ネストしたjsonをjq で辿る

a.jq

..    # 再帰的に辿る
| objects   # object のみに絞る
| to_entries[]   # key, value を分離
| select(.value.Type? == "Task")   # 'Type' キーが存在する && その値が "Task" ものだけ抽出

Makefile

# サンプルはこちらにある json
# https://docs.aws.amazon.com/ja_jp/step-functions/latest/dg/sample-map-state.html

run:
	@ cat sample.asl.json | jq -f a.jq

result.txt

{
  "key": "Read messages from SQS Queue",
  "value": {
    "Type": "Task",
    "Resource": "arn:aws:states:::lambda:invoke",
    "OutputPath": "$.Payload",
    "Parameters": {
      "FunctionName": "MapSampleProj-ReadFromSQSQueueLambda-1MY3M63RMJVA9"
    },
    "Next": "Are there messages to process?"
  }
}
{
  "key": "Write message to DynamoDB",
  "value": {
    "Type": "Task",
    "Resource": "arn:aws:states:::dynamodb:putItem",
    "ResultPath": null,
    "Parameters": {
      "TableName": "MapSampleProj-DDBTable-YJDJ1MKIN6C5",
      "ReturnConsumedCapacity": "TOTAL",
      "Item": {
        "MessageId": {
          "S.$": "$.MessageDetails.MessageId"
        },
        "Body": {
          "S.$": "$.MessageDetails.Body"
        }
      }
    },
    "Next": "Remove message from SQS queue"
  }
}
{
  "key": "Remove message from SQS queue",
  "value": {
    "Type": "Task",
    "Resource": "arn:aws:states:::lambda:invoke",
    "InputPath": "$.MessageDetails",
    "ResultPath": null,
    "Parameters": {
      "FunctionName": "MapSampleProj-DeleteFromSQSQueueLambda-198J2839ZO5K2",
      "Payload": {
        "ReceiptHandle.$": "$.ReceiptHandle"
      }
    },
    "Next": "Publish message to SNS topic"
  }
}
{
  "key": "Publish message to SNS topic",
  "value": {
    "Type": "Task",
    "Resource": "arn:aws:states:::sns:publish",
    "InputPath": "$.MessageDetails",
    "Parameters": {
      "Subject": "Message from Step Functions!",
      "Message.$": "$.Body",
      "TopicArn": "arn:aws:sns:us-east-1:012345678910:MapSampleProj-SNSTopic-1CQO4HQ3IR1KN"
    },
    "End": true
  }
}

sample.asl.json

{
  "Comment": "An example of the Amazon States Language for reading messages from an SQS queue and iteratively processing each message.",
  "StartAt": "Read messages from SQS Queue",
  "States": {
    "Read messages from SQS Queue": {
      "Type": "Task",
      "Resource": "arn:aws:states:::lambda:invoke",
      "OutputPath": "$.Payload",
      "Parameters": {
        "FunctionName": "MapSampleProj-ReadFromSQSQueueLambda-1MY3M63RMJVA9"
      },
      "Next": "Are there messages to process?"
    },
    "Are there messages to process?": {
      "Type": "Choice",
      "Choices": [
        {
          "Variable": "$",
          "StringEquals": "No messages",
          "Next": "Finish"
        }
      ],
      "Default": "Process messages"
    },
    "Process messages": {
      "Type": "Map",
      "Next": "Finish",
      "ItemsPath": "$",
      "Parameters": {
        "MessageNumber.$": "$$.Map.Item.Index",
        "MessageDetails.$": "$$.Map.Item.Value"
      },
      "Iterator": {
        "StartAt": "Write message to DynamoDB",
        "States": {
          "Write message to DynamoDB": {
            "Type": "Task",
            "Resource": "arn:aws:states:::dynamodb:putItem",
            "ResultPath": null,
            "Parameters": {
              "TableName": "MapSampleProj-DDBTable-YJDJ1MKIN6C5",
              "ReturnConsumedCapacity": "TOTAL",
              "Item": {
                "MessageId": {
                  "S.$": "$.MessageDetails.MessageId"
                },
                "Body": {
                  "S.$": "$.MessageDetails.Body"
                }
              }
            },
            "Next": "Remove message from SQS queue"
          },
          "Remove message from SQS queue": {
            "Type": "Task",
            "Resource": "arn:aws:states:::lambda:invoke",
            "InputPath": "$.MessageDetails",
            "ResultPath": null,
            "Parameters": {
              "FunctionName": "MapSampleProj-DeleteFromSQSQueueLambda-198J2839ZO5K2",
              "Payload": {
                "ReceiptHandle.$": "$.ReceiptHandle"
              }
            },
            "Next": "Publish message to SNS topic"
          },
          "Publish message to SNS topic": {
            "Type": "Task",
            "Resource": "arn:aws:states:::sns:publish",
            "InputPath": "$.MessageDetails",
            "Parameters": {
              "Subject": "Message from Step Functions!",
              "Message.$": "$.Body",
              "TopicArn": "arn:aws:sns:us-east-1:012345678910:MapSampleProj-SNSTopic-1CQO4HQ3IR1KN"
            },
            "End": true
          }
        }
      }
    },
    "Finish": {
      "Type": "Succeed"
    }
  }
}