ref(backend) start of refactor

backend/api_server/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "api_server"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+constants = { path = "../constants" }
+chrono = "0.4.38"
+tracing = "0.1.40"
+tracing-subscriber = "0.3.18"
+tracing-appender = "0.2.3"
+dotenv = "0.15.0"

backend/api_server/src/init.rs

@@ -0,0 +1,22 @@
+use crate::logger;
+use std::env;
+use tracing_appender::non_blocking::WorkerGuard;
+
+pub fn logger_init() -> (WorkerGuard, WorkerGuard) {
+    logger::init()
+}
+
+pub fn load_env() {
+    if let Some(env_file) = env::args().nth(1) {
+        match dotenv::from_filename(&env_file) {
+            Ok(_) => {
+                println!("[info] env loaded from {}, starting up", env_file);
+            }
+            Err(e) => {
+                panic!("[fatal] failed to read {}: {}", env_file, e);
+            }
+        }
+    } else {
+        println!("[info] no .env file referred, starting up")
+    }
+}

backend/api_server/src/logger.rs

@@ -0,0 +1,68 @@
+use std::{env, io};
+
+use chrono::Local;
+use tracing::info;
+use tracing_appender::non_blocking::WorkerGuard;
+use tracing_appender::{non_blocking, rolling};
+use tracing_subscriber::fmt::format::Writer;
+use tracing_subscriber::fmt::time::FormatTime;
+use tracing_subscriber::fmt::MakeWriter;
+use tracing_subscriber::layer::SubscriberExt;
+use tracing_subscriber::{fmt, Registry};
+
+struct LocalTimer;
+
+impl FormatTime for LocalTimer {
+    fn format_time(&self, w: &mut Writer<'_>) -> std::fmt::Result {
+        write!(
+            w,
+            "{}",
+            Local::now().format(constants::time::DEFAULT_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 (err_log_writer, error_guard) = non_blocking(rolling::never(&log_path, "error.log"));
+
+    let log_format = tracing_subscriber::fmt::format()
+        .with_level(true)
+        .with_target(true)
+        .with_source_location(true)
+        .with_timer(LocalTimer);
+
+    let subscribers = Registry::default()
+        .with(
+            fmt::Layer::default()
+                .with_writer(info_log_writer)
+                .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");
+
+    (info_guard, error_guard)
+}

backend/api_server/src/main.rs

@@ -0,0 +1,7 @@
+mod init;
+mod logger;
+
+fn main() {
+    init::load_env();
+    let _guards = init::logger_init();
+}