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

Test Failed

Pull Request — master (#96)

by Jose

created 2020-12-15 15:55 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, CONSISTENCY_INTERVAL


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()
        if CONSISTENCY_INTERVAL > 0:
            self.execute_as_loop(CONSISTENCY_INTERVAL)

    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()

        if CONSISTENCY_INTERVAL > 0:
            self.consistency_check()

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

    def consistency_check(self):
        """Check the consistency of flows in each switch."""
        switches = self.controller.switches.values()

        for switch in switches:
            if switch.dpid in self.stored_flows:
                self.consistency_of_flows_in_switch(switch)
                self.consistency_of_flows_in_storehouse(switch)
            else:
                continue

    def consistency_of_flows_in_switch(self, switch):
        """Check consistency of installed flows for a specific switch."""
        dpid = switch.dpid

        # Flows stored in storehouse
        stored_flows = self.stored_flows[dpid]['flow_list']

        serializer = FlowFactory.get_class(switch)

        for stored_flow in stored_flows:
            command = stored_flow['command']

            stored_flow_obj = serializer.from_dict(stored_flow['flow'], switch)

            if not self._is_flow_in_list(stored_flow_obj, switch):
                if command == 'add':
                    msg = f'Flow forwarded to switch {dpid} to be installed.'
                    self._resolve_inconsistency(command, stored_flow,
                                                [switch], msg)
            elif command == 'delete':
                msg = f'Flow forwarded to switch {dpid} to be deleted.'
                self._resolve_inconsistency(command, stored_flow,
                                            [switch], msg)

    def consistency_of_flows_in_storehouse(self, switch):
        """Check consistency of installed flows for a specific switch."""

        serializer = FlowFactory.get_class(switch)
        stored_flow = self.stored_flows[dpid]['flow_list']

        stored_flow_list = [serializer.from_dict(stored_flow['flow'], switch)
                            for stored_flow in stored_flow]

        for installed_flow in switch.flows:
            if not self._is_flow_in_list(installed_flow, stored_flows_list):

                flow = {'flows': [installed_flow]}
                command = 'delete'
                msg = f'Flow forwarded to switch {dpid} to be deleted.'
                self._resolve_inconsistency(command, flow, [switch], msg)

    def _resolve_inconsistency(self, command, flow, switch, msg):
        """Forward flow to be installed resolving the inconsistency."""
        # criar flow_dict
        flow_to_install = {'flows': [flow]}
        log.info('A problem with consistency were dectected.')
        self._install_flows(command, flow_to_install, switch)
        log.info(msg)

    def _is_flow_in_list(self, flow, flow_list):
        """Check if the flow is in flow_list."""
        for flow_from_list in flow_list:
            if flow == flow_from_list:
                return True
        return False

