build.main.Main._generate_match_fields() - 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 Humberto

created 2020-11-12 17:52 UTC

build.main.Main._generate_match_fields() B

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	14
Code Lines	13

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	10
CRAP Score	6

Importance

Changes

Metric	Value
cc	6
eloc	13
nop	1
dl	0
loc	14
ccs	10
cts	10
cp	1
crap	6
rs	8.6666
c	0
b	0
f	0

"""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(flows):
        """Generate flow match fields."""
        match_fields = {}
        flow = flows['flow']
        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:
                for m_field, value in flow['match'].items():
                    match_fields[m_field] = value
        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

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

        if switch.id not in stored_flows_box:
            # Switch not stored, add to box.
            flow_list.append(new_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:
                if self._is_equal_flows(new_flow, stored_flow):
                    if stored_flow['command'] == new_flow['command']:
                        log.debug('Data already stored.')
                        return
                    # Command conflict. Remove the old instruction.
                    # There is a stored instruction to install the flow,
                    # but the new instruction is to remove it.
                    # In this case, remove the old instruction
                    # and store the new.
                    stored_flow['command'] = new_flow.get('command')
                    stored_flows.remove(stored_flow)
                    break

            stored_flows.append(new_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(flows):
84		"""Generate flow match fields."""
85	1	match_fields = {}
86		flow = flows['flow']
87	1	for field in flow:
88	1	if 'priority' in field:
89		match_fields['priority'] = flow['priority']
90	1	if 'cookie' in field:
91	1	match_fields['cookie'] = flow['cookie']
92	1	if 'match' in field:
93	1	for m_field, value in flow['match'].items():
94	1	match_fields[m_field] = value
95	1	return match_fields
96
97	1	def _is_equal_flows(self, flow_1, flow_2):
98		"""Check if two flows are equal."""
99	1	flow_1_match_fields = self._generate_match_fields(flow_1)
100		flow_2_match_fields = self._generate_match_fields(flow_2)
101		if flow_1_match_fields == flow_2_match_fields:
102	1	return True
103		return False
104	1
105		def _store_changed_flows(self, command, flow, switch):
106		"""Store changed flows.
107
108		Args:
109		command: Flow command to be installed
110		flow: Flows to be stored
111		switch: Switch target
112	1	"""
113	1	stored_flows_box = self.stored_flows.copy()
114	1	# if the flow has a destination dpid it can be stored.
115	1	if not switch:
116	1	log.info('The Flow cannot be stored, the destination switch '
117	1	f'have not been specified: {switch}')
118		return
119	1
120	1	new_flow = {}
121		flow_list = []
122		new_flow['command'] = command
123	1	new_flow['flow'] = flow
124	1
125		if switch.id not in stored_flows_box:
126	1	# Switch not stored, add to box.
127		flow_list.append(new_flow)
128	1	stored_flows_box[switch.id] = {"flow_list": flow_list}
129		else:
130	1	stored_flows = stored_flows_box[switch.id].get('flow_list', [])
131		# Check if flow already stored
132	1	for stored_flow in stored_flows:
133		if self._is_equal_flows(new_flow, stored_flow):
134	1	if stored_flow['command'] == new_flow['command']:
135	1	log.debug('Data already stored.')
136		return
137	1	# Command conflict. Remove the old instruction.
138		# There is a stored instruction to install the flow,
139		# but the new instruction is to remove it.
140	1	# In this case, remove the old instruction
141	1	# and store the new.
142		stored_flow['command'] = new_flow.get('command')
143	1	stored_flows.remove(stored_flow)
144		break
145	1
146	1	stored_flows.append(new_flow)
147	1	stored_flows_box[switch.id]['flow_list'] = stored_flows
148	1
149	1	stored_flows_box['id'] = 'flow_persistence'
150	1	self.storehouse.save_flow(stored_flows_box)
151		del stored_flows_box['id']
152		self.stored_flows = stored_flows_box.copy()
153	1
154		@rest('v2/flows')
155	1	@rest('v2/flows/<dpid>')
156	1	def list(self, dpid=None):
157	1	"""Retrieve all flows from a switch identified by dpid.
158
159	1	If no dpid is specified, return all flows from all switches.
160		"""
161		if dpid is None:
162		switches = self.controller.switches.values()
163		else:
164		switches = [self.controller.get_switch_by_dpid(dpid)]
165
166	1	switch_flows = {}
167	1
168	1	for switch in switches:
