Methods to Interact With Sink Attributes about logr

[thockin]

At best, these would be optional interfaces, so you'd have to do something like:

func myFunc(log logr.Logger) {
    if name, ok := log.GetName(); ok {
        if name != "something" {
            log = log.WithName("something")
        }
    }
}

Underneath, it would test the LogSink for support and tell you if it supported it or not.

Deleting a key would be the same, though I am more suspicious of that use-case.

A more DIY approach would be something like:

func MyFunc(log logr.Logger) {
    myFuncInternal(logr.WithName("something").WithValues("key", "value"))
}

func myFuncInternal(log logr.Logger) {
    // do stuff
    // recursion calls myFuncInternal
}

[pohly]

I have duplicates of the key key with different values which makes the field useless.

I'm not so sure about this. My understanding of the "repeated key" semantic is that the last valye wins, so (in JSON) {"foo": "bar", "foo": "x"} would be equivalent to {"foo": "x"}. But later I learned that the JSON spec doesn't actually guarantee that. It's up to the parser which value it uses.

This makes it a problem of the log backend. The klog text backend doesn't de-duplicate logger.WithValues("foo", "var").WithValues("foo", "x"). It does de-duplicate logger.WithValues("foo", "bar").Info("something", "foo", "x"). My rationale was that WithValues is easier to keep under control such that keys are unique, whereas duplication of keys with log calls is currently unavoidable in Kubernetes (contextual logging and thus WithValues is optional). Given what you described it would make more sense to always de-duplicate everything, even if that causes overhead.

zap doesn't de-duplicate. It seems to rely on JSON parsers using the latest value.

[thockin]

Strictly, JSON fields are reorderable. Practically, I think plenty of things depen on in-order processing.

FWIW: funcr does not de-dup keys, either. It could de-dup across successive WithValues calls, but de-duping across WithValues and Info/Error calls is harder and more expensive (WithValues is pre-rendered).