feat(log) add logging system

backend/src/logger.rs

@@ -0,0 +1,72 @@
+use std::{env, io};
+
+use chrono::Local;
+use tracing::{error, info, Level};
+use tracing_appender::{non_blocking, rolling};
+use tracing_appender::non_blocking::WorkerGuard;
+use tracing_subscriber::{fmt, Registry};
+use tracing_subscriber::fmt::format::Writer;
+use tracing_subscriber::fmt::MakeWriter;
+use tracing_subscriber::fmt::time::FormatTime;
+use tracing_subscriber::fmt::writer::MakeWriterExt;
+use tracing_subscriber::layer::SubscriberExt;
+
+use crate::constants::GLOBAL_TIME_FORMAT;
+
+struct LocalTimer;
+
+impl FormatTime for LocalTimer {
+    fn format_time(&self, w: &mut Writer<'_>) -> std::fmt::Result {
+        write!(w, "{}", Local::now().format(GLOBAL_TIME_FORMAT))
+    }
+}
+
+type LogWriter = dyn for<'writer> MakeWriter<'writer, Writer = dyn io::Write + 'static> + 'static;
+
+pub fn init() -> (WorkerGuard, WorkerGuard) {
+    let log_path = env::var("LOG_ROOT_DIR").unwrap_or_else(|e| {
+        panic!("[Fatal] failed to load LOG_ROOT_DIR: {}", e);
+    });
+
+    let log_path = format!("{}/backend", log_path);
+
+    let (info_log_writer, info_guard) = non_blocking(rolling::never(&log_path, "info.log"));
+    // let info_log = info_log.with_max_level(Level::TRACE);
+
+    let (err_log_writer, error_guard) = non_blocking(rolling::never(&log_path, "error.log"));
+    // let error_log = error_logging_handle.with_filter(|log| log.level().eq(&Level::ERROR));
+
+    let log_format = tracing_subscriber::fmt::format()
+        .with_level(true)
+        .with_target(true)
+        .with_source_location(true)
+        .with_timer(LocalTimer);
+
+    // todo: separate errors/warnings/info logs
+    let subscribers = Registry::default()
+        .with(
+            fmt::Layer::default()
+                .with_writer(info_log_writer)
+                // .with_max_level(Level::TRACE)
+                .with_ansi(false),
+        )
+        .with(
+            fmt::Layer::default()
+                .with_writer(err_log_writer)
+                .with_ansi(false),
+        )
+        .with(
+            fmt::Layer::default()
+                .with_writer(io::stdout)
+                .with_ansi(true)
+                .event_format(log_format),
+        );
+
+    tracing::subscriber::set_global_default(subscribers)
+        .expect("[Fatal] Failed to setup logging system");
+
+    info!("Module Started: Logger");
+
+    // error!("test");
+    (info_guard, error_guard)
+}