169	1	flows_dict = [flow.as_dict() for flow in switch.flows]
170	1	switch_flows[switch.dpid] = {'flows': flows_dict}
171
172		return jsonify(switch_flows)
173
174	1	@rest('v2/flows', methods=['POST'])
175		@rest('v2/flows/<dpid>', methods=['POST'])
176		def add(self, dpid=None):
177		"""Install new flows in the switch identified by dpid.
178
179		If no dpid is specified, install flows in all switches.
180		"""
181		return self._send_flow_mods_from_request(dpid, "add")
182
183		@rest('v2/delete', methods=['POST'])
184		@rest('v2/delete/<dpid>', methods=['POST'])
185		@rest('v2/flows', methods=['DELETE'])
186		@rest('v2/flows/<dpid>', methods=['DELETE'])
187		def delete(self, dpid=None):
188		"""Delete existing flows in the switch identified by dpid.
189
190		If no dpid is specified, delete flows from all switches.
191		"""
192		return self._send_flow_mods_from_request(dpid, "delete")
193
194		def _get_all_switches_enabled(self):
195		"""Get a list of all switches enabled."""
196		switches = self.controller.switches.values()
197		return [switch for switch in switches if switch.is_enabled()]
198
199		def _send_flow_mods_from_request(self, dpid, command, flows_dict=None):
200		"""Install FlowsMods from request."""
201		if flows_dict is None:
202		flows_dict = request.get_json()
203		if flows_dict is None:
204		return jsonify({"response": 'flows dict is none.'}), 404
205
206		if dpid:
207		switch = self.controller.get_switch_by_dpid(dpid)
208		if not switch:
209		return jsonify({"response": 'dpid not found.'}), 404
210		elif switch.is_enabled() is False:
211		return jsonify({"response": 'switch is disabled.'}), 404
212		else:
213		self._install_flows(command, flows_dict, [switch])
214		else:
215		self._install_flows(command, flows_dict,
216		self._get_all_switches_enabled())
217
218		return jsonify({"response": "FlowMod Messages Sent"})
219
220		def _install_flows(self, command, flows_dict, switches=[]):
221		"""Execute all procedures to install flows in the switches.
222
223		Args:
224		command: Flow command to be installed
225		flows_dict: Dictionary with flows to be installed in the switches.
226		switches: A list of switches
227		"""
228		for switch in switches:
229		serializer = FlowFactory.get_class(switch)
230		flows = flows_dict.get('flows', [])
231		for flow_dict in flows:
232		flow = serializer.from_dict(flow_dict, switch)
233		if command == "delete":
234		flow_mod = flow.as_of_delete_flow_mod()
235		elif command == "add":
236		flow_mod = flow.as_of_add_flow_mod()
237		else:
238		raise InvalidCommandError
239		self._send_flow_mod(flow.switch, flow_mod)
240		self._add_flow_mod_sent(flow_mod.header.xid, flow, command)
241
242		self._send_napp_event(switch, flow, command)
243		self._store_changed_flows(command, flow_dict, switch)
244
245		def _add_flow_mod_sent(self, xid, flow, command):
246		"""Add the flow mod to the list of flow mods sent."""
247		if len(self._flow_mods_sent) >= self._flow_mods_sent_max_size:
248		self._flow_mods_sent.popitem(last=False)
249		self._flow_mods_sent[xid] = (flow, command)
250
251		def _send_flow_mod(self, switch, flow_mod):
252		event_name = 'kytos/flow_manager.messages.out.ofpt_flow_mod'
253
254		content = {'destination': switch.connection,
255		'message': flow_mod}
256
257		event = KytosEvent(name=event_name, content=content)
258		self.controller.buffers.msg_out.put(event)
259
260		def _send_napp_event(self, switch, flow, command, **kwargs):
261		"""Send an Event to other apps informing about a FlowMod."""
262		if command == 'add':
263		name = 'kytos/flow_manager.flow.added'
264		elif command == 'delete':
265		name = 'kytos/flow_manager.flow.removed'
266		elif command == 'error':
267		name = 'kytos/flow_manager.flow.error'
268		else:
269		raise InvalidCommandError
270		content = {'datapath': switch,
271		'flow': flow}
272		content.update(kwargs)
273		event_app = KytosEvent(name, content)
274		self.controller.buffers.app.put(event_app)
275
276		@listen_to('..of_core..ofpt_error')
277		def handle_errors(self, event):
278		"""Receive OpenFlow error and send a event.
279
280		The event is sent only if the error is related to a request made
281		by flow_manager.
282		"""
283		xid = event.content["message"].header.xid.value
284		error_type = event.content["message"].error_type
285		error_code = event.content["message"].code
286		try:
287		flow, error_command = self._flow_mods_sent[xid]
288		except KeyError:
289		pass
290		else:
291		self._send_napp_event(flow.switch, flow, 'error',
292		error_command=error_command,
293		error_type=error_type, error_code=error_code)
294

kytos / flow_manager

Pull Request — master (#90)

build.main.Main._generate_match_fields() B

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like