AWS SAM中能否配置多Lambda处理不同POST请求？配置是否正确？

我正在使用Visual Studio 2022构建AWS Serverless Application Model (SAM)应用，通过Functions.cs定义多个Lambda函数供外部Web应用调用。想请教两个问题：

1. 是否可以定义多个Lambda函数来处理不同类型的POST请求？
2. 是不是每个HTTP动词（如POST、GET、PUT等）只能对应一个函数？

以下是我的serverless.template文件片段（敏感信息已模糊处理），里面声明了两个POST函数，请问这样的定义是否正确，是否需要修改？

"ListCertificates": {
  "Type": "AWS::Serverless::Function",
  "Properties": {
    "Architectures": [
      "x86_64"
    ],
    "Handler": "xxx.xxx.xxx.POC.AWS::xxx.xxx.xxx.POC.AWS.Functions::Post",
    "Runtime": "dotnet6",
    "CodeUri": "",
    "MemorySize": 256,
    "Timeout": 30,
    "Role": null,
    "Policies": [
      "AWSLambdaBasicExecutionRole"
    ],
    "Environment": {
      "Variables": {
        "POWERTOOLS_SERVICE_NAME": "CertificateManagement",
        "POWERTOOLS_LOG_LEVEL": "Info",
        "POWERTOOLS_LOGGER_CASE": "PascalCase",
        "POWERTOOLS_TRACER_CAPTURE_RESPONSE": true,
        "POWERTOOLS_TRACER_CAPTURE_ERROR": true,
        "POWERTOOLS_METRICS_NAMESPACE": "ListCertificatesFunction"
      }
    },
    "Events": {
      "RootPost": {
        "Type": "Api",
        "Properties": {
          "Path": "/",
          "Method": "POST"
        }
      }
    }
  }
},
"UploadCertificate": {
  "Type": "AWS::Serverless::Function",
  "Properties": {
    "Architectures": [
      "x86_64"
    ],
    "Handler": "xxx.xxx.xxx.POC.AWS::xxx.xxx.xxx.POC.AWS.Functions::Post",
    "Runtime": "dotnet6",
    "CodeUri": "",
    "MemorySize": 256,
    "Timeout": 30,
    "Role": null,
    "Policies": [
      "AWSLambdaBasicExecutionRole"
    ],
    "Environment": {
      "Variables": {
        "POWERTOOLS_SERVICE_NAME": "CertificateManagement",
        "POWERTOOLS_LOG_LEVEL": "Info",
        "POWERTOOLS_LOGGER_CASE": "PascalCase",
        "POWERTOOLS_TRACER_CAPTURE_RESPONSE": true,
        "POWERTOOLS_TRACER_CAPTURE_ERROR": true,
        "POWERTOOLS_METRICS_NAMESPACE": "UploadCertificateFunction"
      }
    },
    "Events": {
      "RootPost": {
        "Type": "Api",
        "Properties": {
          "Path": "/",
          "Method": "POST"
        }
      }
    }
  }
}

1. 完全可以用多个Lambda函数处理不同类型的POST请求，HTTP动词和Lambda函数的数量没有绑定限制，你可以根据业务逻辑拆分多个函数分别处理不同场景的POST请求。

2. 当前的模板定义存在问题，需要修改：

   • 两个函数都绑定到了同一个路径/和POST方法，API Gateway无法区分请求应该转发给哪个函数，会导致路由冲突，部署后可能出现随机触发其中一个函数或者报错的情况。
   • 另外两个函数的Handler都指向同一个Functions::Post方法，就算路由没问题，触发后执行的也是同一段逻辑，达不到区分处理的目的。

3. 修改建议：

   • 区分路由路径：给两个函数设置不同的API路径，符合RESTful设计，比如：
     • ListCertificates函数绑定路径/list-certificates，POST方法
     • UploadCertificate函数绑定路径/upload-certificate，POST方法
   • 拆分处理方法：在Functions.cs中分别定义两个不同的处理方法，比如PostListCertificates和PostUploadCertificate，然后对应修改每个函数的Handler配置。

修正后的模板片段示例：

"ListCertificates": {
  "Type": "AWS::Serverless::Function",
  "Properties": {
    "Architectures": [
      "x86_64"
    ],
    "Handler": "xxx.xxx.xxx.POC.AWS::xxx.xxx.xxx.POC.AWS.Functions::PostListCertificates",
    "Runtime": "dotnet6",
    "CodeUri": "",
    "MemorySize": 256,
    "Timeout": 30,
    "Role": null,
    "Policies": [
      "AWSLambdaBasicExecutionRole"
    ],
    "Environment": {
      "Variables": {
        "POWERTOOLS_SERVICE_NAME": "CertificateManagement",
        "POWERTOOLS_LOG_LEVEL": "Info",
        "POWERTOOLS_LOGGER_CASE": "PascalCase",
        "POWERTOOLS_TRACER_CAPTURE_RESPONSE": true,
        "POWERTOOLS_TRACER_CAPTURE_ERROR": true,
        "POWERTOOLS_METRICS_NAMESPACE": "ListCertificatesFunction"
      }
    },
    "Events": {
      "ListCertificatesPost": {
        "Type": "Api",
        "Properties": {
          "Path": "/list-certificates",
          "Method": "POST"
        }
      }
    }
  }
},
"UploadCertificate": {
  "Type": "AWS::Serverless::Function",
  "Properties": {
    "Architectures": [
      "x86_64"
    ],
    "Handler": "xxx.xxx.xxx.POC.AWS::xxx.xxx.xxx.POC.AWS.Functions::PostUploadCertificate",
    "Runtime": "dotnet6",
    "CodeUri": "",
    "MemorySize": 256,
    "Timeout": 30,
    "Role": null,
    "Policies": [
      "AWSLambdaBasicExecutionRole"
    ],
    "Environment": {
      "Variables": {
        "POWERTOOLS_SERVICE_NAME": "CertificateManagement",
        "POWERTOOLS_LOG_LEVEL": "Info",
        "POWERTOOLS_LOGGER_CASE": "PascalCase",
        "POWERTOOLS_TRACER_CAPTURE_RESPONSE": true,
        "POWERTOOLS_TRACER_CAPTURE_ERROR": true,
        "POWERTOOLS_METRICS_NAMESPACE": "UploadCertificateFunction"
      }
    },
    "Events": {
      "UploadCertificatePost": {
        "Type": "Api",
        "Properties": {
          "Path": "/upload-certificate",
          "Method": "POST"
        }
      }
    }
  }
}

内容的提问来源于stack exchange，提问作者CB_at_Sw