fix: Initialize Sentry before tokio

The way Sentry does its Hub/Client-propagation across threads means that it has to be initialized on the main thread for this to work, before any other threads are being spawned.

In other words, Sentry is notorious for being incompatible with `#[tokio::main]`. So lets split the main function into a sync portion initializing all the observability crates, before spawning the tokio runtime and the main server.

Author: Swatinem

objectstore-server/src/main.rs

@@ -17,35 +17,37 @@ mod http;
 mod observability;
 mod state;
 
-#[tokio::main]
-async fn main() -> Result<()> {
+fn main() -> Result<()> {
     let config = Config::from_env()?;
+    tracing::debug!(?config, "Starting service");
 
     // Ensure a rustls crypto provider is installed, required on distroless.
     rustls::crypto::ring::default_provider()
         .install_default()
         .expect("Failed to install rustls crypto provider");
 
-    let metrics_guard = maybe_initialize_metrics(&config)?;
     let _sentry_guard = maybe_initialize_sentry(&config);
+    let metrics_guard = maybe_initialize_metrics(&config)?;
     initialize_tracing(&config);
 
-    tracing::debug!(?config, "Starting service");
-    let state = State::new(config).await?;
-    tokio::spawn(http::server(state));
+    let runtime = tokio::runtime::Runtime::new()?;
+    runtime.block_on(async move {
+        let state = State::new(config).await?;
+        tokio::spawn(http::server(state));
 
-    elegant_departure::tokio::depart()
-        .on_termination()
-        .on_sigint()
-        .on_signal(SignalKind::hangup())
-        .on_signal(SignalKind::quit())
-        .await;
+        elegant_departure::tokio::depart()
+            .on_termination()
+            .on_sigint()
+            .on_signal(SignalKind::hangup())
+            .on_signal(SignalKind::quit())
+            .await;
 
-    if let Some(metrics_guard) = metrics_guard {
-        metrics_guard.flush(None).await?;
-    }
+        if let Some(metrics_guard) = metrics_guard {
+            metrics_guard.flush(None).await?;
+        }
 
-    tracing::info!("shutting down");
+        tracing::info!("shutting down");
 
-    Ok(())
+        Ok(())
+    })
 }