| 1 | //! stderr logging. Under systemd (`JOURNAL_STREAM` set) timestamps and colors |
| 2 | //! are dropped because journald adds its own. `RUST_LOG` overrides |
| 3 | //! `log.level`; otherwise the level follows the config across reloads. |
| 4 | |
| 5 | use std::io::IsTerminal; |
| 6 | use std::sync::OnceLock; |
| 7 | |
| 8 | use tracing_subscriber::prelude::*; |
| 9 | use tracing_subscriber::{EnvFilter, Registry, reload}; |
| 10 | |
| 11 | use crate::config::Config; |
| 12 | |
| 13 | static HANDLE: OnceLock<reload::Handle<EnvFilter, Registry>> = OnceLock::new(); |
| 14 | |
| 15 | pub fn init(config: &Config) { |
| 16 | let (filter, handle) = reload::Layer::new(filter_for(config)); |
| 17 | let fmt = tracing_subscriber::fmt::layer() |
| 18 | .with_writer(std::io::stderr) |
| 19 | .with_target(false); |
| 20 | let registry = tracing_subscriber::registry().with(filter); |
| 21 | if std::env::var_os("JOURNAL_STREAM").is_some() { |
| 22 | registry.with(fmt.without_time().with_ansi(false)).init(); |
| 23 | } else { |
| 24 | registry |
| 25 | .with(fmt.with_ansi(std::io::stderr().is_terminal())) |
| 26 | .init(); |
| 27 | } |
| 28 | let _ = HANDLE.set(handle); |
| 29 | } |
| 30 | |
| 31 | /// Apply `log.level` from a freshly loaded config. |
| 32 | pub fn apply(config: &Config) { |
| 33 | if rust_log().is_some() { |
| 34 | return; |
| 35 | } |
| 36 | if let Some(handle) = HANDLE.get() { |
| 37 | let _ = handle.reload(filter_for(config)); |
| 38 | } |
| 39 | } |
| 40 | |
| 41 | fn rust_log() -> Option<String> { |
| 42 | std::env::var("RUST_LOG") |
| 43 | .ok() |
| 44 | .filter(|v| !v.trim().is_empty()) |
| 45 | } |
| 46 | |
| 47 | fn filter_for(config: &Config) -> EnvFilter { |
| 48 | if let Some(spec) = rust_log() { |
| 49 | match EnvFilter::try_new(&spec) { |
| 50 | Ok(filter) => return filter, |
| 51 | Err(e) => eprintln!("ignoring invalid RUST_LOG {spec:?}: {e}"), |
| 52 | } |
| 53 | } |
| 54 | // Validated at config load time. |
| 55 | EnvFilter::try_new(&config.log.level).unwrap_or_else(|_| EnvFilter::new("info")) |
| 56 | } |