AWS Lambda（三）---用lambda和cloudwatch建立EBS Snapshots

2023-03-18 20:37:50

背景介紹：

lambda的功能，類似腳本，在lambda頁面添加trigger元件，意味着可以監聽這個元件的通知或者入參，然後調用lambda的代碼做事。

本文的例子是：lambda函數實作的功能是，給本region内的所有ec2做備份，也就是snapshot。

cloudwatch的作用是，監控某個元件的變化，監測到變化後可調用lambda做出相應的變動。這裡cloudwatch沒有監控别的元件，而是設定了一個定時任務，也就是每1分鐘或者2分鐘就通知lambda函數跑一邊代碼。本例子 rule a是1分鐘一次的定時任務，也就是一分鐘通知lambda跑一次。rule b是2分鐘跑一次。然後打開ec2頁面，檢視snapshot是否按照這個頻率變多。

1.建立一個lambda function，選擇python語言。在function code區域，内容寫為：

import json
import boto3

# Setting ec2 client.
ec2 = boto3.client('ec2')

# Our lambda handler function!
def lambda_handler(event, context):
    # Printing event received.
    # print("Received event: " + json.dumps(event, indent=2))

    # Let's go ahead and print the rule arn to the logs so we know they are different!
    rule_name = event['resources']
    print(rule_name)

    # Setting the variable to loop through later.
    # Filtering by only looking for 'in-use' EBS volumes.
    total_ebs = ec2.describe_volumes(Filters=[{'Name': 'status', 'Values': ['in-use']}])

    # Looping through and collecting all EBS volumes.
    for volume in total_ebs['Volumes']:
    	# Creating the snaphsot for all volumes within our region.
        ec2.create_snapshot(VolumeId=volume['VolumeId'],Description=volume['Attachments'][0]['InstanceId'])

        print("All done with volume: " + volume['VolumeId'])

頁面上方建立測試文本，測試内容寫為：

{
  "version": "0",
  "id": "89d1a02d-5ec7-412e-82f5-13505f849b41",
  "detail-type": "Scheduled Event",
  "source": "aws.events",
  "account": "123456789012",
  "time": "2016-12-30T18:44:49Z",
  "region": "us-east-1",
  "resources": [
    "arn:aws:events:us-east-1:123456789012:rule/LinuxAcademyRules"
  ],
  "detail": {}
}

具體步驟不會，可以參考https://blog.csdn.net/daiqinge/article/details/103283484

2. lambda的designer區域，增加一個trigger，選擇cloudwatch event, 然後點選頁面上方的save儲存。

3. 建立一個rule，起名為ruleA，其中schedule expression内容寫為： rate(1 minute)