Refactors autoscaling module to separate concerns and allow better control of db connections

Change-Id: I57034d34ae2fbb3c4aeda784f9542e643d348460
Signed-off-by: Benjamin Diaz <bdiaz@whitestack.com>
diff --git a/osm_policy_module/autoscaling/service.py b/osm_policy_module/autoscaling/service.py
new file mode 100644
index 0000000..e1f0704
--- /dev/null
+++ b/osm_policy_module/autoscaling/service.py
@@ -0,0 +1,311 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2018 Whitestack, LLC
+# *************************************************************
+
+# This file is part of OSM Monitoring module
+# All Rights Reserved to Whitestack, LLC
+
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+
+#         http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: bdiaz@whitestack.com or glavado@whitestack.com
+##
+import asyncio
+import datetime
+import json
+import logging
+
+from osm_policy_module.common.common_db_client import CommonDbClient
+from osm_policy_module.common.lcm_client import LcmClient
+from osm_policy_module.common.mon_client import MonClient
+from osm_policy_module.core import database
+from osm_policy_module.core.config import Config
+from osm_policy_module.core.database import ScalingGroup, ScalingAlarm, ScalingPolicy, ScalingCriteria
+from osm_policy_module.core.exceptions import VdurNotFound
+from osm_policy_module.utils.vnfd import VnfdUtils
+
+log = logging.getLogger(__name__)
+
+
+class Service:
+
+    def __init__(self, config: Config, loop=None):
+        self.conf = config
+        if not loop:
+            loop = asyncio.get_event_loop()
+        self.loop = loop
+        self.db_client = CommonDbClient(config)
+        self.mon_client = MonClient(config, loop=self.loop)
+        self.lcm_client = LcmClient(config, loop=self.loop)
+
+    async def configure_scaling_groups(self, nsr_id: str):
+        log.debug("_configure_scaling_groups: %s", nsr_id)
+        alarms_created = []
+        database.db.connect()
+        with database.db.atomic() as tx:
+            try:
+                vnfrs = self.db_client.get_vnfrs(nsr_id)
+                for vnfr in vnfrs:
+                    log.info("Processing vnfr: %s", vnfr)
+                    vnfd = self.db_client.get_vnfd(vnfr['vnfd-id'])
+                    log.info("Looking for vnfd %s", vnfr['vnfd-id'])
+                    if 'scaling-group-descriptor' not in vnfd:
+                        continue
+                    scaling_groups = vnfd['scaling-group-descriptor']
+                    vnf_monitoring_params = vnfd['monitoring-param']
+                    for scaling_group in scaling_groups:
+                        try:
+                            scaling_group_record = ScalingGroup.select().where(
+                                ScalingGroup.nsr_id == nsr_id,
+                                ScalingGroup.vnf_member_index == int(vnfr['member-vnf-index-ref']),
+                                ScalingGroup.name == scaling_group['name']
+                            ).get()
+                            log.info("Found existing scaling group record in DB...")
+                        except ScalingGroup.DoesNotExist:
+                            log.info("Creating scaling group record in DB...")
+                            scaling_group_record = ScalingGroup.create(
+                                nsr_id=nsr_id,
+                                vnf_member_index=vnfr['member-vnf-index-ref'],
+                                name=scaling_group['name'],
+                                content=json.dumps(scaling_group)
+                            )
+                            log.info(
+                                "Created scaling group record in DB : nsr_id=%s, vnf_member_index=%s, name=%s",
+                                scaling_group_record.nsr_id,
+                                scaling_group_record.vnf_member_index,
+                                scaling_group_record.name)
+                        for scaling_policy in scaling_group['scaling-policy']:
+                            if scaling_policy['scaling-type'] != 'automatic':
+                                continue
+                            try:
+                                scaling_policy_record = ScalingPolicy.select().join(ScalingGroup).where(
+                                    ScalingPolicy.name == scaling_policy['name'],
+                                    ScalingGroup.id == scaling_group_record.id
+                                ).get()
+                                log.info("Found existing scaling policy record in DB...")
+                            except ScalingPolicy.DoesNotExist:
+                                log.info("Creating scaling policy record in DB...")
+                                scaling_policy_record = ScalingPolicy.create(
+                                    nsr_id=nsr_id,
+                                    name=scaling_policy['name'],
+                                    cooldown_time=scaling_policy['cooldown-time'],
+                                    scaling_group=scaling_group_record
+                                )
+                                log.info("Created scaling policy record in DB : name=%s, scaling_group.name=%s",
+                                         scaling_policy_record.name,
+                                         scaling_policy_record.scaling_group.name)
+
+                            for scaling_criteria in scaling_policy['scaling-criteria']:
+                                try:
+                                    scaling_criteria_record = ScalingCriteria.select().join(ScalingPolicy).where(
+                                        ScalingPolicy.id == scaling_policy_record.id,
+                                        ScalingCriteria.name == scaling_criteria['name']
+                                    ).get()
+                                    log.info("Found existing scaling criteria record in DB...")
