revert: feat(server): Use system packages for execution (#1551)

Reverts meta-llama/llama-stack#1252

The above PR breaks the following invocation:
```bash
llama stack run ~/.llama/distributions/together/together-run.yaml
```

llama_stack/cli/stack/run.py

@@ -56,6 +56,7 @@ class StackRun(Subcommand):
             "--env",
             action="append",
             help="Environment variables to pass to the server in KEY=VALUE format. Can be specified multiple times.",
+            default=[],
             metavar="KEY=VALUE",
         )
         self.parser.add_argument(
@@ -73,6 +74,7 @@ class StackRun(Subcommand):
             type=str,
             help="Image Type used during the build. This can be either conda or container or venv.",
             choices=["conda", "container", "venv"],
+            default="conda",
         )
 
     def _run_stack_run_cmd(self, args: argparse.Namespace) -> None:
@@ -118,40 +120,18 @@ class StackRun(Subcommand):
         except AttributeError as e:
             self.parser.error(f"failed to parse config file '{config_file}':\n {e}")
 
-        # If neither image type nor image name is provided, assume the server should be run directly
-        # using the current environment packages.
-        if not args.image_type and not args.image_name:
-            logger.info("No image type or image name provided. Assuming environment packages.")
-            from llama_stack.distribution.server.server import main as server_main
-
-            # Build the server args from the current args passed to the CLI
-            server_args = argparse.Namespace()
-            for arg in vars(args):
-                # If this is a function, avoid passing it
-                # "args" contains:
-                # func=<bound method StackRun._run_stack_run_cmd of <llama_stack.cli.stack.run.StackRun object at 0x10484b010>>
-                if callable(getattr(args, arg)):
-                    continue
-                setattr(server_args, arg, getattr(args, arg))
-
-            # Run the server
-            server_main(server_args)
-        else:
         run_args = formulate_run_args(args.image_type, args.image_name, config, template_name)
 
         run_args.extend([str(config_file), str(args.port)])
         if args.disable_ipv6:
             run_args.append("--disable-ipv6")
 
-            if args.env:
         for env_var in args.env:
             if "=" not in env_var:
                 self.parser.error(f"Environment variable '{env_var}' must be in KEY=VALUE format")
-                        return
             key, value = env_var.split("=", 1)  # split on first = only
             if not key:
                 self.parser.error(f"Environment variable '{env_var}' has empty key")
-                        return
             run_args.extend(["--env", f"{key}={value}"])
 
         if args.tls_keyfile and args.tls_certfile:

llama_stack/distribution/server/server.py

@@ -17,7 +17,7 @@ import warnings
 from contextlib import asynccontextmanager
 from importlib.metadata import version as parse_version
 from pathlib import Path
-from typing import Any, List, Optional, Union
+from typing import Any, List, Union
 
 import yaml
 from fastapi import Body, FastAPI, HTTPException, Request
@@ -314,17 +314,11 @@ class ClientVersionMiddleware:
         return await self.app(scope, receive, send)
 
 
-def main(args: Optional[argparse.Namespace] = None):
+def main():
     """Start the LlamaStack server."""
     parser = argparse.ArgumentParser(description="Start the LlamaStack server.")
     parser.add_argument(
         "--yaml-config",
-        dest="config",
-        help="(Deprecated) Path to YAML configuration file - use --config instead",
-    )
-    parser.add_argument(
-        "--config",
-        dest="config",
         help="Path to YAML configuration file",
     )
     parser.add_argument(
@@ -354,20 +348,8 @@ def main(args: Optional[argparse.Namespace] = None):
         required="--tls-keyfile" in sys.argv,
     )
 
-    # Determine whether the server args are being passed by the "run" command, if this is the case
-    # the args will be passed as a Namespace object to the main function, otherwise they will be
-    # parsed from the command line
-    if args is None:
     args = parser.parse_args()
 
-    # Check for deprecated argument usage
-    if "--yaml-config" in sys.argv:
-        warnings.warn(
-            "The '--yaml-config' argument is deprecated and will be removed in a future version. Use '--config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-
     if args.env:
         for env_pair in args.env:
             try:
@@ -378,9 +360,9 @@ def main(args: Optional[argparse.Namespace] = None):
                 logger.error(f"Error: {str(e)}")
                 sys.exit(1)
 
-    if args.config:
+    if args.yaml_config:
         # if the user provided a config file, use it, even if template was specified
-        config_file = Path(args.config)
+        config_file = Path(args.yaml_config)
         if not config_file.exists():
             raise ValueError(f"Config file {config_file} does not exist")
         logger.info(f"Using config file: {config_file}")