using jq I want to output json object within a json object including the keys not just the value

I have this stored as a file:

{
  "Targets": [
    {
      "Id": "xxx_hourly_cron",
      "Arn": "arn:aws:ecs:eu-west-2:000000000000:cluster/drupal-cluster",
      "RoleArn": "arn:aws:iam::000000000000:role/ecsEventsRole",
      "EcsParameters": {
        "TaskDefinitionArn": "arn:aws:ecs:eu-west-2:000000000000:task-definition/xxx-cron:55",
        "TaskCount": 1,
        "EnableECSManagedTags": false,
        "EnableExecuteCommand": false,
        "PropagateTags": "TASK_DEFINITION"
      }
    }
  ]
}

Using bash and jq I want to trim it down this this:

{
  "TaskDefinitionArn": "arn:aws:ecs:eu-west-2:000000000000:task-definition/xxx-cron:55",
  "TaskCount": 1,
  "EnableECSManagedTags": false,
  "EnableExecuteCommand": false,
  "PropagateTags": "TASK_DEFINITION"
}

I have tried this but it does not output the keys:

cat rule-target.json | jq '(.Targets[] .EcsParameters[])'

Solution 1:

You are so close:

$ jq '.Targets[].EcsParameters' rule-target.json 
{
  "TaskDefinitionArn": "arn:aws:ecs:eu-west-2:000000000000:task-definition/xxx-cron:55",
  "TaskCount": 1,
  "EnableECSManagedTags": false,
  "EnableExecuteCommand": false,
  "PropagateTags": "TASK_DEFINITION"
}

As EcsParameters isn't an array, you shouldn't unwrap it ([]).

Usually it's a useless use of cat when doing cat file | cmd, many commands takes files as arguments:

cmd -flag -flag2 file1.txt file2.txt

and if they don't then you can redirect stdin:

cmd -flag -flag2 < file1.txt

Solution 2:

I think you want:

jq '(.Targets[]|.EcsParameters)' rule-target.json

Which results in:

{
  "TaskDefinitionArn": "arn:aws:ecs:eu-west-2:000000000000:task-definition/xxx-cron:55",
  "TaskCount": 1,
  "EnableECSManagedTags": false,
  "EnableExecuteCommand": false,
  "PropagateTags": "TASK_DEFINITION"
}