Refactor initializing tracing-subscriber

examples/sessions/src/main.rs

@@ -22,18 +22,17 @@ use axum::{
 use serde::{Deserialize, Serialize};
 use std::fmt::Debug;
 use std::net::SocketAddr;
-use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 use uuid::Uuid;
 
 const AXUM_SESSION_COOKIE_NAME: &str = "axum_session";
 
 #[tokio::main]
 async fn main() {
-    tracing_subscriber::registry()
-        .with(tracing_subscriber::EnvFilter::new(
-            std::env::var("RUST_LOG").unwrap_or_else(|_| "example_sessions=debug".into()),
-        ))
-        .with(tracing_subscriber::fmt::layer())
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            tracing_subscriber::EnvFilter::try_from_default_env()
+                .unwrap_or_else(|_| "example_sessions=debug".into()),
+        )
         .init();
 
     // `MemoryStore` just used as an example. Don't use this in production.