Add support for Key-Value pairs

[ellttBen]

Hi there,
As discussed in #329, this PR implements support for the log::kv structured logging API.
These are some user-facing choices I have made:

• Everything is implemented behind a log_kv feature
• Support is added in the two encoders json and pattern:
  • The json message has an attributes field which is a serialized map of the record's structured logs
  • The pattern encoder has a new K or key_value formatter which functions exactly like the mdc formatter.

If this sounds okay, I can also edit the documentation.

[gauntl3t12]

Looks great! Lets try and get some more tests in there and the documentation

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

Attention: Patch coverage is 88.63636% with 5 lines in your changes missing coverage. Please review.

Project coverage is 62.35%. Comparing base (8ab1b34) to head (8081d03).
Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
src/encode/pattern/mod.rs	84.84%	5 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #362      +/-   ##
==========================================
- Coverage   63.39%   62.35%   -1.05%     
==========================================
  Files          24       25       +1     
  Lines        1557     1591      +34     
==========================================
+ Hits          987      992       +5     
- Misses        570      599      +29     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[ellttBen]

Hi, sorry for the delay, I'm still keen to get this merged. I have rebased this PR and squashed the commits. If more documentation is needed I can get that in ASAP as well.

[gauntl3t12]

I'll take a look at this soon. I'll do my best to get a hold of the project owner and work through our recent batches of PRs

[sdroege]

What's the status of this PR?

[gauntl3t12]

@sdroege I am targeting next week to start working with the owner of the repo. Appreciate everyone's hard work on the recent batch of MRs and can't wait to get things moving again!

[sdroege]

That sounds great, thanks!

[estk]

I left a couple of comments, but looking really good.

One more general question, did you attempt to wrap log::kv::Source in a newtype and impl serde::Serialize on it?

Just wondering because I was thinking about the tradeoffs of allocating a whole BTree vs the annoyance of adding lifetimes to Message.

[ellttBen]

Thanks for the review @estk, I have followed your suggestion and investigated directly playing around with Serde traits.
I implemented the suggested review changes, and also changed the approach for json encoding to directly (via a new wrapper type) serializing from the &log::kv::Source dynamic reference. The error handling is a bit finicky with transformations between log::kv::Error and the serializer errors (log::kv::Error::boxed requires Send+Sync, and the serde traits make no such guarantees about allowable errors), but I think overall it makes more sense.

[estk]

nailed it

[estk]

blocked on #367

[SL-RU]

Hi! What is the current status of the MR?

[gauntl3t12]

Hi! What is the current status of the MR?

@SL-RU we're still waiting on the blocked PR

[SL-RU]

Hi! What is the current status of the MR?

[gauntl3t12]

Hey! Sorry but all PRs are blocked by the PR fixing the deprecated API. I've been too busy of late to bug @estk and get it moving again. Please feel free to take a look at that PR and suggest options you might see in helping bring it to closure.

[SL-RU]

Hi, what is current status? What blocks this PR now?

[SL-RU]

It seems repo was abandoned. Isn't it?
Almost half of year without progress?

[gauntl3t12]

@SL-RU yes, as far as I'm concerned this project is abandoned. The owner, was not happy with the solution to resolve #367 which blocks all further PRs. Until such a time as he turns the project over to be community driven, I don't foresee a solution to grow the project.

[SL-RU]

@SL-RU yes, as far as I'm concerned this project is abandoned. The owner, was not happy with the solution to resolve #367 which blocks all further PRs. Until such a time as he turns the project over to be community driven, I don't foresee a solution to grow the project.

Thank you for the reply, do you know some project with same functionality?

[gauntl3t12]

Unfortunately no I do not. I know the author moved to trace4rs with his employer. However, that project also appears to have died.

[estk]

Bryan had agreed to send me an email when he saw PRs as ready. My last email from him was Feb last year.

i am adding this review to my queue.

[estk]

@ellttBen can you please rebase?