AWS Step Function状态机定义报错及CF转HCL/JSON工具咨询

一、错误逐一修复说明 #

所有报错均为不符合Amazon States Language语法规范导致，对应修复逻辑如下：

• Retry/Catch/Choices字段要求为数组格式：现有定义中以上字段均为单个对象，需用方括号包裹改为对象数组，例如"Retry": { ... }修改为"Retry": [ { ... } ]
• End字段要求为布尔值：现有定义中写为字符串格式"End": "True"/"End": "true"，需去掉引号改为"End": true
• ResultPath若需要丢弃结果，不能写字符串"null"，需改为JSON原生null值，即"ResultPath": null
• 数值类字段需去掉引号：IntervalSeconds、MaxAttempts、BackoffRate、NumericEquals为数字类型，现有定义加了双引号变为字符串，删除引号即可
• 完成上述语法修复后，MISSING_END_STATE、Iterator不可达的报错会自动消失，两类报错是前置语法错误导致的解析异常误报

二、修复后的完整状态机JSON定义 #

{
   "StartAt":"StartState",
   "States":{
      "StartState":{
         "Type":"Pass",
         "Next":"GetLastExecutionDateTime"
      },
      "GetLastExecutionDateTime":{
         "Type":"Task",
         "Parameters":{
            "Payload.$":"$"
         },
         "Resource":"${aws_lambda_function.read.arn}",
         "Retry":[{
            "ErrorEquals":[
               "States.ALL"
            ],
            "IntervalSeconds":2,
            "MaxAttempts":1,
            "BackoffRate":2
         }],
         "Next":"GetDeltaRecordsNumber",
         "ResultPath":"$.lastExecutedDateTime",
         "OutputPath":"$.lastExecutedDateTime.Payload"
      },
      "GetDeltaRecordsNumber":{
         "Type":"Task",
         "Parameters":{
            "Payload.$":"$"
         },
         "Resource":"${aws_lambda_function.count.arn}",
         "Retry":[{
            "ErrorEquals":[
               "States.ALL"
            ],
            "IntervalSeconds":2,
            "MaxAttempts":6,
            "BackoffRate":2
         }],
         "Next":"DeltaRecordsNumber",
         "ResultPath":"$.Payload"
      },
      "DeltaRecordsNumber":{
         "Type":"Choice",
         "Choices":[{
            "Variable":"$.Payload.Payload.totalRows",
            "NumericEquals":0,
            "Next":"EndState"
         }],
         "Default":"Iterator"
      },
      "Iterator":{
         "Type":"Map",
         "Next":"PassNewExecutionDateTime",
         "Iterator":{
            "StartAt":"ExecuteSqlQuery",
            "States":{
               "ExecuteSqlQuery":{
                  "Type":"Task",
                  "Resource":"${aws_lambda_function.query.arn}",
                  "OutputPath":"$.Payload",
                  "Parameters":{
                     "Payload.$":"$"
                  },
                  "End":true
               }
            }
         },
         "ItemsPath":"$.Payload.Payload.iterations",
         "Retry":[{
            "ErrorEquals":[
               "States.ALL"
            ],
            "IntervalSeconds":1,
            "MaxAttempts":1,
            "BackoffRate":1
         }],
         "Catch":[{
            "ErrorEquals":[
               "States.ALL"
            ],
            "Next":"EndState",
            "ResultPath":"$.Payload"
         }],
         "ResultPath":null
      },
      "PassNewExecutionDateTime":{
         "Type":"Pass",
         "Next":"StoreNewExecutionDateTIme",
         "OutputPath":"$.Payload.Payload"
      },
      "StoreNewExecutionDateTIme":{
         "Type":"Task",
         "Resource":"${aws_lambda_function.write.arn}",
         "OutputPath":"$.Payload",
         "Parameters":{
            "Payload.$":"$"
         },
         "Retry":[{
            "ErrorEquals":[
               "States.ALL"
            ],
            "IntervalSeconds":2,
            "MaxAttempts":1,
            "BackoffRate":2
         }],
         "Next":"EndState"
      },
      "EndState":{
         "Type":"Pass",
         "End":true
      }
   }
}

三、CloudFormation格式Step Function定义转HCL/JSON方案 #

无需额外工具，CloudFormation中的Step Function定义本身就是标准ASL JSON格式，直接复制定义内容，将其中CloudFormation的变量引用规则替换为Terraform的插值变量规则，即可直接嵌入到Terraform的aws_sfn_state_machine资源的definition参数中使用。

内容的提问来源于stack exchange，提问作者Xcute