AWS Lambda：“参数验证失败”答案

【问题标题】：AWS Lambda : "Parameter validation failed"AWS Lambda：“参数验证失败”
【发布时间】：2019-07-24 18:55:57
【问题描述】：

我有一个 lambda 函数，我在其中发送电子邮件，邮件模板作为对象从 S3 存储桶中提取。我已经在我的计算机上本地运行了代码，并且工作正常。当我将它粘贴到我的 lambda 函数中时，它显示以下错误。

Response:
{
  "errorMessage": "Parameter validation failed:\nInvalid type for parameter Message.Body.Html.Data, value: b\"<html>\\n<head></head>\\n<body>\\n  <h1>Amazon SES Test (SDK for Python)</h1>\\n  <p>This email was sent with\\n    <a href='https://aws.amazon.com/ses/'>Amazon SES</a> using the\\n    <a href='https://aws.amazon.com/sdk-for-python/'>\\n      AWS SDK for Python (Boto)</a>.</p>\\n</body>\\n</html>\", type: <class 'bytes'>, valid types: <class 'str'>",
  "errorType": "ParamValidationError",
  "stackTrace": [
    [
      "/var/task/lambda_function.py",
      65,
      "lambda_handler",
      "Source=SENDER,"
    ],
    [
      "/var/runtime/botocore/client.py",
      314,
      "_api_call",
      "return self._make_api_call(operation_name, kwargs)"
    ],
    [
      "/var/runtime/botocore/client.py",
      586,
      "_make_api_call",
      "api_params, operation_model, context=request_context)"
    ],
    [
      "/var/runtime/botocore/client.py",
      621,
      "_convert_to_request_dict",
      "api_params, operation_model)"
    ],
    [
      "/var/runtime/botocore/validate.py",
      291,
      "serialize_to_request",
      "raise ParamValidationError(report=report.generate_report())"
    ]
  ]
}

Request ID:
"7b13a612-97f6-4278-9825-724abeaa3b51"

Function Logs:
START RequestId: 7b13a612-97f6-4278-9825-724abeaa3b51 Version: $LATEST
Parameter validation failed:
Invalid type for parameter Message.Body.Html.Data, value: b"<html>\n<head></head>\n<body>\n  <h1>Amazon SES Test (SDK for Python)</h1>\n  <p>This email was sent with\n    <a href='https://aws.amazon.com/ses/'>Amazon SES</a> using the\n    <a href='https://aws.amazon.com/sdk-for-python/'>\n      AWS SDK for Python (Boto)</a>.</p>\n</body>\n</html>", type: <class 'bytes'>, valid types: <class 'str'>: ParamValidationError
Traceback (most recent call last):
  File "/var/task/lambda_function.py", line 65, in lambda_handler
    Source=SENDER,
  File "/var/runtime/botocore/client.py", line 314, in _api_call
    return self._make_api_call(operation_name, kwargs)
  File "/var/runtime/botocore/client.py", line 586, in _make_api_call
    api_params, operation_model, context=request_context)
  File "/var/runtime/botocore/client.py", line 621, in _convert_to_request_dict
    api_params, operation_model)
  File "/var/runtime/botocore/validate.py", line 291, in serialize_to_request
    raise ParamValidationError(report=report.generate_report())
botocore.exceptions.ParamValidationError: Parameter validation failed:
Invalid type for parameter Message.Body.Html.Data, value: b"<html>\n<head></head>\n<body>\n  <h1>Amazon SES Test (SDK for Python)</h1>\n  <p>This email was sent with\n    <a href='https://aws.amazon.com/ses/'>Amazon SES</a> using the\n    <a href='https://aws.amazon.com/sdk-for-python/'>\n      AWS SDK for Python (Boto)</a>.</p>\n</body>\n</html>", type: <class 'bytes'>, valid types: <class 'str'>

END RequestId: 7b13a612-97f6-4278-9825-724abeaa3b51
REPORT RequestId: 7b13a612-97f6-4278-9825-724abeaa3b51  Duration: 1608.47 ms    Billed Duration: 1700 ms    Memory Size: 128 MB Max Memory Used: 71 MB

当我从 S3 存储桶加载模板时，我已检查它在 lambda 中显示以下错误。当我在我的代码中声明 BODY_HTML 而不是从 Lambda 中的 S3 获取它时，它工作正常。这是我现在的代码：

import json
import os
import boto3
from botocore.exceptions import ClientError

SENDER = "***********"
RECIPIENT = "************"
AWS_REGION = "us-east-1"
def lambda_handler(event, context):            
    CHARSET = "UTF-8"
    client = boto3.client('ses',aws_access_key_id=******,
                              aws_secret_access_key=*****,region_name='us-east-1')
    s3_client = boto3.client('s3',aws_access_key_id=*********,
                                  aws_secret_access_key=***********,region_name='us-east-1')
    s3_response_object = s3_client.get_object(Bucket='my s3 bucket', Key='template.html')
    object_content = s3_response_object['Body'].read()
    BODY_HTML = object_content
    SUBJECT = "sqs-poc-lambda test email"
    BODY_TEXT = ("This is a test email for sqs-poc-lambda"
                )

    try:
        #Provide the contents of the email.
        response = client.send_email(
            Destination={
                'ToAddresses': [
                    RECIPIENT,
                ],
            },
            Message={
                'Body': {
                    'Html': {
                        'Charset': CHARSET,
                        'Data': BODY_HTML,
                    },
                    'Text': {
                        'Charset': CHARSET,
                        'Data': BODY_TEXT,
                    },
                },
                'Subject': {
                    'Charset': CHARSET,
                    'Data': SUBJECT,
                },
            },
            Source=SENDER,
        )

    except ClientError as e:
        print(e.response['Error']['Message'])
    else:
        print("Email sent! Message ID:"),
        print(response['MessageId'])

)

它应该在Function Logs 中成功返回消息ID。对此有什么帮助吗？我看不出这背后有什么逻辑。

【问题讨论】：

在代码中使用access_keys 是一种不好的做法，请尝试使用角色。

标签： python amazon-web-services aws-lambda boto3

【解决方案1】：

很难相信第二个代码有效，因为它包含与第一个错误日志中报告的相同的错误。我复制了代码，它以同样的方式失败。

可以通过从错误日志中读取此消息来发现问题。

参数Message.Body.Html.Data的类型无效，值：b“...”，类型：类字节，有效类型：类'str'：ParamValidationError。

正文应该是字符串类型但object_content

object_content = s3_response['Body'].read()

是字节类型。您需要将其转换为字符串。例如。 BODY_HTML = str(object_content)

重要

不在您的 lambda 代码中存储永久凭据。

client = boto3.client('ses',aws_access_key_id=******,
                          aws_secret_access_key=*****,region_name='us-east-1')
s3_client = boto3.client('s3',aws_access_key_id=*********,
                          aws_secret_access_key=***********,region_name='us-east-1')

通过 Lambda 执行角色授予对您的 lambda 函数的权限。

如果您需要为您的 lambda 函数提供跨账户访问权限，则在该角色中包含 sts:AssumeRole 权限，然后使用通过调用 sts:AssumeRole 获得的临时凭据

client = boto3.client(
    'ses',
    aws_access_key_id=...,
    aws_secret_access_key=...,
    aws_session_token=... // !!!
)

但同样，绝不在您的函数代码中存储永久凭据。您确定下次将代码放入某个公共存储库时不会忘记将这些值替换为******？每次？

【讨论】：

谢谢马图斯。我刚刚开始使用 AWS 服务，我真的通过替换 ***** 将它们上传到开源。