+                                except ScalingCriteria.DoesNotExist:
+                                    log.info("Creating scaling criteria record in DB...")
+                                    scaling_criteria_record = ScalingCriteria.create(
+                                        nsr_id=nsr_id,
+                                        name=scaling_criteria['name'],
+                                        scaling_policy=scaling_policy_record
+                                    )
+                                    log.info(
+                                        "Created scaling criteria record in DB : name=%s, scaling_policy.name=%s",
+                                        scaling_criteria_record.name,
+                                        scaling_criteria_record.scaling_policy.name)
+
+                                vnf_monitoring_param = next(
+                                    filter(
+                                        lambda param: param['id'] == scaling_criteria[
+                                            'vnf-monitoring-param-ref'
+                                        ],
+                                        vnf_monitoring_params)
+                                )
+                                if 'vdu-monitoring-param' in vnf_monitoring_param:
+                                    vdurs = list(
+                                        filter(
+                                            lambda vdur: vdur['vdu-id-ref'] == vnf_monitoring_param
+                                            ['vdu-monitoring-param']
+                                            ['vdu-ref'],
+                                            vnfr['vdur']
+                                        )
+                                    )
+                                elif 'vdu-metric' in vnf_monitoring_param:
+                                    vdurs = list(
+                                        filter(
+                                            lambda vdur: vdur['vdu-id-ref'] == vnf_monitoring_param
+                                            ['vdu-metric']
+                                            ['vdu-ref'],
+                                            vnfr['vdur']
+                                        )
+                                    )
+                                elif 'vnf-metric' in vnf_monitoring_param:
+                                    vdu = VnfdUtils.get_mgmt_vdu(vnfd)
+                                    vdurs = list(
+                                        filter(
+                                            lambda vdur: vdur['vdu-id-ref'] == vdu['id'],
+                                            vnfr['vdur']
+                                        )
+                                    )
+                                else:
+                                    log.warning(
+                                        "Scaling criteria is referring to a vnf-monitoring-param that does not "
+                                        "contain a reference to a vdu or vnf metric.")
+                                    continue
+                                for vdur in vdurs:
+                                    log.info("Creating alarm for vdur %s ", vdur)
+                                    try:
+                                        (ScalingAlarm.select()
+                                         .join(ScalingCriteria)
+                                         .join(ScalingPolicy)
+                                         .join(ScalingGroup)
+                                         .where(
+                                            ScalingAlarm.vdu_name == vdur['name'],
+                                            ScalingCriteria.name == scaling_criteria['name'],
+                                            ScalingPolicy.name == scaling_policy['name'],
+                                            ScalingGroup.nsr_id == nsr_id
+                                        ).get())
+                                        log.debug("vdu %s already has an alarm configured", vdur['name'])
+                                        continue
+                                    except ScalingAlarm.DoesNotExist:
+                                        pass
+                                    alarm_uuid = await self.mon_client.create_alarm(
+                                        metric_name=vnf_monitoring_param['id'],
+                                        ns_id=nsr_id,
+                                        vdu_name=vdur['name'],
+                                        vnf_member_index=vnfr['member-vnf-index-ref'],
+                                        threshold=scaling_criteria['scale-in-threshold'],
+                                        operation=scaling_criteria['scale-in-relational-operation'],
+                                        statistic=vnf_monitoring_param['aggregation-type']
+                                    )
+                                    alarm = ScalingAlarm.create(
+                                        alarm_uuid=alarm_uuid,
+                                        action='scale_in',
+                                        vnf_member_index=int(vnfr['member-vnf-index-ref']),
+                                        vdu_name=vdur['name'],
+                                        scaling_criteria=scaling_criteria_record
+                                    )
+                                    alarms_created.append(alarm)
+                                    alarm_uuid = await self.mon_client.create_alarm(
+                                        metric_name=vnf_monitoring_param['id'],
+                                        ns_id=nsr_id,
+                                        vdu_name=vdur['name'],
+                                        vnf_member_index=vnfr['member-vnf-index-ref'],
+                                        threshold=scaling_criteria['scale-out-threshold'],
