Pin uvloop<0.22 and add sanity test for it

CHANGES/7213.bugfix

@@ -0,0 +1 @@
+Pinned uvloop (optional dependency) to prevent a known bug in a newer releases.

pulpcore/tests/unit/conftest.py

@@ -1,11 +1,11 @@
 import pytest
 from uuid import uuid4
 
-from pulpcore.app.models import Domain
-from pulpcore.app.util import set_domain
-
 
 @pytest.fixture
 def fake_domain():
     """A fixture to prevent `get_domain` to call out to the database."""
+    from pulpcore.app.models import Domain
+    from pulpcore.app.util import set_domain
+
     set_domain(Domain(pk=uuid4(), name=uuid4()))

pulpcore/tests/unit/test_startup.py

@@ -0,0 +1,105 @@
+"""App startup scenarios which doesn't require a full instance."""
+
+import base64
+import os
+import secrets
+import subprocess
+from textwrap import dedent
+from pathlib import Path
+
+import pytest
+
+
+@pytest.fixture
+def pulpcore_source_dir() -> Path:
+    """The pulpcore source directory (repository root)."""
+    source_dir = Path(__file__).parents[3]
+    lookup_dirs = (
+        Path(__file__).parents[3],
+        Path("/pulpcore"),
+        Path("/src/pulpcore"),
+    )
+    source_dir = None
+    for dir in lookup_dirs:
+        if (dir / "pyproject.toml").exists():
+            source_dir = dir
+            break
+    if not source_dir:
+        raise RuntimeError("Couldn't find pulpcore's source")
+    return source_dir
+
+
+@pytest.fixture
+def pulpcore_dist(pulpcore_source_dir) -> Path | None:
+    pulpcore_dist_glob = list((pulpcore_source_dir / "dist").glob("*.whl"))
+    pulpcore_dist = pulpcore_dist_glob[0] if len(pulpcore_dist_glob) else None
+    return pulpcore_dist
+
+
+@pytest.fixture
+def encryption_key_file(tmp_path: Path) -> Path:
+    """A file with a symmetric encryption key."""
+    key_file = tmp_path / "symmetric.key"
+    key = base64.urlsafe_b64encode(secrets.token_bytes(32))
+    key_file.write_bytes(key)
+    return key_file
+
+
+class TestUvloop:
+    def test_uvloop_startup(
+        self, pulpcore_source_dir: Path, pulpcore_dist: Path | None, pulp_env: dict[str, str]
+    ):
+        """
+        Test that pulpcore-content can start successfully with uvloop enabled.
+        """
+        TIMEOUT_PROGRAM_EXIT_CODE = 124  # means 'timeout N' exited after N seconds
+        ci_constraints = pulpcore_source_dir / ".ci" / "assets" / "ci_constraints.txt"
+        install_source = pulpcore_dist or pulpcore_source_dir
+
+        cmd = [
+            "uv",
+            "run",
+            "--isolated",
+            "--no-project",
+            "--with",
+            f"{str(install_source.resolve())}[uvloop]",
+            "--with-requirements",
+            str(ci_constraints.resolve()),
+            "timeout",
+            "5",
+            "pulpcore-content",
+            "--bind",
+            "127.0.0.1:0",  # Use random available port
+        ]
+
+        result = subprocess.run(cmd, env=pulp_env, capture_output=True)
+
+        stderr = result.stderr.decode()
+        assert result.returncode == TIMEOUT_PROGRAM_EXIT_CODE, (
+            f"pulpcore-content exited prematurely with exit code {result.returncode}.\n"
+            f"Output: {stderr}"
+        )
+        assert "Using uvloop as the asyncio event loop" in stderr
+        assert (
+            "Connection in use:" not in stderr
+        ), "Some other program is using the port shown in stderr"
+
+    @pytest.fixture
+    def settings_file(self, tmp_path: Path, encryption_key_file: Path) -> Path:
+        settings_file = tmp_path / "settings.py"
+        settings_content = f"""
+        UVLOOP_ENABLED = True
+        FILE_UPLOAD_TEMP_DIR = "{tmp_path.resolve()}"
+        WORKING_DIRECTORY = "{tmp_path.resolve()}"
+        DB_ENCRYPTION_KEY = "{encryption_key_file.resolve()}"
+        """
+        settings_file.write_text(dedent(settings_content))
+        return settings_file
+
+    @pytest.fixture
+    def pulp_env(self, settings_file: Path) -> dict[str, str]:
+        """Configured environment."""
+        env = {}
+        env["PATH"] = os.environ["PATH"]  # enable subprocess to find system binaries
+        env["PULP_SETTINGS"] = str(settings_file)
+        return env

pyproject.toml

@@ -79,7 +79,7 @@ kafka = [
   "confluent-kafka>=2.4.0,<2.14.0",
 ]
 diagnostics = ["pyinstrument~=5.0", "memray~=1.17"]
-uvloop = ["uvloop>=0.20,<0.23"]
+uvloop = ["uvloop>=0.20,<0.22"]
 
 [project.urls]
 Homepage = "https://pulpproject.org"

unittest_requirements.txt

@@ -6,3 +6,4 @@ pytest-django
 pytest-asyncio
 pytest-aiohttp
 pytest-redis<4.1.0 # https://github.com/ClearcodeHQ/pytest-redis/issues/679
+uv