Get outputs from jq specific line

Question

The command:

create_subnet=$(aws ec2 create-subnet --vpc-id "$create_vpc" --cidr-block 10.0.1.0/24 | jq -r '.subnet[].subnetid')

The output:

"subnet": {

    "availabilityzone": "us-west-1b",
    "availabilityzoneid": "usw1-az3",
    "availableipaddresscount": 251,
    "cidrblock": "10.0.1.0/24",
    "defaultforaz": false,
    "mappubliciponlaunch": false,
    "state": "available",
    "subnetid": "subnet-0745e1611cf09a69a",
    "vpcid": "vpc-07c1508663040cbf7",
    "ownerid": "232856593288",
    "assignipv6addressoncreation": false,
    "ipv6cidrblockassociationset": [],
    "subnetarn": "arn:aws:ec2:us-west-1:232856593288:subnet/subnet-0745e1611cf09a69a",
    "enabledns64": false,
    "ipv6native": false,
    "privatednsnameoptionsonlaunch": {
      "hostnametype": "ip-name",
      "enableresourcenamednsarecord": false,
      "enableresourcenamednsaaaarecord": false
    }
  }
}

I need to take the line which is: subnet-0745e1611cf09a69a and store it into the variable create_subnet

When i execute the script with bash -x i get the follow error:

++ jq -r '.subnet[].subnetid'
++ aws ec2 create-subnet --vpc-id vpc-09399bbc31c98efe7 --cidr-block 10.0.1.0/24
jq: error (at <stdin>:24): Cannot iterate over null (null)

Maybe i writed the syntax wrong or something like that? I mean for this - jq -r '.subnet[].subnetid'

Answer 1

.subnet is not an array, so the [] is not necessary.

jq -r '.subnet.subnetid'

This works for me.