CloudMonitoringTriggerFunctionCalculation

CloudMonitor

CloudMonitor provides end-to-end, out-of-the-box, and enterprise-class monitoring solutions for cloud users. CloudMonitor is able to monitor IT infrastructure, external network quality, events, custom metrics, and service logs, and provides you with efficient, comprehensive, and cost-effective monitoring services.

CloudMonitor provides the cloud service events monitoring feature, and more events are being added to this feature. Custom processing of cloud resources can be automatically performed when multiple events trigger custom functions.

Scenario

If an ECS instance is restarted due to system errors, you may need to verify the problem or create snapshots. In this example, you can trigger a function through CloudMonitor to automatically process the instance that is restarted due to system or instance errors. For example, snapshots are automatically created after the instance is restarted.

Preparation

ECS system events

Cloud service events monitoring

Function code

The following code indicates that a restart event of an ECS instance triggers the function. The function locates the cloud disks that are attached to the instance and creates snapshots for the cloud disks.

# -*- coding: utf-8 -*-
import logging
import json, random, string, time
from aliyunsdkcore import client
from aliyunsdkecs.request.v20140526.DeleteSnapshotRequest import DeleteSnapshotRequest
from aliyunsdkecs.request.v20140526.CreateSnapshotRequest import CreateSnapshotRequest
from aliyunsdkecs.request.v20140526.DescribeDisksRequest import DescribeDisksRequest
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:12345678: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");
  name = name.lower()
  if name in [ 'Instance:SystemFailure.Reboot:Executing'.lower(), "Instance:InstanceFailure.Reboot:Executing".lower()]:
    pass
    # do other things
  if name in ['Instance:SystemFailure.Reboot:Executed'.lower(), "Instance:InstanceFailure.Reboot:Executed".lower()]:
    request = DescribeDisksRequest()
    request.add_query_param("RegionId", "cn-shenzhen")
    request.set_InstanceId(ecsInstanceId)
    response = _send_request(request)
    disks = response.get('Disks').get('Disk', [])
    for disk in disks:
      diskId = disk["DiskId"]
      SnapshotId = create_ecs_snap_by_id(diskId)
      LOGGER.info("Create ecs snap sucess, ecs id = %s , disk id = %s ", ecsInstanceId, diskId)
def create_ecs_snap_by_id(disk_id):
    LOGGER.info("Create ecs snap, disk id is %s ", disk_id)
    request = CreateSnapshotRequest()
    request.set_DiskId(disk_id)
    request.set_SnapshotName("reboot_" + ''.join(random.choice(string.ascii_lowercase) for _ in range(6)))
    response = _send_request(request)
    return response.get("SnapshotId")
# 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)

Procedure

• Create the function by using the code at the end of this topic. For more information about creating a function, see the Hello World topic in Function Compute documentation.

Note: You must grant the operating permissions on ECS instances to the service role.

• Log on to the CloudMonitor console. In the left-side navigation pane, click Event Monitoring, and click the Alarm Rules tab. On the Alarm Rules tab, click Create Event Alert in the upper-right corner. Configure the parameters on the Create/Modify Event Alert page as shown in the following figure.

• Simulate debugging.

• Simulate an ECS event.For more information, see Simulating the process of handling system events.