Client-go: support modifying an object in jsonpath package

[mengqiy]

var nodes = jp.apply(data, '$..author', function(value) { return value.toUpperCase() });
// [
// { path: ['$', 'store', 'book', 0, 'author'], value: 'NIGEL REES' },
// { path: ['$', 'store', 'book', 1, 'author'], value: 'EVELYN WAUGH' },
// { path: ['$', 'store', 'book', 2, 'author'], value: 'HERMAN MELVILLE' },
// { path: ['$', 'store', 'book', 3, 'author'], value: 'J. R. R. TOLKIEN' }
// ]

Have something similar to https://github.com/dchester/jsonpath#jpapplyobj-pathexpression-fn in our jsonpath package

/kind feature

[mengqiy]

/help-wanted

[nikhita]

/help

[huydinhle]

I saw you guys need help from a contributor. I would like to help. Although I don't really understand what's exactly the problem is

[nikhita]

@mengqiy can you elaborate ^^?

[mengqiy]

I'd imagine it have something like:

Given a jsonpath string and modifier function func(interface{}) interface{}.
Our jsonpath lib should provide the ability to apply the modifier function to the node(s) specified by the jsonpath.
For example, given the following json object

{
  "store": {
    "book": [ 
      {
        "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95
      }, {
        "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}

And having the modifier function and jsonpath

jsonpath := "$.store.book[1].author"

fn := func(in interface{}) interface{} {
  s := in.(string)
  return strings.ToUpper(s)
}



md5-83224704915a9e50e148af92ae315e8d



{
  "store": {
    "book": [ 
      {
        "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95
      }, {
        "category": "fiction",
        "author": "EVELYN WAUGH",
        "title": "Sword of Honour",
        "price": 12.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}

[sttts]

IMO this does not belong into client-go. We are not a json library. If we want more, either we use another library or we split out the jsonpath package from client-go in its own project.

[sttts]

Also compare https://github.com/kubernetes/kubernetes/blob/1db0024ec99cb2e4a2154df22008c27b344190e0/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/jsonpath_test.go, yet another internal jsonpath library. All that should go into k8s.io/jsonpath or similar.

[nikhita]

All that should go into k8s.io/jsonpath or similar.

Is this still a "help wanted" issue? Removing help-wanted for now.

/remove-help

[mengqiy]

Maybe not.
Creating a new repo in the org is non-trivial. This issue may be not easy for new contributors.

[fejta-bot]

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[k8s-ci-robot]

@fejta-bot: Closing this issue.

In response to this:

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