使用jq添加并修改JSON对象：基于指定示例完成转换

Hey there! Let's walk through how to use jq to tweak your JSON into the exact structure you need. Here's everything you need to know:

Sample Input & Expected Output #

First, let's recap what we're starting with and where we want to end up.

Sample JSON Input #

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AllowFullAccess",
      "Effect": "Allow",
      "Principal": {
        "AWS": [
          "arn:aws:iam::XXXX:user/test",
          "arn:aws:iam::XXXX:root"
        ]
      },
      "Action": "s3:*",
      "Resource": [
        "arn:aws:s3:::test-dev-cognito-settings-us-west-2/*"
      ],
      "Condition": {
        "StringNotLike": {
          "aws:userId": [
            "AZASDASDSADA"
          ]
        }
      }
    }
  ]
}

Expected JSON Output #

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AllowFullAccess",
      "Effect": "Allow",
      "Principal": {
        "AWS": [
          "arn:aw..."
        ]
      }
    }
  ]
}

The jq Command #

This one-liner will do all the heavy lifting:

jq '.Statement[0] |= {Sid, Effect, Principal: {AWS: ["arn:aw..."]}}' input.json

Let's Break It Down #

• .Statement[0]: Targets the first (and only) object inside the Statement array
• |=: Tells jq "take the thing I just selected, and modify it with the following logic"
• {Sid, Effect, Principal: {AWS: ["arn:aw..."]}}: Reconstructs the object to only keep the Sid and Effect fields as-is, and replaces the Principal with your desired truncated AWS ARN array.

Handling Multiple Statement Entries #

If you ever have more than one object in the Statement array and want to apply this change to all of them, just swap out the [0] for [] to iterate over every entry:

jq '.Statement[] |= {Sid, Effect, Principal: {AWS: ["arn:aw..."]}}' input.json

Testing It Out #

Run the command against your input JSON file, and you'll get exactly the output you're looking for. Easy peasy!

内容的提问来源于stack exchange，提问作者Jayesh Dhandha