Add chess-style Elo ratings for players

Each player's rating starts at 1500 and updates transactionally with
every finished match: a team's rating is the mean of its two members
and the standard K=32 formula decides the zero-sum delta applied to
both members of a team. Ratings are per game type in a new
player_rating table; match_player records each match's elo_delta.

- GET /api/leaderboard exposes elo and sorts by it
- GET /api/me/matches includes per-player elo deltas
- new GET /api/me/ratings returns the caller's rating per game type
- frontend: Elo column on the leaderboard, per-match delta in the
  history page, current rating in the lobby
- python -m tavolo.backfill_elo recomputes all ratings from the
  recorded match history (one-off backfill for existing matches)

deploy/k8s/tavolo.yaml

@@ -71,13 +71,6 @@ data:
   # CORS_ALLOW_CREDENTIALS: "false"
   # CORS_EXPOSE_HEADERS: ""
   # CORS_MAX_AGE: "600"
-  # OpenTelemetry (kaya-otel): traces + metrics via OTLP/HTTP, disabled
-  # unless OTEL_ENABLED is set. Requires the otel extra in the image.
-  # OTEL_ENABLED: "true"
-  # OTEL_SERVICE_NAME: "tavolo"
-  # OTEL_EXPORTER_OTLP_ENDPOINT: "http://otel-collector.observability:4318"
-  # OTEL_EXPORTER_OTLP_HEADERS: "Authorization=Bearer ..."
-  # OTEL_EXCLUDED_PATHS: "/api/health"   # default; paths skipped by tracing
   # OIDC (provider lives in another namespace).
   OIDC_CLIENT_ID: tavolo
   OIDC_POST_LOGIN_REDIRECT: /

docker-compose.yml

@@ -122,13 +122,6 @@ services:
       CORS_ALLOW_CREDENTIALS: ${CORS_ALLOW_CREDENTIALS:-}
       CORS_EXPOSE_HEADERS: ${CORS_EXPOSE_HEADERS:-}
       CORS_MAX_AGE: ${CORS_MAX_AGE:-}
-      # OpenTelemetry (kaya-otel): disabled unless OTEL_ENABLED is set.
-      # Requires the otel extra in the image (see server/pyproject.toml).
-      OTEL_ENABLED: ${OTEL_ENABLED:-}
-      OTEL_SERVICE_NAME: ${OTEL_SERVICE_NAME:-}
-      OTEL_EXPORTER_OTLP_ENDPOINT: ${OTEL_EXPORTER_OTLP_ENDPOINT:-}
-      OTEL_EXPORTER_OTLP_HEADERS: ${OTEL_EXPORTER_OTLP_HEADERS:-}
-      OTEL_EXCLUDED_PATHS: ${OTEL_EXCLUDED_PATHS:-}
     ports:
       - "127.0.0.1:${APP_PORT:-8080}:8080"
 

server/Dockerfile

@@ -48,21 +48,17 @@ RUN --mount=type=cache,target=/var/cache/apk \
 
 WORKDIR /build
 
-
-COPY server/requirements.txt ./
-RUN --mount=type=cache,target=/root/.cache/pip \
-    python3 -m venv /opt/venv \
- && /opt/venv/bin/pip install --upgrade pip \
- && /opt/venv/bin/pip install -r requirements.txt
-
-COPY server/pyproject.toml server/README.md ./
+COPY server/pyproject.toml server/README.md server/requirements.txt ./
 COPY server/src/ ./src/
-RUN --mount=type=cache,target=/root/.cache/pip \
-    /opt/venv/bin/pip install .
 # aerich migration files are a release artifact: the db-migrate compose
 # service runs `aerich upgrade` from this image before the app starts.
 COPY server/migrations/ ./migrations/
 
