[pve-devel] [PATCH pve-esxi-import-tools v2 1/1] improve error handling before mounting

[Dominik Csapak]

when we fail early in the mount process, we did not log any error to the
syslog, but only the top most one to stderr.

sadly we were not able to see them anywhere, so improve the log by
* log the complete error chain with log::error (so we also can see the
  causes)
* add more context hints

This can help debug issues where we failed early and could not see any
error output otherwise, e.g. this thread in the forum:

https://forum.proxmox.com/threads/146248/

Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
 src/esxi.rs |  7 ++++++-
 src/main.rs | 15 +++++++++++----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/esxi.rs b/src/esxi.rs
index 6be9466..88930b0 100644
--- a/src/esxi.rs
+++ b/src/esxi.rs
@@ -278,7 +278,12 @@ impl EsxiClient {
     ) -> Result<EsxiFile, Error> {
         log::debug!("open file [{datacenter}, {datastore}] {path:?}");
         let query = self.file_url(datacenter, datastore, path);
-        let size = self.get_file_size(datacenter, datastore, path).await?;
+        let size = self
+            .get_file_size(datacenter, datastore, path)
+            .await
+            .with_context(|| {
+                format!("error when getting file size: {datacenter:?}/{datastore:?}/{path:?}")
+            })?;
         Ok(EsxiFile {
             client: Arc::clone(self),
             query: query.into(),
diff --git a/src/main.rs b/src/main.rs
index 281ec3d..216173d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,5 @@
 use std::ffi::{CString, OsStr, OsString};
+use std::fmt::Write;
 use std::io;
 use std::os::fd::RawFd;
 use std::os::unix::ffi::OsStrExt;
@@ -221,7 +222,12 @@ fn main() {
     });
 
     if let Err(err) = runtime.block_on(main_do()) {
-        eprintln!("Error: {}", err);
+        let mut err_chain = String::new();
+        for err in err.chain() {
+            let _ = writeln!(err_chain, " {err}");
+        }
+        eprintln!("Error: {err}");
+        log::error!("Error:{err_chain}");
         std::process::exit(-1);
     }
 }
@@ -302,9 +308,10 @@ async fn main_do() -> Result<(), Error> {
             let fs_datastore = fs_datacenter.create_datastore(datastore);
 
             log::debug!("loading {datacenter:?}/{datastore:?}/{path:?}");
-            let config =
-                vmx::VmConfig::parse(client.open_file(datacenter, datastore, path).await?, path)
-                    .await?;
+            let config = client.open_file(datacenter, datastore, path).await?;
+            let config = vmx::VmConfig::parse(config, path).await.with_context(|| {
+                format!("error when parsing VM config: {datacenter:?}/{datastore:?}/{path:?}")
+            })?;
             log::debug!("{config:#?}");
             for disk in config.disks.values() {
                 let other_fs_datastore;
-- 
2.39.2