[pve-devel] [PATCH installer 5/7] tui: install progress: handle errors in ui message loop more gracefully

[Christoph Heiss <c.heiss@proxmox.com>]

This at least gives /some/ feedback to the user he can potentially
report, instead of a single, hardcoded message.

Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>
---
 .../src/views/install_progress.rs             | 33 +++++++++++++------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/proxmox-tui-installer/src/views/install_progress.rs b/proxmox-tui-installer/src/views/install_progress.rs
index 3046a26..2025a4c 100644
--- a/proxmox-tui-installer/src/views/install_progress.rs
+++ b/proxmox-tui-installer/src/views/install_progress.rs
@@ -149,29 +149,36 @@ fn progress_task(
     };
 
     let inner = || {
-        let reader = child.stdout.take().map(BufReader::new)?;
-        let mut writer = child.stdin.take()?;
+        let reader = child
+            .stdout
+            .take()
+            .map(BufReader::new)
+            .ok_or("failed to get stdin reader")?;
 
-        serde_json::to_writer(&mut writer, &InstallConfig::from(options)).unwrap();
-        writeln!(writer).unwrap();
+        let mut writer = child.stdin.take().ok_or("failed to get stdin writer")?;
+
+        serde_json::to_writer(&mut writer, &InstallConfig::from(options))
+            .map_err(|err| format!("failed to serialize install config: {err}"))?;
+        writeln!(writer).map_err(|err| format!("failed to write install config: {err}"))?;
 
         let writer = Arc::new(Mutex::new(writer));
 
         for line in reader.lines() {
             let line = match line {
                 Ok(line) => line,
-                Err(_) => break,
+                Err(err) => return Err(format!("low-level installer exited early: {err}")),
             };
 
             let msg = match line.parse::<UiMessage>() {
                 Ok(msg) => msg,
                 Err(stray) => {
+                    // Not a fatal error, so don't abort the installation by returning
                     eprintln!("low-level installer: {stray}");
                     continue;
                 }
             };
 
-            match msg {
+            let result = match msg.clone() {
                 UiMessage::Info(s) => cb_sink.send(Box::new(|siv| {
                     siv.add_layer(Dialog::info(s).title("Information"));
                 })),
@@ -192,18 +199,23 @@ fn progress_task(
                     progress_text.set_content(msg.to_owned());
                     cb_sink.send(Box::new(move |siv| prepare_for_reboot(siv, success, &msg)))
                 }
+            };
+
+            if let Err(err) = result {
+                eprintln!("error during message handling: {err}");
+                eprintln!("  message was: '{msg:?}'");
             }
-            .unwrap();
         }
 
-        Some(())
+        Ok(())
     };
 
-    if inner().is_none() {
+    if let Err(err) = inner() {
+        let message = format!("install failed: {err}");
         cb_sink
             .send(Box::new(|siv| {
                 siv.add_layer(
-                    Dialog::text("low-level installer exited early")
+                    Dialog::text(message)
                         .title("Error")
                         .button("Exit", Cursive::quit),
                 );
@@ -216,6 +228,7 @@ impl ViewWrapper for InstallProgressView {
     cursive::wrap_impl!(self.view: PaddedView<LinearLayout>);
 }
 
+#[derive(Debug, Clone)]
 enum UiMessage {
     Info(String),
     Error(String),
-- 
2.41.0