perf(serverless): lazy-load boto3, fastapi, and pydantic to reduce cold start time

docs/serverless/utils/rp_upload.md

@@ -4,6 +4,14 @@ The upload utility provides functions to upload files and in-memory objects to a
 
 *Note: The upload utility utilizes the Virtual-hosted-style URL with the bucket name in the host name. For example, `https: // bucket-name.s3.amazonaws.com`.*
 
+## Requirements
+
+The upload utility requires [boto3](https://pypi.org/project/boto3/) for S3 functionality. boto3 is lazy-loaded to minimize initial import time and memory footprint.
+
+If you attempt to use S3 upload features without boto3 installed or S3 credentials are not configured, files will be saved to local disk instead:
+- `upload_image()` saves to `simulated_uploaded/` directory
+- `upload_file_to_bucket()` and `upload_in_memory_object()` save to `local_upload/` directory
+
 ## Bucket Credentials
 
 You can set your S3 bucket credentials in the following ways:

runpod/serverless/modules/rp_scale.py

@@ -195,7 +195,7 @@ async def get_jobs(self, session: ClientSession):
 
             except TooManyRequests:
                 log.debug(
-                    f"JobScaler.get_jobs | Too many requests. Debounce for 5 seconds."
+                    "JobScaler.get_jobs | Too many requests. Debounce for 5 seconds."
                 )
                 await asyncio.sleep(5)  # debounce for 5 seconds
             except asyncio.CancelledError:

runpod/serverless/utils/rp_upload.py

@@ -10,20 +10,33 @@
 import threading
 import time
 import uuid
-from typing import Optional, Tuple
+from typing import Any, Optional, Tuple
 from urllib.parse import urlparse
 
-import boto3
-from boto3 import session
-from boto3.s3.transfer import TransferConfig
-from botocore.config import Config
 from tqdm_loggable.auto import tqdm
 
 logger = logging.getLogger("runpod upload utility")
 FMT = "%(filename)-20s:%(lineno)-4d %(asctime)s %(message)s"
 logging.basicConfig(level=logging.INFO, format=FMT, handlers=[logging.StreamHandler()])
 
 
+def _import_boto3_dependencies():
+    """
+    Lazy-load boto3 dependencies.
+    Returns tuple of (session, TransferConfig, Config) or raises ImportError.
+    """
+    try:
+        from boto3 import session
+        from boto3.s3.transfer import TransferConfig
+        from botocore.config import Config
+        return session, TransferConfig, Config
+    except ImportError as e:
+        raise ImportError(
+            "boto3 is required for S3 upload functionality. "
+            "Install with: pip install boto3"
+        ) from e
+
+
 def extract_region_from_url(endpoint_url):
     """
     Extracts the region from the endpoint URL.
@@ -43,12 +56,20 @@ def extract_region_from_url(endpoint_url):
 # --------------------------- S3 Bucket Connection --------------------------- #
 def get_boto_client(
     bucket_creds: Optional[dict] = None,
-) -> Tuple[
-    boto3.client, TransferConfig
-]:  # pragma: no cover # pylint: disable=line-too-long
+) -> Tuple[Any, Any]:  # pragma: no cover # pylint: disable=line-too-long
     """
     Returns a boto3 client and transfer config for the bucket.
+    Lazy-loads boto3 to reduce initial import time.
     """
+    try:
+        session, TransferConfig, Config = _import_boto3_dependencies()
+    except ImportError:
+        logger.warning(
+            "boto3 not installed. S3 upload functionality disabled. "
+            "Install with: pip install boto3"
+        )
+        return None, None
+
     bucket_session = session.Session()
 
     boto_config = Config(
@@ -112,11 +133,11 @@ def upload_image(
 
     if boto_client is None:
         # Save the output to a file
-        print("No bucket endpoint set, saving to disk folder 'simulated_uploaded'")
-        print("If this is a live endpoint, please reference the following:")
-        print(
+        logger.warning(
+            "No bucket endpoint set, saving to disk folder 'simulated_uploaded'. "
+            "If this is a live endpoint, please reference: "
             "https://github.com/runpod/runpod-python/blob/main/docs/serverless/utils/rp_upload.md"
-        )  # pylint: disable=line-too-long
+        )
 
         os.makedirs("simulated_uploaded", exist_ok=True)
         sim_upload_location = f"simulated_uploaded/{image_name}{file_extension}"
@@ -180,6 +201,15 @@ def bucket_upload(job_id, file_list, bucket_creds):  # pragma: no cover
     """
     Uploads files to bucket storage.
     """
+    try:
+        session, _, Config = _import_boto3_dependencies()
+    except ImportError:
+        logger.error(
+            "boto3 not installed. Cannot upload to S3 bucket. "
+            "Install with: pip install boto3"
+        )
+        raise
+
     temp_bucket_session = session.Session()
 
     temp_boto_config = Config(
@@ -231,11 +261,11 @@ def upload_file_to_bucket(
     key = f"{prefix}/{file_name}" if prefix else file_name
 
     if boto_client is None:
-        print("No bucket endpoint set, saving to disk folder 'local_upload'")
-        print("If this is a live endpoint, please reference the following:")
-        print(
+        logger.warning(
+            "No bucket endpoint set, saving to disk folder 'local_upload'. "
+            "If this is a live endpoint, please reference: "
             "https://github.com/runpod/runpod-python/blob/main/docs/serverless/utils/rp_upload.md"
-        )  # pylint: disable=line-too-long
+        )
 
         os.makedirs("local_upload", exist_ok=True)
         local_upload_location = f"local_upload/{file_name}"
@@ -285,6 +315,20 @@ def upload_in_memory_object(
 
     key = f"{prefix}/{file_name}" if prefix else file_name
 
+    if boto_client is None:
+        logger.warning(
+            "No bucket endpoint set, saving to disk folder 'local_upload'. "
+            "If this is a live endpoint, please reference: "
+            "https://github.com/runpod/runpod-python/blob/main/docs/serverless/utils/rp_upload.md"
+        )
+
+        os.makedirs("local_upload", exist_ok=True)
+        local_upload_location = f"local_upload/{file_name}"
+        with open(local_upload_location, "wb") as file_output:
+            file_output.write(file_data)
+
+        return local_upload_location
+
     file_size = len(file_data)
     with tqdm(
         total=file_size, unit="B", unit_scale=True, desc=file_name

tests/test_serverless/test_utils/test_upload.py

@@ -39,9 +39,9 @@ def test_get_boto_client(self):
         # Define the bucket credentials
         bucket_creds = BUCKET_CREDENTIALS
 
-        # Mock boto3.session.Session
+        # Mock boto3 imports (now lazy-loaded inside the function)
         with patch("boto3.session.Session") as mock_session, patch(
-            "runpod.serverless.utils.rp_upload.TransferConfig"
+            "boto3.s3.transfer.TransferConfig"
         ) as mock_transfer_config:
             mock_session.return_value.client.return_value = self.mock_boto_client
             mock_transfer_config.return_value = self.mock_transfer_config
@@ -110,8 +110,9 @@ def test_get_boto_client_environ(self):
 
         importlib.reload(rp_upload)
 
+        # Mock boto3 imports (now lazy-loaded inside the function)
         with patch("boto3.session.Session") as mock_session, patch(
-            "runpod.serverless.utils.rp_upload.TransferConfig"
+            "boto3.s3.transfer.TransferConfig"
         ) as mock_transfer_config:
             mock_session.return_value.client.return_value = self.mock_boto_client
             mock_transfer_config.return_value = self.mock_transfer_config