
            switches: A list of switches
        """
        for switch in switches:
            serializer = FlowFactory.get_class(switch)
            flows = flows_dict.get('flows', [])
            for flow_dict in flows:
                flow = serializer.from_dict(flow_dict, switch)
                if command == "delete":
                    flow_mod = flow.as_of_delete_flow_mod()
                elif command == "add":
                    flow_mod = flow.as_of_add_flow_mod()
                else:
                    raise InvalidCommandError
                self._send_flow_mod(flow.switch, flow_mod)
                self._add_flow_mod_sent(flow_mod.header.xid, flow, command)

                self._send_napp_event(switch, flow, command)
                self._store_changed_flows(command, flow_dict, switch)

    def _add_flow_mod_sent(self, xid, flow, command):
        """Add the flow mod to the list of flow mods sent."""
        if len(self._flow_mods_sent) >= self._flow_mods_sent_max_size:
            self._flow_mods_sent.popitem(last=False)
        self._flow_mods_sent[xid] = (flow, command)

    def _send_flow_mod(self, switch, flow_mod):
        event_name = 'kytos/flow_manager.messages.out.ofpt_flow_mod'

        content = {'destination': switch.connection,
                   'message': flow_mod}

        event = KytosEvent(name=event_name, content=content)
        self.controller.buffers.msg_out.put(event)

    def _send_napp_event(self, switch, flow, command, **kwargs):
        """Send an Event to other apps informing about a FlowMod."""
        if command == 'add':
            name = 'kytos/flow_manager.flow.added'
        elif command == 'delete':
            name = 'kytos/flow_manager.flow.removed'
        elif command == 'error':
            name = 'kytos/flow_manager.flow.error'
        else:
            raise InvalidCommandError
        content = {'datapath': switch,
                   'flow': flow}
        content.update(kwargs)
        event_app = KytosEvent(name, content)
        self.controller.buffers.app.put(event_app)

    @listen_to('.*.of_core.*.ofpt_error')
    def handle_errors(self, event):
        """Receive OpenFlow error and send a event.

        The event is sent only if the error is related to a request made
        by flow_manager.
        """
        xid = event.content["message"].header.xid.value
        error_type = event.content["message"].error_type
        error_code = event.content["message"].code
        try:
            flow, error_command = self._flow_mods_sent[xid]
        except KeyError:
            pass
        else:
            self._send_napp_event(flow.switch, flow, 'error',
                                  error_command=error_command,
                                  error_type=error_type, error_code=error_code)