+RUN --mount=type=cache,target=/root/.cache/pip \
+    python3 -m venv /opt/venv \
+ && /opt/venv/bin/pip install --upgrade pip \
+ && /opt/venv/bin/pip install -r requirements.txt .
+
 # --- Runtime ---------------------------------------------------------------
 FROM alpine:3.24
 

server/README.md

@@ -69,11 +69,6 @@ All configuration comes from environment variables (see `.env.example`):
 | `CORS_ALLOW_CREDENTIALS` | `false` | `1`/`true`/`yes`/`on` allow cookies/credentials on cross-origin requests |
 | `CORS_EXPOSE_HEADERS` | unset | Comma-separated response headers exposed to the browser |
 | `CORS_MAX_AGE` | `600` | Seconds browsers may cache the preflight response |
-| `OTEL_ENABLED` | `false` | `1`/`true`/`yes`/`on` enable OpenTelemetry traces and metrics (requires the `otel` extra, i.e. `pip install tavolo[otel]`) |
-| `OTEL_SERVICE_NAME` | `tavolo` | `service.name` resource attribute of the exported telemetry |
-| `OTEL_EXPORTER_OTLP_ENDPOINT` | unset | Base URL of an OTLP/HTTP collector (e.g. `http://localhost:4318`); unset uses the exporter default |
-| `OTEL_EXPORTER_OTLP_HEADERS` | unset | Comma-separated `key=value` headers sent to the collector (e.g. authentication) |
-| `OTEL_EXCLUDED_PATHS` | `/api/health` | Comma-separated paths excluded from tracing and metrics (exact matches) |
 | `APP_HOST` / `APP_PORT` | `0.0.0.0` / `8080` | Bind address |
 
 ## Logging

server/pyproject.toml

@@ -32,9 +32,6 @@ dev = [
     "mypy",
     "httpx-ws",
 ]
-otel = [
-    "kaya-otel>=0.0.4",
-]
 
 [tool.setuptools.packages.find]
 where = ["src"]

server/requirements.txt

@@ -50,7 +50,7 @@ idna==3.19
     #   httpx
 iso8601==2.1.0
     # via tortoise-orm
-kaya-core==0.0.4
+kaya-core==0.0.3
     # via
     #   kaya-cors
     #   kaya-oidc
@@ -58,20 +58,20 @@ kaya-core==0.0.4
     #   kaya-rsgi
     #   kaya-session
     #   tavolo (pyproject.toml)
-kaya-cors==0.0.4
+kaya-cors==0.0.3
     # via tavolo (pyproject.toml)
-kaya-oidc==0.0.4
+kaya-oidc==0.0.3
     # via tavolo (pyproject.toml)
-kaya-openapi==0.0.4
+kaya-openapi==0.0.3
     # via tavolo (pyproject.toml)
-kaya-rsgi==0.0.4
+kaya-rsgi==0.0.3
     # via tavolo (pyproject.toml)
-kaya-session==0.0.4
+kaya-session==0.0.3
     # via
     #   kaya-oidc
     #   kaya-session-redis
     #   tavolo (pyproject.toml)
-kaya-session-redis==0.0.4
+kaya-session-redis==0.0.3
     # via tavolo (pyproject.toml)
 pwo==0.1.2
     # via

server/src/tavolo/app.py

@@ -12,9 +12,7 @@ Assembles the :class:`~kaya.core.KayaApp` with four mixins:
   ``/api/openapi.json`` and a Swagger UI at ``/api/docs``)
 
 A :class:`~kaya.cors.CorsMixin` is prepended when CORS is configured via the
-``CORS_*`` environment variables (see :mod:`tavolo.config`). A
-:class:`~kaya.otel.OTelMixin` (optional ``otel`` extra) is prepended when
-``OTEL_ENABLED`` is set, adding OpenTelemetry traces and metrics.
+``CORS_*`` environment variables (see :mod:`tavolo.config`).
 
