[pve-devel] [PATCH installer] auto: add some error context when loading the first-boot executable

[Christoph Heiss]

At least to one user in the forum already ran into this IIRC, and most
recently Maximiliano too.

This can happen when e.g. copying example answer files with the
first-boot section, without then passing `--on-first-boot` to
proxmox-auto-install-assistant.

In that case, the user would just get a pretty unhelpful error message:

  ERROR: Autoinstaller setup error: No such file or directory (os error 2)

Attach some context, which points the user directly to the corresponding
setting / answer file section.

Reported-by: Maximiliano Sandoval <m.sandoval at proxmox.com>
Signed-off-by: Christoph Heiss <c.heiss at proxmox.com>
---
 proxmox-auto-installer/src/bin/proxmox-auto-installer.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/proxmox-auto-installer/src/bin/proxmox-auto-installer.rs b/proxmox-auto-installer/src/bin/proxmox-auto-installer.rs
index 05d1801..b248dff 100644
--- a/proxmox-auto-installer/src/bin/proxmox-auto-installer.rs
+++ b/proxmox-auto-installer/src/bin/proxmox-auto-installer.rs
@@ -1,4 +1,4 @@
-use anyhow::{Result, bail, format_err};
+use anyhow::{Context, Result, bail, format_err};
 use log::{LevelFilter, error, info};
 use std::{
     env,
@@ -47,7 +47,9 @@ fn setup_first_boot_executable(first_boot: &FirstBootHookInfo) -> Result<()> {
             }
         }
         FirstBootHookSourceMode::FromIso => {
-            Some(fs::read(format!("/cdrom/{FIRST_BOOT_EXEC_NAME}"))?)
+            Some(fs::read(format!("/cdrom/{FIRST_BOOT_EXEC_NAME}")).context(
+                "failed loading first-boot executable from ISO (was --on-first-boot specified?)",
+            )?)
         }
     };
 
@@ -115,7 +117,7 @@ fn main() -> ExitCode {
     let (answer, udevadm_info) = match auto_installer_setup(in_test_mode) {
         Ok(result) => result,
         Err(err) => {
-            error!("Autoinstaller setup error: {err}");
+            error!("Autoinstaller setup error: {err:#}");
             return ExitCode::FAILURE;
         }
     };
-- 
2.48.1