[Document] more log verbosity control

[shizunge]

I only found 'LLDAP_VERBOSE' or verbose in the config file to change the log verbosity. It seem can take only true or false.

Could we add a 'loglevel' config switch for better control please? which can take e.g. debug info warning error. I want to suppress the info level log, which is default on.

It may already be there. But I did not find it in any documents.

Thanks

[nitnelave]

It's not documented, but you can use the RUST_LOG env variable. If you set it to warn it should get rid of the info logs. See https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html for more info, you can do some more advanced filtering.