pimalaya_cli/log.rs
1//! Logger initialization from the shared log flags.
2
3use std::fs::OpenOptions;
4
5use anyhow::Result;
6use env_logger::{Builder, Target};
7use log::LevelFilter;
8
9use crate::clap::args::LogFlags;
10
11/// Initializes the process logger from the shared log flags.
12pub struct Logger;
13
14impl Logger {
15 /// Initialises `env_logger` from `log`. When [`LogFlags::file`]
16 /// is set the log target is opened in append mode (creating it
17 /// if missing) and used for output; otherwise logs go to stderr
18 /// as usual.
19 ///
20 /// Opening the log file is fallible: if the caller asked for one
21 /// but we cannot create or open it, the error is returned rather
22 /// than silently falling back to stderr and polluting interactive
23 /// prompts.
24 pub fn try_init(log: &LogFlags) -> Result<()> {
25 let mut builder = Builder::new();
26
27 match log.level {
28 Some(level) => {
29 builder.filter_level(level.into());
30 }
31 None => {
32 builder.filter_level(LevelFilter::Off);
33 builder.parse_default_env();
34 }
35 }
36
37 if let Some(path) = &log.file {
38 let file = OpenOptions::new().create(true).append(true).open(path)?;
39 builder.target(Target::Pipe(Box::new(file)));
40 }
41
42 builder.try_init()?;
43 Ok(())
44 }
45}