AWS Lambda 函数代码

Code 是 AWS::Lambda::Function 资源的一个属性，可用来指定 AWS Lambda 函数的源代码。您的源代码可能位于 Amazon Simple Storage Service (Amazon S3) 存储桶内的模板或文件中。(仅限 nodejs4.3、nodejs6.10、python2.7 和 python3.6 运行时环境) 可以在模板中提供源代码作为内联文本。

语法

{
  "S3Bucket" : String,
  "S3Key" : String,
  "S3ObjectVersion" : String,
  "ZipFile" : String
}

S3Bucket: String
S3Key: String
S3ObjectVersion: String
ZipFile: String

属性

cfn-response 模块

当您使用 ZipFile 属性指定您的函数的源代码并且该函数与 AWS CloudFormation 自定义资源交互时，您可以加载 cfn-response 模块来发送响应到这些资源。该模块包含 send 方法，它以一种 Amazon S3 预签名 URL (ResponseURL) 的方式向自定义资源发送一个响应对象。

执行 send 方法之后，Lambda 函数终止，因此您在该方法之后写入的任何内容将忽略。

加载 cfn-response 模块

对于 nodejs4.3 或 nodejs6.10 运行时环境，可使用 require() 函数加载 cfn-response 模块。例如，以下代码示例创建一个名为 response 的 cfn-response 对象：

var response = require('cfn-response');

对于 python2.7 或 python3.6 环境，使用 import 语句加载 cfnresponse 模块，如下例所示：

import cfnresponse

send 方法参数

您可以将以下参数用于 send 方法。

示例

Node.js

在下面的 Node.js 示例中，内联 Lambda 函数获取输入值并将其乘以 5。内联函数对于较小的函数尤为有用，因为它们让您能够在模板中直接指定源代码，而不必先创建包再将包上传到 Amazon S3 存储桶中。函数使用 cfn-response send 方法将结果发回给调用此函数的自定义资源。

"ZipFile": { "Fn::Join": ["", [
  "var response = require('cfn-response');",
  "exports.handler = function(event, context) {",
  "  var input = parseInt(event.ResourceProperties.Input);",
  "  var responseData = {Value: input * 5};",
  "  response.send(event, context, response.SUCCESS, responseData);",
  "};"
]]}

ZipFile: >
  var response = require('cfn-response');
  exports.handler = function(event, context) {
    var input = parseInt(event.ResourceProperties.Input);
    var responseData = {Value: input * 5};
    response.send(event, context, response.SUCCESS, responseData);
  };

Python

和前例一样，在下面的 Python 示例中 (该示例适用于 2.7 和 3.6 版本)，内联 Lambda 函数接受一个整数值并将其乘以 5。

"ZipFile" : { "Fn::Join" : ["\n", [
  "import json",
  "import cfnresponse",
  "def handler(event, context):",
  "   responseValue = int(event['ResourceProperties']['Input']) * 5",
  "   responseData = {}",
  "   responseData['Data'] = responseValue",
  "   cfnresponse.send(event, context, cfnresponse.SUCCESS, responseData, \"CustomResourcePhysicalID\")"
]]}

ZipFile: |
  import json
  import cfnresponse
  def handler(event, context):
    responseValue = int(event['ResourceProperties']['Input']) * 5
    responseData = {}
    responseData['Data'] = responseValue
    cfnresponse.send(event, context, cfnresponse.SUCCESS, responseData, "CustomResourcePhysicalID")

模块源代码

以下为 nodejs4.3 或 nodejs6.10 运行时环境的响应模块源代码。请查看这些内容，以理解此模块的功能并帮助您实现自己的响应函数。

/* Copyright 2015 Amazon Web Services, Inc. or its affiliates. All Rights Reserved.
   This file is licensed to you under the AWS Customer Agreement (the "License").
   You may not use this file except in compliance with the License.
   A copy of the License is located at http://aws.amazon.com/agreement/ .
   This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied.
   See the License for the specific language governing permissions and limitations under the License. */

exports.SUCCESS = "SUCCESS";
exports.FAILED = "FAILED";

exports.send = function(event, context, responseStatus, responseData, physicalResourceId, noEcho) {

