feat(telemtry): Moved from logs to tracing

- Updated docs

src/lib.rs

@@ -1,3 +1,4 @@
 pub mod configuration;
 pub mod routes;
 pub mod startup;
+pub mod telemetry;

src/main.rs

@@ -1,14 +1,15 @@
 use std::net::TcpListener;
 
+use email_newsletter_api::telemetry::{get_subscriber, init_subscriber};
 use email_newsletter_api::{configuration::get_configuration, startup};
-use env_logger::Env;
 use sqlx::PgPool;
 
 #[tokio::main]
 async fn main() -> Result<(), std::io::Error> {
     let configuration = get_configuration().expect("Failed to read configuration");
 
-    env_logger::Builder::from_env(Env::default().default_filter_or("info")).init();
+    let subscriber = get_subscriber("email_newsletter_api".into(), "info".into());
+    init_subscriber(subscriber);
 
     let db_conn = PgPool::connect(&configuration.database.connection_string())
         .await

src/routes/subscriptions.rs

@@ -1,6 +1,7 @@
 use actix_web::{web, HttpResponse};
 use chrono::Utc;
 use sqlx::PgPool;
+use tracing::Instrument;
 use uuid::Uuid;
 
 #[derive(serde::Deserialize)]
@@ -15,13 +16,17 @@ pub async fn subscribe_route(
 ) -> HttpResponse {
     let request_id = Uuid::new_v4();
 
-    log::info!(
-        "request_id {} - Saving '{}' '{}' as a new subscriber in PostgreSQL",
-        request_id,
-        form.name,
-        form.email
+    let request_span = tracing::info_span!(
+        "Adding new subscriber",
+        %request_id,
+        subscriber_email = %form.email,
+        subscriber_name = %form.name
     );
 
+    let _request_span_guard = request_span.enter();
+
+    let query_span = tracing::info_span!("Adding new subscriber in PostgreSQL");
+
     match sqlx::query!(
         r#"
             INSERT INTO subscriptions (id, email, name, subscribed_at)
@@ -33,17 +38,12 @@ pub async fn subscribe_route(
         Utc::now()
     )
     .execute(db_conn_pool.get_ref())
+    .instrument(query_span)
     .await
     {
-        Ok(_) => {
-            log::info!(
-                "request_id {} - Saved new subscriber details in PostgreSQL",
-                request_id
-            );
-            HttpResponse::Ok().finish()
-        }
+        Ok(_) => HttpResponse::Ok().finish(),
         Err(err) => {
-            log::info!(
+            tracing::error!(
                 "request_id {} - Failed to execute query: {:?}",
                 request_id,
                 err

src/telemetry.rs

@@ -0,0 +1,21 @@
+use tracing::subscriber::set_global_default;
+use tracing::Subscriber;
+use tracing_bunyan_formatter::{BunyanFormattingLayer, JsonStorageLayer};
+use tracing_log::LogTracer;
+use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
+
+pub fn get_subscriber(name: String, env_filter: String) -> impl Subscriber + Send + Sync {
+    let env_filter =
+        EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(env_filter));
+    let formatting_layer = BunyanFormattingLayer::new(name, std::io::stdout);
+    Registry::default()
+        .with(env_filter)
+        .with(JsonStorageLayer)
+        .with(formatting_layer)
+}
+
+// init_subscriber should only be called once
+pub fn init_subscriber(subscriber: impl Subscriber + Send + Sync) {
+    LogTracer::init().expect("Failed to set logger");
+    set_global_default(subscriber).expect("Failed to set subscriber");
+}