strapi-elb/jq.md

JQ

Piping into jq

You can cat or bat a file and pipe it into jq.

You can also take a command that returns json and pipe it into jq.

Returning data without "

To return data without jq wrapping results in " use the -r flag.

jq -r

Filtering

Get values from a key

Running aws --profile admin cloudformation describe-stack-resources --stack-name strapi-vpc | jq returns:

{
  "StackResources": [
    {
      "StackName": "strapi-vpc",
      "StackId": "arn:aws:cloudformation:eu-west-1:745437999005:stack/strapi-vpc/a9e41430-8afc-11ea-bdaa-0a736ea8438a",
      "LogicalResourceId": "InternetGateway",
      "PhysicalResourceId": "igw-0e059db8e0795ac32",
      "ResourceType": "AWS::EC2::InternetGateway",
      "Timestamp": "2020-04-30T16:07:42.434Z",
      "ResourceStatus": "CREATE_COMPLETE",
      "DriftInformation": {
        "StackResourceDriftStatus": "NOT_CHECKED"
      }
    },
    {
      "StackName": "strapi-vpc",
      "StackId": "arn:aws:cloudformation:eu-west-1:745437999005:stack/strapi-vpc/a9e41430-8afc-11ea-bdaa-0a736ea8438a",
      "LogicalResourceId": "InternetGatewayAttachment",
      "PhysicalResourceId": "strap-Inter-1413K0IDR1L3N",
      "ResourceType": "AWS::EC2::VPCGatewayAttachment",
      "Timestamp": "2020-04-30T16:08:00.147Z",
      "ResourceStatus": "CREATE_COMPLETE",
      "DriftInformation": {
        "StackResourceDriftStatus": "NOT_CHECKED"
      }
    },

We can then use jq's filtering to return values.

We have a key of StackResources which contains a list: .StackResources[]

We can then pass in the key we want .StackResources[].PhysicalResourceId

aws --profile admin cloudformation describe-stack-resources --stack-name strapi-vpc | jq -r '.StackResources[].PhysicalResourceId' which gives:

"igw-0e059db8e0795ac32"
"strap-Inter-1413K0IDR1L3N"
"strap-Publi-1TS82BV8W4UFD"
"rtb-0cf8d05f71a30ef03"
"subnet-051fe56dc37d8396d"
"rtbassoc-0f7ae2fbdfe6bf2a5"
"subnet-0ea9f2f165a57be27"
"rtbassoc-00a67937c3778e273"
"subnet-09b28d722f41b2dde"
"rtbassoc-0a0a6bd0f8ff641df"
"vpc-029d232726cbf591d"

aws --profile admin cloudformation describe-stack-resources --stack-name strapi-vpc | jq -r '.StackResources[] | .ResourceType + ": " + .PhysicalResourceId'