Coverage for mcpgateway/cli.py: 97%
29 statements
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« prev ^ index » next coverage.py v7.9.1, created at 2025-06-22 12:51 +0100
1# -*- coding: utf-8 -*-
2"""mcpgateway CLI ─ a thin wrapper around Uvicorn
4Copyright 2025
5SPDX-License-Identifier: Apache-2.0
6Authors: Mihai Criveti
8This module is exposed as a **console-script** via:
10 [project.scripts]
11 mcpgateway = "mcpgateway.cli:main"
13so that a user can simply type `mcpgateway …` instead of the longer
14`uvicorn mcpgateway.main:app …`.
16Features
17─────────
18* Injects the default FastAPI application path (``mcpgateway.main:app``)
19 when the user doesn't supply one explicitly.
20* Adds sensible default host/port (127.0.0.1:4444) unless the user passes
21 ``--host``/``--port`` or overrides them via the environment variables
22 ``MCG_HOST`` and ``MCG_PORT``.
23* Forwards *all* remaining arguments verbatim to Uvicorn's own CLI, so
24 `--reload`, `--workers`, etc. work exactly the same.
26Typical usage
27─────────────
28```console
29$ mcpgateway --reload # dev server on 127.0.0.1:4444
30$ mcpgateway --workers 4 # production-style multiprocess
31$ mcpgateway 127.0.0.1:8000 --reload # explicit host/port keeps defaults out
32$ mcpgateway mypkg.other:app # run a different ASGI callable
33```
34"""
36from __future__ import annotations
38import os
39import sys
40from typing import List
42import uvicorn
44from mcpgateway import __version__
46# ---------------------------------------------------------------------------
47# Configuration defaults (overridable via environment variables)
48# ---------------------------------------------------------------------------
49DEFAULT_APP = "mcpgateway.main:app" # dotted path to FastAPI instance
50DEFAULT_HOST = os.getenv("MCG_HOST", "127.0.0.1")
51DEFAULT_PORT = int(os.getenv("MCG_PORT", "4444"))
53# ---------------------------------------------------------------------------
54# Helper utilities
55# ---------------------------------------------------------------------------
58def _needs_app(arg_list: List[str]) -> bool:
59 """Return *True* when the CLI invocation has *no* positional APP path.
61 According to Uvicorn's argument grammar, the **first** non-flag token
62 is taken as the application path. We therefore look at the first
63 element of *arg_list* (if any) – if it *starts* with a dash it must be
64 an option, hence the app path is missing and we should inject ours.
66 Args:
67 arg_list (List[str]): List of arguments
69 Returns:
70 bool: Returns *True* when the CLI invocation has *no* positional APP path
71 """
73 return len(arg_list) == 0 or arg_list[0].startswith("-")
76def _insert_defaults(raw_args: List[str]) -> List[str]:
77 """Return a *new* argv with defaults sprinkled in where needed.
79 Args:
80 raw_args (List[str]): List of input arguments to cli
82 Returns:
83 List[str]: List of arguments
84 """
86 args = list(raw_args) # shallow copy – we'll mutate this
88 # 1️⃣ Ensure an application path is present.
89 if _needs_app(args):
90 args.insert(0, DEFAULT_APP)
92 # 2️⃣ Supply host/port if neither supplied nor UNIX domain socket.
93 if "--uds" not in args:
94 if "--host" not in args and "--http" not in args:
95 args.extend(["--host", DEFAULT_HOST])
96 if "--port" not in args: 96 ↛ 99line 96 didn't jump to line 99 because the condition on line 96 was always true
97 args.extend(["--port", str(DEFAULT_PORT)])
99 return args
102# ---------------------------------------------------------------------------
103# Public entry-point
104# ---------------------------------------------------------------------------
107def main() -> None: # noqa: D401 – imperative mood is fine here
108 """Entry point for the *mcpgateway* console script (delegates to Uvicorn)."""
110 # Check for version flag
111 if "--version" in sys.argv or "-V" in sys.argv:
112 print(f"mcpgateway {__version__}")
113 return
115 # Discard the program name and inspect the rest.
116 user_args = sys.argv[1:]
117 uvicorn_argv = _insert_defaults(user_args)
119 # Uvicorn's `main()` uses sys.argv – patch it in and run.
120 sys.argv = ["mcpgateway", *uvicorn_argv]
121 uvicorn.main()
124if __name__ == "__main__": # pragma: no cover – executed only when run directly
125 main()