proxy: add some connection init logs (#4812)

## Problem

The first session event we emit is after we receive the first startup
packet from the client. This means we can't detect any issues between
TCP open and handling of the first PG packet

## Summary of changes

Add some new logs for websocket upgrade and connection handling

proxy/src/http/websocket.rs

@@ -181,13 +181,15 @@ async fn ws_handler(
 
     // Check if the request is a websocket upgrade request.
     if hyper_tungstenite::is_upgrade_request(&request) {
+        info!(session_id = ?session_id, "performing websocket upgrade");
+
         let (response, websocket) = hyper_tungstenite::upgrade(&mut request, None)
             .map_err(|e| ApiError::BadRequest(e.into()))?;
 
         tokio::spawn(async move {
             if let Err(e) = serve_websocket(websocket, config, &cancel_map, session_id, host).await
             {
-                error!("error in websocket connection: {e:?}");
+                error!(session_id = ?session_id, "error in websocket connection: {e:?}");
             }
         });
 

proxy/src/proxy.rs

@@ -196,6 +196,11 @@ pub async fn handle_client<S: AsyncRead + AsyncWrite + Unpin>(
     stream: S,
     mode: ClientMode,
 ) -> anyhow::Result<()> {
+    info!(
+        protocol = mode.protocol_label(),
+        "handling interactive connection from client"
+    );
+
     // The `closed` counter will increase when this future is destroyed.
     NUM_CONNECTIONS_ACCEPTED_COUNTER
         .with_label_values(&[mode.protocol_label()])