1		"""kytos/flow_manager NApp installs, lists and deletes switch flows."""
2	1	from collections import OrderedDict
3
4	1	from flask import jsonify, request
5
6	1	from kytos.core import KytosEvent, KytosNApp, log, rest
7	1	from kytos.core.helpers import listen_to
8	1	from napps.kytos.flow_manager.storehouse import StoreHouse
9		from napps.kytos.of_core.flow import FlowFactory
10	1
11	1	from .exceptions import InvalidCommandError
12		from .settings import FLOWS_DICT_MAX_SIZE
13
14	1
15		class Main(KytosNApp):
16		"""Main class to be used by Kytos controller."""
17	1
18		def setup(self):
19		"""Replace the 'init' method for the KytosApp subclass.
20
21		The setup method is automatically called by the run method.
22		Users shouldn't call this method directly.
23	1	"""
24	1	log.debug("flow-manager starting")
25	1	self._flow_mods_sent = OrderedDict()
26		self._flow_mods_sent_max_size = FLOWS_DICT_MAX_SIZE
27	1
28		# Storehouse client to save and restore flow data:
29		self.storehouse = StoreHouse(self.controller)
30
31		# Format of stored flow data:
32		# {'flow_persistence': {'dpid_str': {'flow_list': [
33		# {'command': '<add\|delete>',
34	1	# 'flow': {flow_dict}}]}}}
35		self.stored_flows = {}
36		self.resent_flows = set()
37
38	1	def execute(self):
39	1	"""Run once on NApp 'start' or in a loop.
40	1
41		The execute method is called by the run method of KytosNApp class.
42		Users shouldn't call this method directly.
43		"""
44		self._load_flows()
45	1
46	1	def shutdown(self):
47		"""Shutdown routine of the NApp."""
48	1	log.debug("flow-manager stopping")
49
50	1	@listen_to('kytos/topology.port.created')
51		def resend_stored_flows(self, event):
52	1	"""Resend stored Flows."""
53	1	dpid = str(event.content['switch'])
54	1	switch = self.controller.get_switch_by_dpid(dpid)
55		# This can be a problem because this code is running a thread
56	1	if dpid in self.resent_flows:
57		log.info(f'Flow already resended to Switch {dpid}')
58	1	return
59	1	if dpid in self.stored_flows:
60	1	flow_list = self.stored_flows[dpid]['flow_list']
61		for flow in flow_list:
62		command = flow['command']
63		flows_dict = {"flows": [flow['flow']]}
64		self._install_flows(command, flows_dict, [switch])
65	1	self.resent_flows.add(dpid)
66		log.info(f'Flows resent to Switch {dpid}')
67	1
68	1	# pylint: disable=attribute-defined-outside-init
69	1	def _load_flows(self):
70	1	"""Load stored flows."""
71	1	try:
72		data = self.storehouse.get_data()['flow_persistence']
73		if 'id' in data:
74		del data['id']
75		self.stored_flows = data
76	1
77		except KeyError as error:
78	1	log.debug(f'There are no flows to load: {error}')
79		else:
80	1	log.info('Flows loaded.')
81	1
82		@staticmethod
83	1	def _generate_match_fields(flow):
84		"""Generate flow match fields."""
85	1	match_fields = {}
86		for field in flow:
87	1	if 'priority' in field:
88	1	match_fields['priority'] = flow['priority']
89		if 'cookie' in field:
90	1	match_fields['cookie'] = flow['cookie']
91	1	if 'match' in field:
92	1	match_fields.update(flow['match'])
93	1	return match_fields
94	1
95	1	def _is_equal_flows(self, flow_1, flow_2):
96		"""Check if two flows are equal."""
97	1	flow_1_match_fields = self._generate_match_fields(flow_1)
98		flow_2_match_fields = self._generate_match_fields(flow_2)
99	1	if flow_1_match_fields == flow_2_match_fields:
100		return True
101		return False
102	1
103		def _store_changed_flows(self, command, flow, switch):
104	1	"""Store changed flows.
105
106		Args:
107		command: Flow command to be installed
108		flow: Flows to be stored
109		switch: Switch target
110		"""
111		stored_flows_box = self.stored_flows.copy()
112	1	# if the flow has a destination dpid it can be stored.
113	1	if not switch:
114	1	log.info('The Flow cannot be stored, the destination switch '
115	1	f'have not been specified: {switch}')
116	1	return
117	1
118		installed_flow = {}
119	1	flow_list = []
120	1	installed_flow['command'] = command
121		installed_flow['flow'] = flow
122
123	1	serializer = FlowFactory.get_class(switch)
124	1	installed_flow_obj = serializer.from_dict(flow, switch)
125
126	1	if switch.id not in stored_flows_box:
127		# Switch not stored, add to box.
128	1	flow_list.append(installed_flow)
129		stored_flows_box[switch.id] = {"flow_list": flow_list}
130	1	else:
131		stored_flows = stored_flows_box[switch.id].get('flow_list', [])
132	1	# Check if flow already stored
133		for stored_flow in stored_flows:
134	1	stored_flow_obj = serializer.from_dict(stored_flow['flow'],
135	1	switch)
136		if installed_flow_obj.id == stored_flow_obj.id:
137	1	if stored_flow['command'] == installed_flow['command']:
138		log.debug('Data already stored.')
139		return
140	1	# Flow with inconsistency in "command" fields : Remove the
141	1	# old instruction. This happens when there is a stored
142		# instruction to install the flow, but the new instruction
143	1	# is to remove it. In this case, the old instruction is
144		# removed and the new one is stored.
145	1	stored_flow['command'] = installed_flow.get('command')
146	1	stored_flows.remove(stored_flow)
147	1	break
148	1
149	1	stored_flows.append(installed_flow)
150	1	stored_flows_box[switch.id]['flow_list'] = stored_flows
151
152		stored_flows_box['id'] = 'flow_persistence'
153	1	self.storehouse.save_flow(stored_flows_box)