+                                        operation=scaling_criteria['scale-out-relational-operation'],
+                                        statistic=vnf_monitoring_param['aggregation-type']
+                                    )
+                                    alarm = ScalingAlarm.create(
+                                        alarm_uuid=alarm_uuid,
+                                        action='scale_out',
+                                        vnf_member_index=int(vnfr['member-vnf-index-ref']),
+                                        vdu_name=vdur['name'],
+                                        scaling_criteria=scaling_criteria_record
+                                    )
+                                    alarms_created.append(alarm)
+
+            except Exception as e:
+                log.exception("Error configuring scaling groups:")
+                tx.rollback()
+                if len(alarms_created) > 0:
+                    log.info("Cleaning alarm resources in MON")
+                    for alarm in alarms_created:
+                        await self.mon_client.delete_alarm(alarm.scaling_criteria.scaling_policy.scaling_group.nsr_id,
+                                                           alarm.vnf_member_index,
+                                                           alarm.vdu_name,
+                                                           alarm.alarm_uuid)
+                raise e
+        database.db.close()
+
+    async def delete_scaling_groups(self, nsr_id: str):
+        database.db.connect()
+        with database.db.atomic() as tx:
+            try:
+                for scaling_group in ScalingGroup.select().where(ScalingGroup.nsr_id == nsr_id):
+                    for scaling_policy in scaling_group.scaling_policies:
+                        for scaling_criteria in scaling_policy.scaling_criterias:
+                            for alarm in scaling_criteria.scaling_alarms:
+                                try:
+                                    await self.mon_client.delete_alarm(
+                                        alarm.scaling_criteria.scaling_policy.scaling_group.nsr_id,
+                                        alarm.vnf_member_index,
+                                        alarm.vdu_name,
+                                        alarm.alarm_uuid)
+                                except ValueError:
+                                    log.exception("Error deleting alarm in MON %s", alarm.alarm_uuid)
+                                alarm.delete_instance()
+                            scaling_criteria.delete_instance()
+                        scaling_policy.delete_instance()
+                    scaling_group.delete_instance()
+
+            except Exception as e:
+                log.exception("Error deleting scaling groups and alarms:")
+                tx.rollback()
+                raise e
+        database.db.close()
+
+    async def delete_orphaned_alarms(self, nsr_id):
+        database.db.connect()
+        with database.db.atomic() as tx:
+            try:
+                for scaling_group in ScalingGroup.select().where(ScalingGroup.nsr_id == nsr_id):
+                    for scaling_policy in scaling_group.scaling_policies:
+                        for scaling_criteria in scaling_policy.scaling_criterias:
+                            for alarm in scaling_criteria.scaling_alarms:
+                                try:
+                                    self.db_client.get_vdur(nsr_id, alarm.vnf_member_index, alarm.vdu_name)
+                                except VdurNotFound:
+                                    log.info("Deleting orphaned alarm %s", alarm.alarm_uuid)
+                                    try:
+                                        await self.mon_client.delete_alarm(
+                                            alarm.scaling_criteria.scaling_policy.scaling_group.nsr_id,
+                                            alarm.vnf_member_index,
+                                            alarm.vdu_name,
+                                            alarm.alarm_uuid)
+                                    except ValueError:
+                                        log.exception("Error deleting alarm in MON %s", alarm.alarm_uuid)
+                                    alarm.delete_instance()
+
+            except Exception as e:
+                log.exception("Error deleting orphaned alarms:")
+                tx.rollback()
+                raise e
+        database.db.close()
+
+    async def scale(self, alarm):
+        database.db.connect()
+        with database.db.atomic():
+            delta = datetime.datetime.now() - alarm.scaling_criteria.scaling_policy.last_scale
+            if delta.total_seconds() > alarm.scaling_criteria.scaling_policy.cooldown_time:
+                log.info("Sending scaling action message for ns: %s",
+                         alarm.scaling_criteria.scaling_policy.scaling_group.nsr_id)
+                await self.lcm_client.scale(alarm.scaling_criteria.scaling_policy.scaling_group.nsr_id,
+                                            alarm.scaling_criteria.scaling_policy.scaling_group.name,
+                                            alarm.vnf_member_index,
+                                            alarm.action)
+                alarm.scaling_criteria.scaling_policy.last_scale = datetime.datetime.now()
+                alarm.scaling_criteria.scaling_policy.save()
+            else:
+                log.info("Time between last scale and now is less than cooldown time. Skipping.")
+        database.db.close()
+
+    def get_alarm(self, alarm_uuid: str):
+        database.db.connect()
+        with database.db.atomic():
+            alarm = ScalingAlarm.select().where(ScalingAlarm.alarm_uuid == alarm_uuid).get()
+        database.db.close()
+        return alarm
+
+    def get_nslcmop(self, nslcmop_id):
+        return self.db_client.get_nslcmop(nslcmop_id)