funcr Feature Request: Add LogInfoLevel Option to skip logging level in the info log

[spacewander]

Currently, the info level is always logged:

logr/funcr/funcr.go

Line 743 in 41d36ee

args = append(args, "level", level, "msg", msg)

.

However, in some situations, people may not use the log level or have an alternative to the integer log level field. So logging the integer log level in these situations may be a little useless.

The zapr implementation has an option called LogInfoLevel to control if the numeric log level is logged:
https://github.com/go-logr/zapr/blob/78b8af5329abd1ba8695aad821f95fb2e7f4e651/zapr.go#L270

What about adding a similar feature to logr? I am glad to implement it if it is accepted.

[pohly]

Do you see an advantage in using funcr compared to some other backend (like zapr, which you already mentioned)? I'm not sure how much further changes will be done (or accepted) there.

Note that as of 1.3.0, you can also use slog backends, so if you are on Go 1.21 and worried about additional dependencies, then you can configure the log/slog JSON handler as backend for logr.

[thockin]

I don't think one is too bad for funcr, and I would probably accept it as a PR. Something @pohly said without saying - funcr doesn't currently support slog, whereas slog.JSONHandler can be used as a logr backend. I would also be OK to make funcr support slog better, but I have not looked at doing that.

[spacewander]

Do you see an advantage in using funcr compared to some other backend (like zapr, which you already mentioned)? I'm not sure how much further changes will be done (or accepted) there.

Note that as of 1.3.0, you can also use slog backends, so if you are on Go 1.21 and worried about additional dependencies, then you can configure the log/slog JSON handler as backend for logr.

In fact, I only use the Formatter from func. I am building a framework upon the Go extension of Envoy. The formatted string will be written to Envoy's log by calling Envoy's log API.

If I use zapr or slog, there will be two headers for each log: one from Envoy, the other from Go logger. Therefore I choose to build a logger from scratch.

[spacewander]

I don't think one is too bad for funcr, and I would probably accept it as a PR. Something @pohly said without saying - funcr doesn't currently support slog, whereas slog.JSONHandler can be used as a logr backend. I would also be OK to make funcr support slog better, but I have not looked at doing that.

Great! I will give it a try when I have free time.

[pohly]

In fact, I only use the Formatter from func.

There are similar building blocks for slog - see https://github.com/golang/go/wiki/Resources-for-slog. But enhancing funcr might be simpler.

[spacewander]

In fact, I only use the Formatter from func.

There are similar building blocks for slog - see https://github.com/golang/go/wiki/Resources-for-slog. But enhancing funcr might be simpler.

@pohly
Thanks for pointing out that! I am using Go 1.20 so slog is not available for now, but I will investigate it once we upgrade the Go version.