 Live games are kept in :data:`game_store` (Redis when configured, in-memory
 otherwise). Routes and the websocket handlers are registered by importing
@@ -64,36 +62,6 @@ def cors_mixin_from_settings(settings: Settings) -> Optional[CorsMixin]:
     )
 
 
-def otel_mixin_from_settings(settings: Settings) -> Optional[KayaMixin]:
-    """Build a :class:`~kaya.otel.OTelMixin` from the OTEL_* settings.
-
-    Returns ``None`` — telemetry disabled — unless ``OTEL_ENABLED`` is
-    truthy. kaya-otel is an optional dependency (the ``otel`` extra), so it
-    is imported lazily here: default installs and the test suite never need
-    the OpenTelemetry packages.
-    """
-    if not settings.otel_enabled:
-        return None
-    try:
-        from kaya.otel import OTelMixin
-    except ImportError as exc:
-        raise RuntimeError(
-            "OTEL_ENABLED is set but kaya-otel is not installed; "
-            "install tavolo with the 'otel' extra"
-        ) from exc
-    headers = dict(
-        pair.split("=", 1)
-        for pair in (settings.otel_exporter_headers or ())
-        if "=" in pair
-    )
-    return OTelMixin(
-        service_name=settings.otel_service_name,
-        endpoint=settings.otel_exporter_endpoint,
-        headers=headers or None,
-        excluded_paths=settings.otel_excluded_paths,
-    )
-
-
 session_store: SessionStore
 if settings.redis_url is not None:
     # Lazy client: no connection is opened until a session is actually
@@ -137,19 +105,6 @@ tortoise_mixin = TortoiseMixin(
 
 mixins: list[KayaMixin] = [session_mixin, oidc_mixin, tortoise_mixin, openapi_mixin,
                            DeadlineSchedulerMixin(game_store)]
-otel_mixin = otel_mixin_from_settings(settings)
-if otel_mixin is not None:
-    # First in the list: before hooks run in registration order (after hooks
-    # in reverse), so the span covers session loading, OIDC handling and the
-    # handler itself. CORS, when enabled, is still prepended before it so
-    # preflight short-circuits stay untraced.
-    mixins.insert(0, otel_mixin)
-    log.info(
-        "OpenTelemetry enabled: service=%s endpoint=%s",
-        settings.otel_service_name,
-        settings.otel_exporter_endpoint or "(OTLP default)",
-    )
-
 cors_mixin = cors_mixin_from_settings(settings)
 if cors_mixin is not None:
     # First in the list: preflight requests are answered before the session

server/src/tavolo/config.py

@@ -113,16 +113,6 @@ class Settings:
     cors_allow_credentials: bool
     cors_expose_headers: Optional[Tuple[str, ...]]
     cors_max_age: int
-    # OpenTelemetry (kaya-otel's OTelMixin). Disabled unless OTEL_ENABLED is
-    # truthy; the exporter endpoint falls back to the OTLP/HTTP default
-    # (localhost:4318) when OTEL_EXPORTER_OTLP_ENDPOINT is unset.
-    otel_enabled: bool
-    otel_service_name: str
-    otel_exporter_endpoint: Optional[str]
-    otel_exporter_headers: Optional[Tuple[str, ...]]
-    # Paths excluded from tracing and metrics (exact matches). Defaults to
-    # the health endpoint, which k8s probes would otherwise spam.
-    otel_excluded_paths: Tuple[str, ...]
 
     @staticmethod
     def from_env() -> "Settings":
@@ -169,14 +159,6 @@ class Settings:
             cors_allow_credentials=_env_bool("CORS_ALLOW_CREDENTIALS"),
             cors_expose_headers=_env_list("CORS_EXPOSE_HEADERS"),
             cors_max_age=int(_env("CORS_MAX_AGE", "600")),
-            # OpenTelemetry is opt-in: set OTEL_ENABLED=1 to export traces
-            # and metrics via OTLP/HTTP (requires the ``otel`` extra).
-            otel_enabled=_env_bool("OTEL_ENABLED"),
-            otel_service_name=_env("OTEL_SERVICE_NAME", "tavolo"),
-            otel_exporter_endpoint=os.environ.get("OTEL_EXPORTER_OTLP_ENDPOINT") or None,
-            # Comma-separated key=value pairs, e.g. "Authorization=Bearer x".
-            otel_exporter_headers=_env_list("OTEL_EXPORTER_OTLP_HEADERS"),
-            otel_excluded_paths=_env_list("OTEL_EXCLUDED_PATHS") or ("/api/health",),
         )
 
