hil: added --overwrite-existing (#208)

hil/src/commands/flash.rs

@@ -6,7 +6,7 @@ use color_eyre::{
 };
 use tracing::info;
 
-use crate::{current_dir, flash::FlashVariant};
+use crate::{current_dir, download_s3::ExistingFileBehavior, flash::FlashVariant};
 
 #[derive(Parser, Debug)]
 pub struct Flash {
@@ -19,14 +19,22 @@ pub struct Flash {
     /// Skips download by using an existing tarball on the filesystem.
     #[arg(long)]
     rts_path: Option<Utf8PathBuf>,
-    /// if this flag is given, uses flashcmd.txt instead of fastflashcmd.txt
+    /// If this flag is given, uses flashcmd.txt instead of fastflashcmd.txt
     #[arg(long)]
     slow: bool,
+    /// If this flag is given, overwites any existing files when downloading the rts.
+    #[arg(long)]
+    overwrite_existing: bool,
 }
 
 impl Flash {
     pub async fn run(self) -> Result<()> {
         let args = self;
+        let existing_file_behavior = if args.overwrite_existing {
+            ExistingFileBehavior::Overwrite
+        } else {
+            ExistingFileBehavior::Abort
+        };
         ensure!(
             crate::boot::is_recovery_mode_detected()?,
             "orb must be in recovery mode to flash. Try running `orb-hil reboot -r`"
@@ -41,9 +49,13 @@ impl Flash {
                     .wrap_err("failed to parse filename")?,
             );
 
-            crate::download_s3::download_url(s3_url, &download_path)
-                .await
-                .wrap_err("error while downloading from s3")?;
+            crate::download_s3::download_url(
+                s3_url,
+                &download_path,
+                existing_file_behavior,
+            )
+            .await
+            .wrap_err("error while downloading from s3")?;
 
             download_path
         } else if let Some(rts_path) = args.rts_path {

hil/src/download_s3.rs

@@ -14,9 +14,23 @@ use indicatif::{ProgressState, ProgressStyle};
 use tempfile::NamedTempFile;
 use tracing::info;
 
+#[derive(Debug, Eq, PartialEq)]
+pub enum ExistingFileBehavior {
+    /// If a file exists, overwrite it
+    Overwrite,
+    /// If a file exists, abort
+    Abort,
+}
+
 /// `out_path` is the final path of the file after downloading.
-pub async fn download_url(url: &str, out_path: &Utf8Path) -> Result<()> {
-    ensure!(!out_path.exists(), "{out_path:?} already exists!");
+pub async fn download_url(
+    url: &str,
+    out_path: &Utf8Path,
+    existing_file_behavior: ExistingFileBehavior,
+) -> Result<()> {
+    if existing_file_behavior == ExistingFileBehavior::Abort {
+        ensure!(!out_path.exists(), "{out_path:?} already exists!");
+    }
     let parent_dir = out_path
         .parent()
         .expect("please provide the path to a file");
@@ -99,6 +113,12 @@ pub async fn download_url(url: &str, out_path: &Utf8Path) -> Result<()> {
     let tmp_file = NamedTempFile::from_parts(tmp_file.into_std().await, tmp_file_path);
     let out_path_clone = out_path.to_owned();
     tokio::task::spawn_blocking(move || {
+        if existing_file_behavior == ExistingFileBehavior::Abort {
+            ensure!(
+                !out_path_clone.exists(),
+                "{out_path_clone:?} already exists!"
+            );
+        }
         tmp_file
             .persist(out_path_clone)
             .wrap_err("failed to persist temporary file")