✨ Adds logging to file

src/main.rs

@@ -20,6 +20,9 @@ use std::str::FromStr;
 
 #[macro_use]
 extern crate rocket;
+extern crate fern;
+#[macro_use]
+extern crate log;
 
 #[get("/")]
 async fn index(state: &State<AppState>) -> Result<NamedFile, Status> {
@@ -28,11 +31,11 @@ async fn index(state: &State<AppState>) -> Result<NamedFile, Status> {
         .map_err(|_| Status::InternalServerError)
 }
 
-fn setup_logging() -> Result<(), fern::InitError> {
+fn setup_logging(log_file: Option<String>) -> Result<(), fern::InitError> {
     let level_raw = env::var("LOG_LEVEL").unwrap_or("INFO".to_string());
     let level = log::LevelFilter::from_str(&level_raw).expect("LOG_LEVEL invalid");
 
-    fern::Dispatch::new()
+    let log = fern::Dispatch::new()
         .format(|out, message, record| {
             out.finish(format_args!(
                 "{} {} [{}] {}",
@@ -43,8 +46,13 @@ fn setup_logging() -> Result<(), fern::InitError> {
             ))
         })
         .level(level)
-        .chain(std::io::stdout())
-        .apply()?;
+        .chain(std::io::stdout());
+
+    if let Some(log_file) = log_file {
+        log.chain(fern::log_file(log_file)?).apply()?;
+    } else {
+        log.apply()?;
+    }
 
     Ok(())
 }
@@ -52,7 +60,9 @@ fn setup_logging() -> Result<(), fern::InitError> {
 #[launch]
 fn rocket() -> _ {
     dotenv::dotenv().ok();
-    setup_logging().expect("Failed to setup logging");
+
+    let log_file = env::var("LOG_FILE");
+    setup_logging(log_file.ok()).expect("Failed to setup logging");
 
     let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
     let static_dir = env::var("STATIC_DIR").expect("STATIC_DIR must be set");