amazon-web-services - 用于 Lambda 的 AWS 状态机，cloudformation 语法

Question

我正在尝试提出一个 CloudFormation 模板，其中包括

• API 网关
• 通过 API 网关调用 StateMachine
• StateMachine 又包含一个 lambda 函数

本质上我想做的是以下

https://docs.aws.amazon.com/step-functions/latest/dg/tutorial-api-gateway.html

但是，我一直在想出将部署它的云形成模板(.yaml)。到目前为止，这就是我所拥有的

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Resources:
  Post:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: UserBase-fnUsers
      Handler: UsersHandler.getUsers
      Runtime: nodejs6.10
      Policies: [AmazonDynamoDBReadOnlyAccess, AmazonS3ReadOnlyAccess]
      Environment:
        Variables: 
          S3_BUCKET: UserBase-Users-bucket
          UsersTable: UserBase-Users-tblUsers
      Events:
        GetUsers:
          Type: Api
          Properties:
            Path: /UserBase/Users
            Method: post      
  Options:
    Type: AWS::Serverless::Function
    Properties:                     
      FunctionName: UserBase-fnUsers-Options
      Handler: UsersHandler.getOptions
      Runtime: nodejs6.10
      Events:
        GetOptions:
          Type: Api
          Properties:
            Path: /UserBase/Users
            Method: options                           
  UsersTable:
    Type: AWS::DynamoDB::Table
    Properties: 
      TableName: UserBase-Users-tblUsers
      AttributeDefinitions: 
        - AttributeName: Id
          AttributeType: S   
      KeySchema: 
        - AttributeName: Id
          KeyType: HASH   
      ProvisionedThroughput: 
        ReadCapacityUnits: 5
        WriteCapacityUnits: 5       
      StreamSpecification:
        StreamViewType: KEYS_ONLY                
  StatesExecutionRole:
    Type: "AWS::IAM::Role"
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: "Allow"
            Principal:
              Service:
                - !Sub states.${AWS::Region}.amazonaws.com
            Action: "sts:AssumeRole"
      Path: "/"
      Policies:
        - PolicyName: StatesExecutionPolicy
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
              - Effect: Allow
                Action:
                  - "lambda:InvokeFunction"
                Resource: "*"

  UpdateShoppingPath:
    Type: "AWS::StepFunctions::StateMachine"
    Properties:
      DefinitionString:
        !Sub
          - |-
            {
              "Comment": "State machine to update the shopping path",
              "StartAt": "UpdatePath",
              "States": {
                "UpdatePath": {
                  "Type": "Task",
                  "Resource": "${lambdaArn}",
                  "End": true
                }
              }
            }
          - {lambdaArn: !GetAtt [ Post, Arn ]}
      RoleArn: !GetAtt [ StatesExecutionRole, Arn ]
  UserBaseUsers:
     Type: "AWS::ApiGateway::Resource"

我被最后一部分困住了，主要是关于如何将 ApiGateway 链接到 StateMachine。顺便说一句，我有什么方法可以从 AWS 中的现有部署生成云形成模板(.yaml 或 json)吗？

Answer 1

我不是 yaml 方面的专家，但我使用 json CloudFormation 做了一些配置，据我所知，它很容易翻译。

过去我也像你一样陷入困境，并且here这是我的帖子和我的解决方案

要开始执行 Step Functions，您需要做的是将 HTTP Post 发送到作为 json 对象传递的 arn:aws:apigateway:${region}:states:action/StartExecution [docs] :

{
input: __input__,
stateMachineArn: __arn__
}

简而言之，在您的 AWS::ApiGateway::Method 中，您必须将 HTTP 集成设置为 arn:aws:apigateway:${region}:states:action/StartExecution 和一个构建我提到的 json 对象的 requestTemplate。

作为引用，这里是我的 json cloudformation 示例:

"FooRequest": {
    "DependsOn": ["FooStepMachine"],
    "Type": "AWS::ApiGateway::Method",
    "Properties": {
        "HttpMethod": "POST",
        "Integration": {
            "Type": "AWS",
            "Credentials": {
                "Fn::GetAtt": ["FooRole",
                "Arn"]
            },
            "IntegrationHttpMethod": "POST",
            "Uri": {
                "Fn::Join": ["",
                ["arn:aws:apigateway:",
                {
                    "Ref": "AWS::Region"
                },
                ":states:action/StartExecution"]]
            },
            "IntegrationResponses": [{
                "StatusCode": 200
            },
            {
                "StatusCode": 401
            }],
            "RequestTemplates": {
                "application/json": {
                    "Fn::Sub": ["{\"input\": \"$util.escapeJavaScript($input.json('$'))\",\"stateMachineArn\": \"${arn}\"}",
                    {
                        "arn": {
                            "Ref": "FooStepMachine"
                        }
                    }]
                }
            }
        }
    }
}