Question 109956 in Json Question posted in
Our archive of expertly curated questions and answers provides insights and solutions to common problems related to this popular data interchange format. From parsing and manipulating JSON data to integrating it with various programming languages and web services, our archive has got you covered. Start exploring today and take your JSON skills to the next level

Extract an array of key-value pairs using JQ and from pre-filtered JSON

I want to extract an array of key-value pairs from the below JSON, that is generated by the following AWS CLI script. The array should contain the load balancer names.

aws elbv2 describe-load-balancers | jq '.LoadBalancers[] | select(.LoadBalancerName | startswith("MY_LOAD_BALANCER_NAME"))'

I tried adding a JQ filter to the end of this script, as follows, but it did not work:

aws elbv2 describe-load-balancers | jq '.LoadBalancers[] | select(.LoadBalancerName | startswith("MY_LOAD_BALANCER_NAME"))' | jq -r .LoadBalancers[].LoadBalancerName

Here’s a shorten version of my JSON output:

{
    "LoadBalancers": [
        {
            "LoadBalancerArn": "arn:aws:elasticloadbalancing...",
            "CreatedTime": "2023-01-26T22:26:42.313000+00:00",
            "LoadBalancerName": "elb_name_123"
        },
        {
            "LoadBalancerArn": "arn:aws:elasticloadbalancing...",
            "CreatedTime": "2023-01-26T22:26:42.313000+00:00",
            "LoadBalancerName": "elb_name_456"
        },
        {
            "LoadBalancerArn": "arn:aws:elasticloadbalancing...",
            "CreatedTime": "2023-01-26T22:26:42.313000+00:00",
            "LoadBalancerName": "elb_name_789"
        }
    ]
}
Tags:

2

Answers


  1. 0

    I don’t know if this is the output format you want. How about this?

    cat output.json | jq '[.LoadBalancers[] | select(.LoadBalancerName | startswith("elb_name")) | { LoadBalancerName: .LoadBalancerName } ]'
[
  {
    "LoadBalancerName": "elb_name_123"
  },
  {
    "LoadBalancerName": "elb_name_456"
  },
  {
    "LoadBalancerName": "elb_name_789"
  }
]

    $ cat output.json 
{
  "LoadBalancers": [
    {
      "LoadBalancerArn": "arn:aws:elasticloadbalancing...",
      "CreatedTime": "2023-01-26T22:26:42.313000+00:00",
      "LoadBalancerName": "elb_name_123"
    },
    {
      "LoadBalancerArn": "arn:aws:elasticloadbalancing...",
      "CreatedTime": "2023-01-26T22:26:42.313000+00:00",
      "LoadBalancerName": "elb_name_456"
    },
    {
      "LoadBalancerArn": "arn:aws:elasticloadbalancing...",
      "CreatedTime": "2023-01-26T22:26:42.313000+00:00",
      "LoadBalancerName": "elb_name_789"
    }
  ]
}
    Login or Signup to reply.
  2. 0

    You don’t need to use an extra jq for filtering AWS cli supports jmespath already.

    You can filter loadbalancers with starts_with

    aws elbv2 describe-load-balancers --query 'LoadBalancers[?starts_with(LoadBalancerName, `elb_name`)].LoadBalancerName'
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search