函數計算自動化運維實戰 2 -- 事件觸發 eip 自動轉移

函數計算

阿里云函數計算是一個事件驅動的全托管計算服務。通過函數計算，您無需管理服務器等基礎設施，只需編寫代碼并上傳。函數計算會為您準備好計算資源，以彈性、可靠的方式運行您的代碼，并提供日志查詢，性能監控，報警等功能。借助于函數計算，您可以快速構建任何類型的應用和服務，無需管理和運維。更棒的是，您只需要為代碼實際運行消耗的資源付費，而代碼未運行則不產生費用。

云監控

阿里云云監控為云上用戶提供開箱即用的企業級開放型一站式監控解決方案。涵蓋 IT 設施基礎監控，外網網絡質量撥測監控，基于事件、自定義指標、日志的業務監控。為您全方位提供更高效、更全面、更省錢的監控服務。

云監控提供了豐富事件，并且事件還在不斷豐富中（云產品系統事件監控）， 豐富的事件觸發自定義處理的函數，可以實現更加完美的的自動化運維。

專題傳送門 => 函數計算進行自動化運維專題

示例場景

假設兩臺 ECS 機器A, B, A 機器出現了宕機，這個時候需要把 A 機器上的 eip 遷移到備用機器 B 上，這個利用云監控的報警和函數計算可以實現EIP的自動遷移， 云監控檢測到 A 宕機這個事件，然后觸發函數執行，函數實現 eip 的自動遷移

操作步驟

• 創建函數(函數代碼在文末),函數創建可參考函數計算helloworld

  注：記得給函數的 service 的 role 設置操作 ecs 和 eip 的權限
  cdn.com/969096ef4233ea658e1ccf75686a7c4620269329.png">

• 登錄云監控控制臺, 創建報警規則, 監控的事件為 ecs 重啟開始

• mock調試

• 模擬真實的 ecs 事件

• 請參考演練系統事件處理程序？ So Easy~

代碼

# -*- coding: utf-8 -*-
import logging
import json, random, string, time
from aliyunsdkcore import client
from aliyunsdkvpc.request.v20160428.AssociateEipAddre***equest import AssociateEipAddre***equest
from aliyunsdkvpc.request.v20160428.UnassociateEipAddre***equest import UnassociateEipAddre***equest
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 = UnassociateEipAddre***equest()
  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 = AssociateEipAddre***equest()
  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)

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