build.main.Main.shutdown() - 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 2020-12-16 19:59 UTC

build.main.Main.shutdown() A

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	3
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes

Metric	Value
eloc	2
dl	0
loc	3
ccs	2
cts	2
cp	1
rs	10
c	0
b	0
f	0
cc	1
nop	1
crap	1

"""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 CONSISTENCY_INTERVAL, 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()
        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)

            flow = {'flows': [stored_flow['flow']]}

            if not self._is_flow_in_list(stored_flow_obj, switch.flows):
                log.info('A problem with consistency were dectected.')
                if command == 'add':
                    self._install_flows(command, flow, [switch])
                    log.info(f'Flow forwarded to switch {dpid} to be '
                             'installed.')
            elif command == 'delete':
                self._install_flows(command, flow, [switch])
                log.info(f'Flow forwarded to switch {dpid} to be deleted.')

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

        serializer = FlowFactory.get_class(switch)
        stored_flow = self.stored_flows[dpid]['flow_list']
        stored_flows_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):
                log.info('A problem with consistency were dectected.')
                flow = {'flows': [installed_flow.as_dict()]}
                command = 'delete'
                self._install_flows(command, flow, [switch])
                log.info(f'Flow forwarded to switch {dpid} to be deleted.')

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

kytos / flow_manager

Pull Request — master (#96)

build.main.Main.shutdown() A

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