    # 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.')

    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 == stored_flow_obj:
                    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, CONSISTENCY_INTERVAL
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		if CONSISTENCY_INTERVAL > 0:
38	1	self.execute_as_loop(CONSISTENCY_INTERVAL)
39	1
40	1	def execute(self):
41		"""Run once on NApp 'start' or in a loop.
42
43		The execute method is called by the run method of KytosNApp class.
44		Users shouldn't call this method directly.
45	1	"""
46	1	self._load_flows()
47
48	1	if CONSISTENCY_INTERVAL > 0:
49		self.consistency_check()
50	1
51		def shutdown(self):
52	1	"""Shutdown routine of the NApp."""
53	1	log.debug("flow-manager stopping")
54	1
55		def consistency_check(self):
56	1	"""Check the consistency of flows in each switch."""
57		switches = self.controller.switches.values()
58	1
59	1	for switch in switches:
60	1	if switch.dpid in self.stored_flows:
61		self.consistency_of_flows_in_switch(switch)
62		self.consistency_of_flows_in_storehouse(switch)
63		else:
64		continue
65	1
66		def consistency_of_flows_in_switch(self, switch):
67	1	"""Check consistency of installed flows for a specific switch."""
68	1	dpid = switch.dpid
69	1
70	1	# Flows stored in storehouse
71	1	stored_flows = self.stored_flows[dpid]['flow_list']
72
73		serializer = FlowFactory.get_class(switch)
74
75		for stored_flow in stored_flows:
76	1	command = stored_flow['command']
77
78	1	stored_flow_obj = serializer.from_dict(stored_flow['flow'], switch)
79
80	1	if not self._is_flow_in_list(stored_flow_obj, switch):
81	1	if command == 'add':
82		msg = f'Flow forwarded to switch {dpid} to be installed.'
83	1	self._resolve_inconsistency(command, stored_flow,
84		[switch], msg)
85	1	elif command == 'delete':
86		msg = f'Flow forwarded to switch {dpid} to be deleted.'
87	1	self._resolve_inconsistency(command, stored_flow,
88	1	[switch], msg)
89
90	1	def consistency_of_flows_in_storehouse(self, switch):
91	1	"""Check consistency of installed flows for a specific switch."""
92	1
93	1	serializer = FlowFactory.get_class(switch)
94	1	stored_flow = self.stored_flows[dpid]['flow_list']
		0 ignored issues – show Comprehensibility Best Practice introduced 2020-12-15 15:57 UTC by Report Bug Copy Issue Report The variable `dpid` does not seem to be defined. Loading history...
95	1	stored_flow_list = [serializer.from_dict(stored_flow['flow'], switch)
96		for stored_flow in stored_flow]
97	1
98		for installed_flow in switch.flows:
99	1	if not self._is_flow_in_list(installed_flow, stored_flows_list):
		0 ignored issues – show Comprehensibility Best Practice introduced 2020-12-15 15:57 UTC by Report Bug Copy Issue Report The variable `stored_flows_list` does not seem to be defined. Loading history...
100		flow = {'flows': [installed_flow]}
101		command = 'delete'
102	1	msg = f'Flow forwarded to switch {dpid} to be deleted.'
103		self._resolve_inconsistency(command, flow, [switch], msg)
104	1
105		def _resolve_inconsistency(self, command, flow, switch, msg):
106		"""Forward flow to be installed resolving the inconsistency."""
107		# criar flow_dict
108		flow_to_install = {'flows': [flow]}
109		log.info('A problem with consistency were dectected.')
110		self._install_flows(command, flow_to_install, switch)
111		log.info(msg)
112	1
113	1	def _is_flow_in_list(self, flow, flow_list):
114	1	"""Check if the flow is in flow_list."""
115	1	for flow_from_list in flow_list:
116	1	if flow == flow_from_list:
117	1	return True
118		return False
119	1
120	1	# pylint: disable=attribute-defined-outside-init
121		def _load_flows(self):
122		"""Load stored flows."""
123	1	try:
124	1	data = self.storehouse.get_data()['flow_persistence']
125		if 'id' in data:
126	1	del data['id']
127		self.stored_flows = data
128	1
129		except KeyError as error:
130	1	log.debug(f'There are no flows to load: {error}')
131		else:
132	1	log.info('Flows loaded.')
133
134	1	def _store_changed_flows(self, command, flow, switch):
135	1	"""Store changed flows.
136
137	1	Args:
138		command: Flow command to be installed
139		flow: Flows to be stored
140	1	switch: Switch target
141	1	"""
142		stored_flows_box = self.stored_flows.copy()
143	1	# if the flow has a destination dpid it can be stored.
144		if not switch:
145	1	log.info('The Flow cannot be stored, the destination switch '
146	1	f'have not been specified: {switch}')
147	1	return
148	1	installed_flow = {}
149	1	flow_list = []
150	1	installed_flow['command'] = command
151		installed_flow['flow'] = flow
152
153	1	serializer = FlowFactory.get_class(switch)
154		installed_flow_obj = serializer.from_dict(flow, switch)
155	1
156	1	if switch.id not in stored_flows_box:
157	1	# Switch not stored, add to box.
158		flow_list.append(installed_flow)
159	1	stored_flows_box[switch.id] = {'flow_list': flow_list}
160		else:
161		stored_flows = stored_flows_box[switch.id].get('flow_list', [])
162		# Check if flow already stored
163		for stored_flow in stored_flows:
164		stored_flow_obj = serializer.from_dict(stored_flow['flow'],
165		switch)
166	1	if installed_flow_obj == stored_flow_obj:
167	1	if stored_flow['command'] == installed_flow['command']:
168	1	log.debug('Data already stored.')
169	1	return
170	1	# Flow with inconsistency in "command" fields : Remove the
171		# old instruction. This happens when there is a stored
172		# instruction to install the flow, but the new instruction
173		# is to remove it. In this case, the old instruction is
174	1	# removed and the new one is stored.
