Log format .json for Rust Crate: 'env_logger'

[cameronelliott]

I am new to lnav, but it looks pretty slick!

I'd like it use it with Rust, and it seems env_logger is one of the most popular formatters for the Rust log crate and logging ecosystem.

It's default logs look like:

[2017-11-09T02:12:24Z DEBUG my_app] this is a debug message
[2017-11-09T02:12:24Z ERROR my_app] this is printed by default
[2017-11-09T02:12:24Z INFO my_app] the answer was: 12

I did some investigating to see if there was maybe a pre-existing format to use. Syslog could work, but it seems less than ideal to me, honestly.

Anyway I'd like to hear if there is a good or recommended setup for Rust that I somehow overlooked.

Thanks

[tstack]

It looks like there's not a builtin log format that recognizes these types of messages. I don't have any time right this second, but can work on it tonight/tomorrow. If you want to give it a go, try the regex101 integration for creating a log format. That's what I will be doing.

[cameronelliott]

Thanks for the reply. Interestingly, none of the flavors at regex101.com seem to work without errors on what I pulled from block_log.json
What flavor should I be using? Maybe I am missing another flag/param.

[cameronelliott]

Making some progress with crate simple_logger rather than env_logger.
ChatGPT provided a nice starting point by asking for PCRE2 flavor. (I hope lnav uses PCRE2! lol)

[cameronelliott]

Okay, let me give env_logger a stab

[tstack]

Yes, lnav uses PCRE2

[cameronelliott]

Okay, thanks for the help to get started. And of course, thanks for sharing lnav with the world.

Here are my REs
rust_env_logger: https://regex101.com/r/Ri1Klm
rust_simple_logger: https://regex101.com/r/oPk7GF/2

I think mentioning PCRE2 in the (awesome) docs would be a nice small tweak.

Thanks for pointing out the section on Regex101, I just hadn't read that far in the docs, so your pointing it out closed the loop for me.

[tstack]

I've pushed a change to the top of tree with both formats:

https://github.com/tstack/lnav/blob/master/src/formats/env_logger_log.json
https://github.com/tstack/lnav/blob/master/src/formats/simple_rs_log.json

You can download those files and install them with:

$ lnav -i env_logger_log.json
$ lnav -i simple_rs_log.json

[cameronelliott]

That's awesome! I guess you didn't like the names with rust_ at the front? No matter, it's awesome they are in the program now.