code: def upload_to_s3(
      src_path: str, bucket: str, key_path: str
  ) -> Optional[str]:
      """Upload a file to a S3 bucket
  
      This assumes the bucket has public read access on the objects uploaded.
  
      Args:
          src_path: local file path.
          bucket: S3 bucket name.
          key_path: destination url of the uploaded object.
  
      Return:
          HTTP URL where the uploaded object could be downloaded if successful,
          or None if fails.
  
      Raises:
          ClientError if upload fails
      """
      s3_client = boto3.client("s3")
      try:
          s3_client.upload_file(
              Filename=src_path, Bucket=bucket, Key=key_path
          )
      except ClientError as e:
          logger.warning(f"Failed to upload to s3:  {e}")
          return None
  
      return f"https://{bucket}.s3.us-west-2.amazonaws.com/{key_path}"
  
file_path: ray/release/ray_release/aws.py
imports: import os
  from copy import deepcopy
  from typing import Optional
  import boto3
  from botocore.exceptions import ClientError
  from ray_release.logger import logger
  from ray_release.util import DeferredEnvVar
label_desc: Use image node_id 4 for calling a global function with example usage: upload_to_s3(src_path, bucket, key_path) and returns: str, bucket, str, key_path, None