    var responseBody = JSON.stringify({
        Status: responseStatus,
        Reason: "See the details in CloudWatch Log Stream: " + context.logStreamName,
        PhysicalResourceId: physicalResourceId || context.logStreamName,
        StackId: event.StackId,
        RequestId: event.RequestId,
        LogicalResourceId: event.LogicalResourceId,
        NoEcho: noEcho || false,
        Data: responseData
    });

    console.log("Response body:\n", responseBody);

    var https = require("https");
    var url = require("url");

    var parsedUrl = url.parse(event.ResponseURL);
    var options = {
        hostname: parsedUrl.hostname,
        port: 443,
        path: parsedUrl.path,
        method: "PUT",
        headers: {
            "content-type": "",
            "content-length": responseBody.length
        }
    };

    var request = https.request(options, function(response) {
        console.log("Status code: " + response.statusCode);
        console.log("Status message: " + response.statusMessage);
        context.done();
    });

    request.on("error", function(error) {
        console.log("send(..) failed executing https.request(..): " + error);
        context.done();
    });

    request.write(responseBody);
    request.end();
}

以下是 python3.6 环境的响应模块源代码：

#  Copyright 2016 Amazon Web Services, Inc. or its affiliates. All Rights Reserved.
#  This file is licensed to you under the AWS Customer Agreement (the "License").
#  You may not use this file except in compliance with the License.
#  A copy of the License is located at http://aws.amazon.com/agreement/ .
#  This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied.
#  See the License for the specific language governing permissions and limitations under the License.

from botocore.vendored import requests
import json

SUCCESS = "SUCCESS"
FAILED = "FAILED"

def send(event, context, responseStatus, responseData, physicalResourceId=None, noEcho=False):
    responseUrl = event['ResponseURL']

    print(responseUrl)

    responseBody = {}
    responseBody['Status'] = responseStatus
    responseBody['Reason'] = 'See the details in CloudWatch Log Stream: ' + context.log_stream_name
    responseBody['PhysicalResourceId'] = physicalResourceId or context.log_stream_name
    responseBody['StackId'] = event['StackId']
    responseBody['RequestId'] = event['RequestId']
    responseBody['LogicalResourceId'] = event['LogicalResourceId']
    responseBody['NoEcho'] = noEcho
    responseBody['Data'] = responseData

    json_responseBody = json.dumps(responseBody)

    print("Response body:\n" + json_responseBody)

    headers = {
        'content-type' : '',
        'content-length' : str(len(json_responseBody))
    }

    try:
        response = requests.put(responseUrl,
                                data=json_responseBody,
                                headers=headers)
        print("Status code: " + response.reason)
    except Exception as e:
        print("send(..) failed executing requests.put(..): " + str(e))

以下是 python2.7 环境的响应模块源代码：

#  Copyright 2016 Amazon Web Services, Inc. or its affiliates. All Rights Reserved.
#  This file is licensed to you under the AWS Customer Agreement (the "License").
#  You may not use this file except in compliance with the License.
#  A copy of the License is located at http://aws.amazon.com/agreement/ .
#  This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied.
#  See the License for the specific language governing permissions and limitations under the License.

from botocore.vendored import requests
import json

SUCCESS = "SUCCESS"
FAILED = "FAILED"

def send(event, context, responseStatus, responseData, physicalResourceId=None, noEcho=False):
    responseUrl = event['ResponseURL']

    print responseUrl

    responseBody = {}
    responseBody['Status'] = responseStatus
    responseBody['Reason'] = 'See the details in CloudWatch Log Stream: ' + context.log_stream_name
    responseBody['PhysicalResourceId'] = physicalResourceId or context.log_stream_name
    responseBody['StackId'] = event['StackId']
    responseBody['RequestId'] = event['RequestId']
    responseBody['LogicalResourceId'] = event['LogicalResourceId']
    responseBody['NoEcho'] = noEcho
    responseBody['Data'] = responseData

    json_responseBody = json.dumps(responseBody)
   
    print "Response body:\n" + json_responseBody

    headers = {
        'content-type' : '', 
        'content-length' : str(len(json_responseBody))
    }
    
    try:
        response = requests.put(responseUrl,
                                data=json_responseBody,
                                headers=headers)
        print "Status code: " + response.reason
    except Exception as e:
        print "send(..) failed executing requests.put(..): " + str(e)

本页内容：

• 语法
• 属性
• cfn-response 模块