在对流层中添加对现有 sns 主题的订阅答案

【问题标题】：Adding a subscription to an existing sns topic in troposphere在对流层中添加对现有 sns 主题的订阅
【发布时间】：2019-12-13 05:37:28
【问题描述】：

我有一个用例，其中我有一个现有的 sns 主题，我正在使用 cloudformation 和 troposphere 创建 lambda 函数。我必须以某种方式创建我的堆栈，使主题向我的 lambda 函数发送订阅，但不应重新创建主题本身。

下面是我的代码：

from troposphere import FindInMap, GetAtt, Join, Output
from troposphere import Template, Ref
from troposphere.awslambda import Function, Code, Permission
from troposphere.sns import Topic, SubscriptionResource

folder_names = ["welt", "jukin"]

t = Template()

t.set_version("2010-09-09")

t.add_mapping("MapperToTenantId",
              {
                  u'welt': {'id': u't-012'},
                  u'jukin': {'id': u't-007'}
              }
              )

t.add_mapping("LambdaExecutionRole",
                {u'lambda-execution-role': {u'ARN': u'arn:aws:iam::498129003450:role/service-role/lambda_execution_role'}}
            )

code = [
    "def lambda_handler(event, context):\n",
    "    message = event[‘Records’][0][‘Sns’][‘Message’]\n",
    "    print(“From SNS: “ + message)\n",
    "    return message\n"
]


for cp in folder_names:
    lambda_function = t.add_resource(Function(
        f"{cp}MapperLambda",
        Code=Code(
        ZipFile=Join("", code)
    ),
    Handler="index.handler",
    Role=FindInMap("LambdaExecutionRole", "lambda-execution-role", "ARN"),
    Runtime="python3.6",
    )
    )

    t.add_resource(Permission(
        f"InvokeLambda{cp}Permission",
        FunctionName=GetAtt(lambda_function, "Arn"),
        Action="lambda:InvokeFunction",
        SourceArn='arn:aws:sns:us-west-2:498129003450:IngestStateTopic',
        Principal="sns.amazonaws.com"
    ))

    t.add_resource(SubscriptionResource(
        EndPoint=GetAtt(lambda_function, "Arn"),
        Protocol='lambda',
        TopicArn='arn:aws:sns:us-west-2:498129003450:IngestStateTopic'
    ))



with open('mapper_cf.yaml', 'w') as y:
    y.write(t.to_yaml())

我收到以下错误，我无法找到出路：

Traceback (most recent call last):
  File "create_cloudformation.py", line 54, in <module>
    TopicArn='arn:aws:sns:us-west-2:498129003450:IngestStateTopic'
TypeError: __init__() missing 1 required positional argument: 'title'

这可能在对流层中进行吗？我不想硬编码云形成中的块，但我想在对流层中生成它。

这有可能吗？

请给我一些提示。

【问题讨论】：

标签： python amazon-cloudformation troposphere

【解决方案1】：

您遇到的错误与未指定标题字符串有关。试试这个：

t.add_resource(SubscriptionResource(
    f"{cp}Subscription",
    EndPoint=GetAtt(lambda_function, "Arn"),
    Protocol='lambda',
    TopicArn='arn:aws:sns:us-west-2:498129003450:IngestStateTopic'
))

【讨论】：