175		stored_flow['command'] = installed_flow.get('command')
176		stored_flows.remove(stored_flow)
177		break
178
179		stored_flows.append(installed_flow)
180		stored_flows_box[switch.id]['flow_list'] = stored_flows
181
182		stored_flows_box['id'] = 'flow_persistence'
183		self.storehouse.save_flow(stored_flows_box)
184		del stored_flows_box['id']
185		self.stored_flows = stored_flows_box.copy()
186
187		@rest('v2/flows')
188		@rest('v2/flows/<dpid>')
189		def list(self, dpid=None):
190		"""Retrieve all flows from a switch identified by dpid.
191
192		If no dpid is specified, return all flows from all switches.
193		"""
194		if dpid is None:
195		switches = self.controller.switches.values()
196		else:
197		switches = [self.controller.get_switch_by_dpid(dpid)]
198
199		switch_flows = {}
200
201		for switch in switches:
202		flows_dict = [flow.as_dict() for flow in switch.flows]
203		switch_flows[switch.dpid] = {'flows': flows_dict}
204
205		return jsonify(switch_flows)
206
207		@rest('v2/flows', methods=['POST'])
208		@rest('v2/flows/<dpid>', methods=['POST'])
209		def add(self, dpid=None):
210		"""Install new flows in the switch identified by dpid.
211
212		If no dpid is specified, install flows in all switches.
213		"""
214		return self._send_flow_mods_from_request(dpid, "add")
215
216		@rest('v2/delete', methods=['POST'])
217		@rest('v2/delete/<dpid>', methods=['POST'])
218		@rest('v2/flows', methods=['DELETE'])
219		@rest('v2/flows/<dpid>', methods=['DELETE'])
220		def delete(self, dpid=None):
221		"""Delete existing flows in the switch identified by dpid.
222
223		If no dpid is specified, delete flows from all switches.
224		"""
225		return self._send_flow_mods_from_request(dpid, "delete")
226
227		def _get_all_switches_enabled(self):
228		"""Get a list of all switches enabled."""
229		switches = self.controller.switches.values()
230		return [switch for switch in switches if switch.is_enabled()]
231
232		def _send_flow_mods_from_request(self, dpid, command, flows_dict=None):
233		"""Install FlowsMods from request."""
234		if flows_dict is None:
235		flows_dict = request.get_json()
236		if flows_dict is None:
237		return jsonify({"response": 'flows dict is none.'}), 404
238
239		if dpid:
240		switch = self.controller.get_switch_by_dpid(dpid)
241		if not switch:
242		return jsonify({"response": 'dpid not found.'}), 404
243		elif switch.is_enabled() is False:
244		return jsonify({"response": 'switch is disabled.'}), 404
245		else:
246		self._install_flows(command, flows_dict, [switch])
247		else:
248		self._install_flows(command, flows_dict,
249		self._get_all_switches_enabled())
250
251		return jsonify({"response": "FlowMod Messages Sent"})
252
253		def _install_flows(self, command, flows_dict, switches=[]):
254		"""Execute all procedures to install flows in the switches.
255
256		Args:
257		command: Flow command to be installed
258		flows_dict: Dictionary with flows to be installed in the switches.
259		switches: A list of switches
260		"""
261		for switch in switches:
262		serializer = FlowFactory.get_class(switch)
263		flows = flows_dict.get('flows', [])
264		for flow_dict in flows:
265		flow = serializer.from_dict(flow_dict, switch)
266		if command == "delete":
267		flow_mod = flow.as_of_delete_flow_mod()
268		elif command == "add":
269		flow_mod = flow.as_of_add_flow_mod()
270		else:
271		raise InvalidCommandError
272		self._send_flow_mod(flow.switch, flow_mod)
273		self._add_flow_mod_sent(flow_mod.header.xid, flow, command)
274
275		self._send_napp_event(switch, flow, command)
276		self._store_changed_flows(command, flow_dict, switch)
277
278		def _add_flow_mod_sent(self, xid, flow, command):
279		"""Add the flow mod to the list of flow mods sent."""
280		if len(self._flow_mods_sent) >= self._flow_mods_sent_max_size:
281		self._flow_mods_sent.popitem(last=False)
282		self._flow_mods_sent[xid] = (flow, command)
283
284		def _send_flow_mod(self, switch, flow_mod):
285		event_name = 'kytos/flow_manager.messages.out.ofpt_flow_mod'
286
287		content = {'destination': switch.connection,
288		'message': flow_mod}
289
290		event = KytosEvent(name=event_name, content=content)
291		self.controller.buffers.msg_out.put(event)
292
293		def _send_napp_event(self, switch, flow, command, **kwargs):
294		"""Send an Event to other apps informing about a FlowMod."""
295		if command == 'add':
296		name = 'kytos/flow_manager.flow.added'
297		elif command == 'delete':
298		name = 'kytos/flow_manager.flow.removed'
299		elif command == 'error':
300		name = 'kytos/flow_manager.flow.error'
301		else:
302		raise InvalidCommandError
303		content = {'datapath': switch,
304		'flow': flow}
305		content.update(kwargs)
306		event_app = KytosEvent(name, content)
307		self.controller.buffers.app.put(event_app)
308
309		@listen_to('..of_core..ofpt_error')
310		def handle_errors(self, event):
311		"""Receive OpenFlow error and send a event.
312
313		The event is sent only if the error is related to a request made
314		by flow_manager.
315		"""
316		xid = event.content["message"].header.xid.value
317		error_type = event.content["message"].error_type
318		error_code = event.content["message"].code
319		try:
320		flow, error_command = self._flow_mods_sent[xid]
321		except KeyError:
322		pass
323		else:
324		self._send_napp_event(flow.switch, flow, 'error',
325		error_command=error_command,
326		error_type=error_type, error_code=error_code)
327

kytos / flow_manager

Pull Request — master (#96)

build.main.Main._add_flow_mod_sent() A

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