如何以编程方式将lambda监听器规则注册到ALB？

Question

鉴于Cloudformation目前不支持ALB Lambda集成，我正在尝试编写一个简单的脚本来创建目标组，将lambda注册到目标组，然后将侦听器规则指向该目标组。

当我通过用户界面注册lambda目标时，这是有效的，但是我尝试将lambda目标注册到目标组的尝试失败了(在python脚本和cli中)：

botocore.exceptions.ClientError: An error occurred (AccessDenied) when calling the RegisterTargets operation: elasticloadbalancing principal does not have permission to invoke <LAMBDA ARN> from target group <TARGET GROUP ARN>

以下是执行此操作的python脚本：

import boto3
import os

environment = os.environ['ENV']
cloudformation = boto3.resource('cloudformation')
elb = boto3.client('elbv2')

stack = cloudformation.Stack('boomerang')

output = [x for x in stack.outputs if x['ExportName'] == 'boomerang-beacon-lambda'][0]
beacon_arn = output['OutputValue']

response = elb.create_target_group(
  TargetType='lambda',
  Name='public-%s-boomerang-beacon' % environment
)

target_group_arn = response['TargetGroups'][0]['TargetGroupArn']

elb.register_targets(
  TargetGroupArn=target_group_arn,
  Targets=[
    {
      'Id': beacon_arn
    },
  ]
)

谢谢

Answer 1

您必须创建一个添加lambda函数的权限，以允许弹性负载平衡主体调用您的lambda函数。使用CloudFormation，您可以添加以下资源以使其工作。

  LambdaFunctionPermission:
    Type: AWS::Lambda::Permission
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !GetAtt LambdaTargetFunction.Arn
      Principal: elasticloadbalancing.amazonaws.com
      SourceArn: !Ref TargetGroup

有关Lambda添加权限功能的更多信息可在此处找到：https://docs.aws.amazon.com/lambda/latest/dg/API_AddPermission.html

Answer 2

'''
Below function uses boto3 to add permission to lambda function and then register it to TargetGroup 
'''

def addLambdaPermission():
        clientLambda = boto3.client('lambda',aws_access_key_id=ACCESS_KEY,aws_secret_access_key=SECRET_KEY,region_name=REGION)
        response = clientLambda.add_permission(
                Action='lambda:InvokeFunction',
                FunctionName=lambda_name,
                Principal='elasticloadbalancing.amazonaws.com',
                StatementId='registerTargetPermission',
        )
        print('Permissions added')

addLambdaPermission()

response = client.register_targets(
    TargetGroupArn= TGArn,
    Targets=[
        {
            'Id': lambda_arn,
        },
    ],
)

print('Lambda registered with TG')