154		del stored_flows_box['id']
155	1	self.stored_flows = stored_flows_box.copy()
156	1
157	1	@rest('v2/flows')
158		@rest('v2/flows/<dpid>')
159	1	def list(self, dpid=None):
160		"""Retrieve all flows from a switch identified by dpid.
161
162		If no dpid is specified, return all flows from all switches.
163		"""
164		if dpid is None:
165		switches = self.controller.switches.values()
166	1	else:
167	1	switches = [self.controller.get_switch_by_dpid(dpid)]
168	1
169	1	switch_flows = {}
170	1
171		for switch in switches:
172		flows_dict = [flow.as_dict() for flow in switch.flows]
173		switch_flows[switch.dpid] = {'flows': flows_dict}
174	1
175		return jsonify(switch_flows)
176
177		@rest('v2/flows', methods=['POST'])
178		@rest('v2/flows/<dpid>', methods=['POST'])
179		def add(self, dpid=None):
180		"""Install new flows in the switch identified by dpid.
181
182		If no dpid is specified, install flows in all switches.
183		"""
184		return self._send_flow_mods_from_request(dpid, "add")
185
186		@rest('v2/delete', methods=['POST'])
187		@rest('v2/delete/<dpid>', methods=['POST'])
188		@rest('v2/flows', methods=['DELETE'])
189		@rest('v2/flows/<dpid>', methods=['DELETE'])
190		def delete(self, dpid=None):
191		"""Delete existing flows in the switch identified by dpid.
192
193		If no dpid is specified, delete flows from all switches.
194		"""
195		return self._send_flow_mods_from_request(dpid, "delete")
196
197		def _get_all_switches_enabled(self):
198		"""Get a list of all switches enabled."""
199		switches = self.controller.switches.values()
200		return [switch for switch in switches if switch.is_enabled()]
201
202		def _send_flow_mods_from_request(self, dpid, command, flows_dict=None):
203		"""Install FlowsMods from request."""
204		if flows_dict is None:
205		flows_dict = request.get_json()
206		if flows_dict is None:
207		return jsonify({"response": 'flows dict is none.'}), 404
208
209		if dpid:
210		switch = self.controller.get_switch_by_dpid(dpid)
211		if not switch:
212		return jsonify({"response": 'dpid not found.'}), 404
213		elif switch.is_enabled() is False:
214		return jsonify({"response": 'switch is disabled.'}), 404
215		else:
216		self._install_flows(command, flows_dict, [switch])
217		else:
218		self._install_flows(command, flows_dict,
219		self._get_all_switches_enabled())
220
221		return jsonify({"response": "FlowMod Messages Sent"})
222
223		def _install_flows(self, command, flows_dict, switches=[]):
224		"""Execute all procedures to install flows in the switches.
225
226		Args:
227		command: Flow command to be installed
228		flows_dict: Dictionary with flows to be installed in the switches.
229		switches: A list of switches
230		"""
231		for switch in switches:
232		serializer = FlowFactory.get_class(switch)
233		flows = flows_dict.get('flows', [])
234		for flow_dict in flows:
235		flow = serializer.from_dict(flow_dict, switch)
236		if command == "delete":
237		flow_mod = flow.as_of_delete_flow_mod()
238		elif command == "add":
239		flow_mod = flow.as_of_add_flow_mod()
240		else:
241		raise InvalidCommandError
242		self._send_flow_mod(flow.switch, flow_mod)
243		self._add_flow_mod_sent(flow_mod.header.xid, flow, command)
244
245		self._send_napp_event(switch, flow, command)
246		self._store_changed_flows(command, flow_dict, switch)
247
248		def _add_flow_mod_sent(self, xid, flow, command):
249		"""Add the flow mod to the list of flow mods sent."""
250		if len(self._flow_mods_sent) >= self._flow_mods_sent_max_size:
251		self._flow_mods_sent.popitem(last=False)
252		self._flow_mods_sent[xid] = (flow, command)
253
254		def _send_flow_mod(self, switch, flow_mod):
255		event_name = 'kytos/flow_manager.messages.out.ofpt_flow_mod'
256
257		content = {'destination': switch.connection,
258		'message': flow_mod}
259
260		event = KytosEvent(name=event_name, content=content)
261		self.controller.buffers.msg_out.put(event)
262
263		def _send_napp_event(self, switch, flow, command, **kwargs):
264		"""Send an Event to other apps informing about a FlowMod."""
265		if command == 'add':
266		name = 'kytos/flow_manager.flow.added'
267		elif command == 'delete':
268		name = 'kytos/flow_manager.flow.removed'
269		elif command == 'error':
270		name = 'kytos/flow_manager.flow.error'
271		else:
272		raise InvalidCommandError
273		content = {'datapath': switch,
274		'flow': flow}
275		content.update(kwargs)
276		event_app = KytosEvent(name, content)
277		self.controller.buffers.app.put(event_app)
278
279		@listen_to('..of_core..ofpt_error')
280		def handle_errors(self, event):
281		"""Receive OpenFlow error and send a event.
282
283		The event is sent only if the error is related to a request made
284		by flow_manager.
285		"""
286		xid = event.content["message"].header.xid.value
287		error_type = event.content["message"].error_type
288		error_code = event.content["message"].code
289		try:
290		flow, error_command = self._flow_mods_sent[xid]
291		except KeyError:
292		pass
293		else:
294		self._send_napp_event(flow.switch, flow, 'error',
295		error_command=error_command,
296		error_type=error_type, error_code=error_code)
297

kytos / flow_manager

Pull Request — master (#90)

build.main.Main._add_flow_mod_sent() A

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like