Bring over some overlord minion-exit handling we forgot from the tauri branch

src/overlord/mod.rs

@@ -13,13 +13,16 @@ use std::collections::HashMap;
 use tokio::sync::broadcast::Sender;
 use tokio::sync::mpsc::UnboundedReceiver;
 use tokio::{select, task};
-use tracing::{debug, error, info};
+use tracing::{debug, error, info, warn};
 
 pub struct Overlord {
     settings: Settings,
     to_minions: Sender<BusMessage>,
     from_minions: UnboundedReceiver<BusMessage>,
+
+    // All the minion tasks running.
     minions: task::JoinSet<()>,
+
     minions_task_url: HashMap<task::Id, Url>,
     #[allow(dead_code)]
     private_key: Option<PrivateKey>, // note that PrivateKey already zeroizes on drop
@@ -217,6 +220,44 @@ impl Overlord {
                 };
                 keepgoing = self.handle_bus_message(bus_message).await?;
             },
+            task_next_joined = self.minions.join_next_with_id() => {
+                if task_next_joined.is_none() {
+                    return Ok(true); // rare but possible
+                }
+                match task_next_joined.unwrap() {
+                    Err(join_error) => {
+                        let id = join_error.id();
+                        let maybe_url = self.minions_task_url.get(&id);
+                        match maybe_url {
+                            Some(url) => {
+                                // JoinError also has is_cancelled, is_panic, into_panic, try_into_panic
+                                // Minion probably alreaedy logged, this may be redundant.
+                                warn!("Minion {} completed with error: {}", &url, join_error);
+
+                                // Minion probably already logged failure in relay table
+
+                                // Remove from our hashmap
+                                self.minions_task_url.remove(&id);
+                            },
+                            None => {
+                                warn!("Minion UNKNOWN completed with error: {}", join_error);
+                            }
+                        }
+                    },
+                    Ok((id, _)) => {
+                        let maybe_url = self.minions_task_url.get(&id);
+                        match maybe_url {
+                            Some(url) => {
+                                warn!("Relay Task {} completed", &url);
+
+                                // Remove from our hashmap
+                                self.minions_task_url.remove(&id);
+                            },
+                            None => warn!("Relay Task UNKNOWN completed"),
+                        }
+                    }
+                }
+            }
         }
 
         Ok(keepgoing)
@@ -244,6 +285,7 @@ impl Overlord {
             "overlord" => match &*bus_message.kind {
                 "minion_is_ready" => {}
                 "save_settings" => {
+                    // from ui
                     let settings: Settings = serde_json::from_str(&bus_message.json_payload)?;
 
                     // Save to database