Ali cloud Function calculation Is an event driven fully hosted computing service. Through function calculation, you don't need to manage infrastructure such as servers, just write code and upload it. Function calculation will prepare computing resources for you, run your code in a flexible and reliable way, and provide log query, performance monitoring, alarm and other functions. With function computing, you can quickly build any type of application and service without management and operation and maintenance. What's better, you only need to pay for the resources consumed by the actual running of the code, while there is no cost for the code not running.
Cloud monitoringAli cloud Cloud monitoring Provide an enterprise level open one-stop monitoring solution for cloud users out of the box. IT covers IT infrastructure monitoring, external network quality dial-up monitoring, business monitoring based on events, custom indicators and logs. To provide you with a more efficient, comprehensive and cost-effective monitoring service. < br / > cloud monitoring provides rich events, which are still in the process of enrichment( Event monitoring of cloud product system ), rich event trigger user-defined processing functions can achieve more perfect automatic operation and maintenance.
Thematic portal = > Function calculation for automatic operation and maintenance
Example scenarioSuppose that two ECS machines A, B and A are down. At this time, EIP on machine A needs to be migrated to standby machine B. This can realize the automatic migration of EIP by using the alarm and function calculation of cloud monitoring. Cloud monitoring detects the event of A down, and then triggers the function execution. The function realizes the automatic migration of EIP
Operation steps- Create a function (the function code is at the end of the article). For function creation, please refer to Function calculation helloworld
Note: remember to set the permissions to operate ecs and eip for the role of the function's service 
- Sign in Cloud monitoring console , create an alarm rule, and the monitored event is the start of ecs restart
- mock debugging
- Simulate real ecs events < br / > please refer to Drill system event handler? So Easy~
Code
# -*- coding: utf-8 -*- import logging import json, random, string, time from aliyunsdkcore import client from aliyunsdkvpc.request.v20160428.AssociateEipAddressRequest import AssociateEipAddressRequest from aliyunsdkvpc.request.v20160428.UnassociateEipAddressRequest import UnassociateEipAddressRequest from aliyunsdkvpc.request.v20160428.DescribeEipAddressesRequest import DescribeEipAddressesRequest from aliyunsdkcore.auth.credentials import StsTokenCredential LOGGER = logging.getLogger() clt = None def handler(event, context): creds = context.credentials sts_token_credential = StsTokenCredential(creds.access_key_id, creds.access_key_secret, creds.security_token) ''' { "product": "ECS", "content": { "executeFinishTime": "2018-06-08T01:25:37Z", "executeStartTime": "2018-06-08T01:23:37Z", "ecsInstanceName": "timewarp", "eventId": "e-t4nhcpqcu8fqushpn3mm", "eventType": "InstanceFailure.Reboot", "ecsInstanceId": "i-bp18l0uopocfc98xxxx" }, "resourceId": "acs:ecs:cn-hangzhou:123456789:instance/i-bp18l0uopocfc98xxxx", "level": "CRITICAL", "instanceName": "instanceName", "status": "Executing", "name": "Instance:SystemFailure.Reboot:Executing", "regionId": "cn-hangzhou" } ''' evt = json.loads(event) content = evt.get("content"); ecsInstanceId = content.get("ecsInstanceId"); regionId = evt.get("regionId"); global clt clt = client.AcsClient(region_id=regionId, credential=sts_token_credential) name = evt.get("name"); eipId = "eip-bp1nexxxc7zjfnex6i0"; standbyEcsId = "i-bp19yycxx7yroukxpv" name = name.lower() if name in ['Disk:Stalled:Executing'.lower(), 'Instance:SystemFailure.Reboot:Executing'.lower(), "Instance:InstanceFailure.Reboot:Executing".lower()]: print("move eip to standbyEcs"); move_eip(ecsInstanceId, standbyEcsId, eipId) # move eip to standbyEcs else: # other event to do pass def getEipStatus(eip): request = DescribeEipAddressesRequest() request.set_AllocationId(eip) request.add_query_param("RegionId", "cn-hangzhou") response = _send_request(request) if isinstance(response, dict) and "RequestId" in response: EipAddresses = response.get('EipAddresses', {}) EipAddress = EipAddresses['EipAddress'][0] status = EipAddress['Status'] return status else: LOGGER.error("getEipAddressDesc {} fail".format(eip)) def unAssociateEip(ecs_id, eip): request = UnassociateEipAddressRequest() request.set_AllocationId(eip) request.set_InstanceType('EcsInstance') request.set_InstanceId(ecs_id) response = _send_request(request) if isinstance(response, dict) and "RequestId" in response: LOGGER.info("UnassociateEipAddress {} from {} succ".format(ecs_id, eip)) else: LOGGER.error("UnassociateEipAddress {} from {} fail".format(ecs_id, eip)) def associateEip(ecs_id, eip): associte_request = AssociateEipAddressRequest() associte_request.set_AllocationId(eip) associte_request.set_InstanceType('EcsInstance') associte_request.set_InstanceId(ecs_id) associte_response = _send_request(associte_request) if isinstance(associte_response, dict) and "RequestId" in associte_response: LOGGER.info("AssociateEipAddress {} to {} succ".format(eip, ecs_id)) return True return False def move_eip(from_ecs, to_ecs, eip): unAssociateEip(from_ecs, eip) # wait unAssociateEip ... time.sleep(3) # retry 30s util sucess for i in xrange(10): eip_status = getEipStatus(eip).lower() if eip_status == 'available': if associateEip(to_ecs, eip): LOGGER.info("AssociateEipAddress {} to {} succ".format(eip, to_ecs)) return else: LOGGER.info("eip status = {}".format(eip_status)) time.sleep(3) LOGGER.info("AssociateEipAddress {} to {} fail".format(eip, to_ecs)) # send open api request def _send_request(request): request.set_accept_format('json') try: response_str = clt.do_action_with_exception(request) LOGGER.info(response_str) response_detail = json.loads(response_str) return response_detail except Exception as e: LOGGER.error(e)