replacing logrus with slog v1

[JodhwaniMadhur]

What is the problem I am trying to address?

Removing logrus and implementing slog

How is the fix applied?

Replaced logrus.

Implemented functions that are missing in slog but were present in slog

What GitHub issue(s) does this PR fix or close?

Fixes #1890

[Ullaakut]

Superficial review

[marwan-at-work]

@JodhwaniMadhur the idea here is correct: we should replace logrus with log/slog. However, the approach should be as follows:

1. Let's only change the athens/log package. So that importers of the athens/log package don't need to change at all. We simply implement a slog version of the Entry interface.
2. This will fix some of your build errors above, and it will also divide up the PR and make it a smaller change rather than a large one.
3. If we ever felt that we needed to change athens/log we can do so in a separate/follow up discussion.

[Ullaakut]

I assume this doesn't compile/doesn't work as intended at the moment does it?

[JodhwaniMadhur]

I assume this doesn't compile/doesn't work as intended at the moment does it?

Nope, it doesn't. But will take care of everything.

thanks for all the suggestions.

[JodhwaniMadhur]

@JodhwaniMadhur the idea here is correct: we should replace logrus with log/slog. However, the approach should be as follows:

1. Let's only change the athens/log package. So that importers of the athens/log package don't need to change at all. We simply implement a slog version of the Entry interface.
2. This will fix some of your build errors above, and it will also divide up the PR and make it a smaller change rather than a large one.
3. If we ever felt that we needed to change athens/log we can do so in a separate/follow up discussion.

But then in the entry we have Severity coming in as logrus.Level which indeed should be then a generic levels decided by us or we switch to slog.Level, isn't it? and severity is outside of entry

[JodhwaniMadhur]

can anyone guide me as to how I should modify the Severity function? as it was designed for logrus but for slog the TestSeverity fails

for logrus, the levels are
Panic = 0
Fatal = 1
err = 2
warn = 3
Info = 4
Debug = 5
Trace = 6

but for slog the levels are:
err = 8
warn = 4
info = 0
debug = -4

@marwan-at-work @nrwiersma @Ullaakut

[marwan-at-work]

As to your question, if you look at the entry interface, we weren't using all of logrus's levels, we also were just using debug/info/warn/error, so let's just keep those.

[marwan-at-work]

We should keep this interface exactly the same and just implement it in terms of slog, why create all of the new methods above if they were not being used?

[JodhwaniMadhur]

Even if I remove the rest, I will have to keep them in a separate interface and take those interfaces in entry since if I write all functions inside entry, the linter in the pipeline gives error for interfacebloat

[JodhwaniMadhur]

As for the extra methods, I can remove those but the problem for logrus vs slog levels and problems in Severity due to this still remains

[marwan-at-work]

As for the extra methods, I can remove those but the problem for logrus vs slog levels and problems in Severity due to this still remains

I'm not sure how they still remain, all you need to do is create a separate file that implements Entry in terms of log/slog?

[marwan-at-work]

Here's an example:

type slogger struct {
	l *slog.Logger
}

// Debugf implements Entry.
func (s *slogger) Debugf(format string, args ...any) {
	s.l.Debug(fmt.Sprintf(format, args...))
}

// Errorf implements Entry.
func (s *slogger) Errorf(format string, args ...any) {
	s.l.Error(fmt.Sprintf(format, args...))
}

For severity in the errors package, you can continue to use logrus levels, or you can change it to slog, or better yet create an abstraction in the athens log package because the error package shouldn't import a third party lib

[matt0x6F]

An abstraction is preferred, imo.

[JodhwaniMadhur]

ok, got the abstraction part but still a bit confused, so you mean to say that i should only have the function declarations in entry and then implement those in log.go like it was done before my changes for SystemErr implementation or like for WithFields implementation?

[JodhwaniMadhur]

??

[marwan-at-work]

I mean that you keep the interface exactly the same and just create a log/slog v1 implementation of that interface (in a separate file, within the same package). Therefore, nothing changes outside of the log package (and the errors/severity, due to the abstraction we talked about above)

[matt0x6F]

I would expect to see a go.mod/go.sum change that shows we removed Logrus as a dependency