chore(ci): add ruff and mypy, wire them into CI

Back the shipped py.typed promise with an enforced type check and a linter:

- Add ruff + mypy (+ types-requests) to the dev extras and dev requirements,
  with [tool.ruff]/[tool.mypy] config in pyproject.toml (mypy checks the
  package, not the tests).
- Add a lint job to the Forgejo workflow running ruff check + mypy.
- Fix the issues this surfaced: type FileLock.fd as TextIO | None, add a
  targeted type: ignore for the intentional socket.getaddrinfo monkeypatch,
  and drop an unused import.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.forgejo/workflows/ci.yml

@@ -6,6 +6,24 @@ on:
   pull_request:
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install package with dev extras
+        run: pip install -e ".[dev]"
+
+      - name: Ruff (lint)
+        run: ruff check src/ tests/
+
+      - name: Mypy (type check)
+        run: mypy
+
   test:
     runs-on: ubuntu-latest
     strategy:

pyproject.toml

@@ -17,6 +17,9 @@ dependencies = [
 [project.optional-dependencies]
 dev = [
     "pytest>=7.4",
+    "ruff>=0.6",
+    "mypy>=1.11",
+    "types-requests",
 ]
 
 [project.scripts]
@@ -27,3 +30,13 @@ where = ["src"]
 
 [tool.setuptools.package-data]
 llamacppctl = ["py.typed"]
+
+[tool.ruff]
+target-version = "py310"
+line-length = 100
+
+[tool.mypy]
+python_version = "3.10"
+files = ["src/llamacppctl"]
+warn_unused_ignores = true
+warn_redundant_casts = true

requirements-dev.txt

@@ -2,3 +2,6 @@
 # in pyproject.toml).
 -r requirements.txt
 pytest>=7.4
+ruff>=0.6
+mypy>=1.11
+types-requests

src/llamacppctl/docker_ops.py

@@ -11,7 +11,6 @@ import shlex
 import subprocess
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Optional
 
 from .schema import ServerConfig
 

src/llamacppctl/lock_ops.py

@@ -8,6 +8,7 @@ from __future__ import annotations
 
 import fcntl
 from pathlib import Path
+from typing import TextIO
 
 
 class LockError(RuntimeError):
@@ -17,7 +18,7 @@ class LockError(RuntimeError):
 class FileLock:
     def __init__(self, path: Path):
         self.path = Path(path)
-        self.fd = None
+        self.fd: TextIO | None = None
 
     def __enter__(self) -> "FileLock":
         self.path.parent.mkdir(parents=True, exist_ok=True)

src/llamacppctl/prompt_io.py

@@ -202,7 +202,10 @@ def _pin_dns(host: str, allowed_ips: list):
                 )
         return results
 
-    socket.getaddrinfo = pinned
+    # Intentional monkeypatch: pin DNS to the pre-validated addresses for the
+    # duration of the request (SSRF/rebinding defense). Signature differs from
+    # the stdlib function, hence the targeted ignore.
+    socket.getaddrinfo = pinned  # type: ignore[assignment]
     try:
         yield
     finally: