Add some explanationes on wait's tracing and use tokio_async_drop for…

… c8d leases

Signed-off-by: Jorge Prendes <jorge.prendes@gmail.com>

crates/containerd-shim-wasm/src/sandbox/containerd/lease.rs

@@ -7,6 +7,7 @@ use containerd_client::services::v1::DeleteRequest;
 use containerd_client::services::v1::leases_client::LeasesClient;
 use containerd_client::tonic::transport::Channel;
 use containerd_client::{tonic, with_namespace};
+use tokio_async_drop::tokio_async_drop;
 use tonic::Request;
 
 // Adds lease info to grpc header
@@ -74,7 +75,7 @@ impl LeaseGuardInner {
 impl Drop for LeaseGuard {
     fn drop(&mut self) {
         let inner = self.inner.take().unwrap();
-        tokio::spawn(async move {
+        tokio_async_drop!({
             match inner.release().await {
                 Ok(()) => log::info!("removed lease"),
                 Err(err) => log::warn!("error removing lease: {err}"),

crates/containerd-shim-wasm/src/sandbox/shim/local.rs

@@ -433,6 +433,12 @@ impl<T: Instance + Sync + Send, E: EventSender> Task for Local<T, E> {
             let parent_span = Span::current();
             parent_span.set_parent(extract_context(&_ctx.metadata));
 
+            // This future never completes as it runs an infinite loop.
+            // It will stop executing when dropped.
+            // We need to keep this future's lifetime tied to this
+            // method's lifetime.
+            // This means we shouldn't tokio::spawn it, but ruther
+            // tokio::select! it inside of this async method.
             async move {
                 loop {
                     let current_span =