Refactor initializing tracing-subscriber

examples/websockets/src/main.rs

@@ -21,16 +21,14 @@ use tower_http::{
     services::ServeDir,
     trace::{DefaultMakeSpan, TraceLayer},
 };
-use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
 #[tokio::main]
 async fn main() {
-    tracing_subscriber::registry()
-        .with(tracing_subscriber::EnvFilter::new(
-            std::env::var("RUST_LOG")
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            tracing_subscriber::EnvFilter::try_from_default_env()
                 .unwrap_or_else(|_| "example_websockets=debug,tower_http=debug".into()),
-        ))
-        .with(tracing_subscriber::fmt::layer())
+        )
         .init();
 
     let assets_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("assets");