feat: download lora adapter weights from launcher (#2140)

launcher/src/main.rs

@@ -898,13 +898,20 @@ enum LauncherError {
     WebserverCannotStart,
 }
 
-fn download_convert_model(args: &Args, running: Arc<AtomicBool>) -> Result<(), LauncherError> {
+fn download_convert_model(
+    model_id: &str,
+    revision: Option<&str>,
+    trust_remote_code: bool,
+    huggingface_hub_cache: Option<&str>,
+    weights_cache_override: Option<&str>,
+    running: Arc<AtomicBool>,
+) -> Result<(), LauncherError> {
     // Enter download tracing span
     let _span = tracing::span!(tracing::Level::INFO, "download").entered();
 
     let mut download_args = vec![
         "download-weights".to_string(),
-        args.model_id.to_string(),
+        model_id.to_string(),
         "--extension".to_string(),
         ".safetensors".to_string(),
         "--logger-level".to_string(),
@@ -913,13 +920,13 @@ fn download_convert_model(args: &Args, running: Arc<AtomicBool>) -> Result<(), L
     ];
 
     // Model optional revision
-    if let Some(revision) = &args.revision {
+    if let Some(revision) = &revision {
         download_args.push("--revision".to_string());
         download_args.push(revision.to_string())
     }
 
     // Trust remote code for automatic peft fusion
-    if args.trust_remote_code {
+    if trust_remote_code {
         download_args.push("--trust-remote-code".to_string());
     }
 
@@ -934,7 +941,7 @@ fn download_convert_model(args: &Args, running: Arc<AtomicBool>) -> Result<(), L
 
     // If huggingface_hub_cache is set, pass it to the download process
     // Useful when running inside a docker container
-    if let Some(ref huggingface_hub_cache) = args.huggingface_hub_cache {
+    if let Some(ref huggingface_hub_cache) = huggingface_hub_cache {
         envs.push(("HUGGINGFACE_HUB_CACHE".into(), huggingface_hub_cache.into()));
     };
 
@@ -952,15 +959,15 @@ fn download_convert_model(args: &Args, running: Arc<AtomicBool>) -> Result<(), L
 
     // If args.weights_cache_override is some, pass it to the download process
     // Useful when running inside a HuggingFace Inference Endpoint
-    if let Some(weights_cache_override) = &args.weights_cache_override {
+    if let Some(weights_cache_override) = &weights_cache_override {
         envs.push((
             "WEIGHTS_CACHE_OVERRIDE".into(),
             weights_cache_override.into(),
         ));
     };
 
     // Start process
-    tracing::info!("Starting download process.");
+    tracing::info!("Starting check and download process for {model_id}");
     let mut download_process = match Command::new("text-generation-server")
         .args(download_args)
         .env_clear()
@@ -1002,7 +1009,7 @@ fn download_convert_model(args: &Args, running: Arc<AtomicBool>) -> Result<(), L
     loop {
         if let Some(status) = download_process.try_wait().unwrap() {
             if status.success() {
-                tracing::info!("Successfully downloaded weights.");
+                tracing::info!("Successfully downloaded weights for {model_id}");
                 break;
             }
 
@@ -1557,7 +1564,28 @@ fn main() -> Result<(), LauncherError> {
     .expect("Error setting Ctrl-C handler");
 
     // Download and convert model weights
-    download_convert_model(&args, running.clone())?;
+    download_convert_model(
+        &args.model_id,
+        args.revision.as_deref(),
+        args.trust_remote_code,
+        args.huggingface_hub_cache.as_deref(),
+        args.weights_cache_override.as_deref(),
+        running.clone(),
+    )?;
+
+    // Download and convert lora adapters if any
+    if let Some(lora_adapters) = &args.lora_adapters {
+        for adapter in lora_adapters.split(',') {
+            download_convert_model(
+                adapter,
+                None,
+                args.trust_remote_code,
+                args.huggingface_hub_cache.as_deref(),
+                args.weights_cache_override.as_deref(),
+                running.clone(),
+            )?;
+        }
+    }
 
     if !running.load(Ordering::SeqCst) {
         // Launcher was asked to stop