Please don't use custom object serialization for pods. Please either use klog.KObjs(pendingPods) to get basic information like pod name and namespace or propose custom struct that will include fields that should be printed.

cc @pohly
This is interesting case where we want to log slice of K8s object but with additional information, maybe you have suggestion how to best handle it.

It's possible to write a custom formatter like this:

type formatter *v1.Pod

func (f formatter) String() string {
    return fmt.Sprintf("%s/%s ...", f.Namespace, f.Name, ....)
}

func (f formatter) MarshalLog interface{} {
    return struct {
        Namespace, Name string
        <other data>
    } {
       Namespace: f.Namespace,
       Name: f.Name,
       <other data>
   }
}

var _ logr.Marshaler = formatter{}

klog.Infos("some data about a pod", "pod", formatter(pod))

Text output via klog will call Stringer and JSON output will call MarshalLog, then render the struct.

This example is for a single pod. The same works with []*v1.Pod or any other type, it just gets a bit more complex.

So before this new helper lib is available, we keep the current code as-is?

If this PR needs a replacement for podData.WriteString and printPod, then this PR also would be the right place to implement this custom formatter.

It could be local to the pkg/scheduler/internal/cache/debugger package. Or is the same code also needed somewhere else?

If this PR needs a replacement for podData.WriteString and printPod

I don't have a strong option on this as the debugger package is not extensively used, esp. not by the regular end-users.

Or is the same code also needed somewhere else?

I think the pattern is only used in the debugger pkg.

@shivanshu1333: do you intend to implement such a formatter as part of this PR?

Yes, actually I've some doubts I need your help to figure out the right way to do this, I had posted a query in slack for the same https://kubernetes.slack.com/archives/C020CCMUEAX/p1636304943054700

This of course then also needs to be updated in formatter.go.

In #104868 it was pointed out that multi-line strings do not actually get printed as multiple lines, making the text output fairly hard to read.

I wonder whether the same happens here... yes, it does, as your unit test in https://gist.github.com/shivanshu1333/3e7b7cda9fad55c2065900cd30f75781 shows.

I suspect the scheduler developers will consider this as a regression because it makes the text output less useful to them.

Your formatter looks (mostly) good to me and we should come back to it once we know how to emit multi-line strings in text format, but for now we should keep the original klog.Info(d.printNodeInfo(name, nodeInfo)) and
klog.Infof("Dump of scheduling queue:\n%s", podData.String()).

This if check can be removed.

This if check can be removed.