chore(gui-client): log uptime and run ID when a window is shown (#3913)

I want to make sure there aren't bugs that prevent the GUI clients from
reaching high uptime, so this makes it easy to check the uptime with
e.g. `tail -f`. The run IDs would let us re-construct when the app
restarts.

"chore" doesn't seem right but it's not a user-facing feature, test,
doc, fix, or refactor, either.

Signed-off-by: Reactor Scram <ReactorScram@users.noreply.github.com>

rust/gui-client/src-tauri/src/client.rs

@@ -16,6 +16,7 @@ mod network_changes;
 mod resolvers;
 mod settings;
 mod updates;
+mod uptime;
 
 #[cfg(target_os = "windows")]
 mod wintun_install;

rust/gui-client/src-tauri/src/client/gui.rs

@@ -503,6 +503,7 @@ struct Controller {
     /// Tells us when to wake up and look for a new resource list. Tokio docs say that memory reads and writes are synchronized when notifying, so we don't need an extra mutex on the resources.
     notify_controller: Arc<Notify>,
     tunnel_ready: bool,
+    uptime: client::uptime::Tracker,
 }
 
 /// Everything related to a signed-in user session
@@ -634,7 +635,18 @@ impl Controller {
                     self.sign_out()?;
                 }
             }
-            Req::SystemTrayMenu(TrayMenuEvent::ShowWindow(window)) => self.show_window(window)?,
+            Req::SystemTrayMenu(TrayMenuEvent::ShowWindow(window)) => {
+                self.show_window(window)?;
+                // When the About or Settings windows are hidden / shown, log the
+                // run ID and uptime. This makes it easy to check client stability on
+                // dev or test systems without parsing the whole log file.
+                let uptime_info = self.uptime.info();
+                tracing::debug!(
+                    uptime_s = uptime_info.uptime.as_secs(),
+                    run_id = uptime_info.run_id.to_string(),
+                    "Uptime info"
+                );
+            }
             Req::SystemTrayMenu(TrayMenuEvent::Resource { id }) => self
                 .copy_resource(&id)
                 .context("Couldn't copy resource to clipboard")?,
@@ -784,6 +796,7 @@ async fn run_controller(
         logging_handles,
         notify_controller,
         tunnel_ready: false,
+        uptime: Default::default(),
     };
 
     if let Some(token) = controller

rust/gui-client/src-tauri/src/client/uptime.rs

@@ -0,0 +1,31 @@
+use std::time::Duration;
+use tokio::time::Instant;
+use uuid::Uuid;
+
+pub struct Tracker {
+    run_id: Uuid,
+    start_time: Instant,
+}
+
+pub struct Info {
+    pub run_id: Uuid,
+    pub uptime: Duration,
+}
+
+impl Default for Tracker {
+    fn default() -> Self {
+        Self {
+            start_time: Instant::now(),
+            run_id: Uuid::new_v4(),
+        }
+    }
+}
+
+impl Tracker {
+    pub fn info(&self) -> Info {
+        Info {
+            run_id: self.run_id,
+            uptime: Instant::now() - self.start_time,
+        }
+    }
+}