 

server/tests/test_config.py

@@ -130,40 +130,5 @@ class CorsSettingsTests(unittest.TestCase):
         self.assertEqual(3600, settings.cors_max_age)
 
 
-class OTelSettingsTests(unittest.TestCase):
-    def test_otel_disabled_by_default(self):
-        settings = _settings({})
-        self.assertFalse(settings.otel_enabled)
-        self.assertEqual("tavolo", settings.otel_service_name)
-        self.assertIsNone(settings.otel_exporter_endpoint)
-        self.assertIsNone(settings.otel_exporter_headers)
-
-    def test_otel_enabled_parses_boolean(self):
-        for value in ("1", "true", "TRUE", "yes", "on"):
-            self.assertTrue(_settings({"OTEL_ENABLED": value}).otel_enabled)
-        for value in ("0", "false", "no", "off", "anything-else"):
-            self.assertFalse(_settings({"OTEL_ENABLED": value}).otel_enabled)
-
-    def test_otel_settings_are_passed_through(self):
-        settings = _settings({
-            "OTEL_SERVICE_NAME": "cards",
-            "OTEL_EXPORTER_OTLP_ENDPOINT": "http://collector:4318",
-            "OTEL_EXPORTER_OTLP_HEADERS": "Authorization=Bearer t, X-Tenant=one",
-        })
-        self.assertEqual("cards", settings.otel_service_name)
-        self.assertEqual("http://collector:4318", settings.otel_exporter_endpoint)
-        self.assertEqual(
-            ("Authorization=Bearer t", "X-Tenant=one"),
-            settings.otel_exporter_headers,
-        )
-
-    def test_otel_excluded_paths_defaults_to_health_endpoint(self):
-        self.assertEqual(("/api/health",), _settings({}).otel_excluded_paths)
-
-    def test_otel_excluded_paths_parses_comma_separated_list(self):
-        settings = _settings({"OTEL_EXCLUDED_PATHS": "/api/health, /metrics"})
-        self.assertEqual(("/api/health", "/metrics"), settings.otel_excluded_paths)
-
-
 if __name__ == "__main__":
     unittest.main()

server/tests/test_otel.py

@@ -1,88 +0,0 @@
-"""Unit tests for the OpenTelemetry wiring in :mod:`tavolo.app`.
-
-The mixin under test is kaya-otel's :class:`~kaya.otel.OTelMixin`, an
-optional dependency (the ``otel`` extra); these tests only verify that
-:func:`tavolo.app.otel_mixin_from_settings` maps the ``OTEL_*`` settings
-onto mixin construction. The ``kaya.otel`` module is stubbed in
-``sys.modules`` so the suite does not need the extra installed.
-"""
-from __future__ import annotations
-
-import os
-import sys
-import types
-import unittest
-from unittest.mock import patch
-
-from tavolo.app import otel_mixin_from_settings
-from tavolo.config import Settings
-
-
-def _settings(env: dict) -> Settings:
-    with patch.dict(os.environ, env, clear=True):
-        return Settings.from_env()
-
-
-class _StubOTelMixin:
-    def __init__(self, **kwargs):
-        self.kwargs = kwargs
-
-
-def _stub_kaya_otel():
-    """Install a fake ``kaya.otel`` module and return it."""
-    module = types.ModuleType("kaya.otel")
-    module.OTelMixin = _StubOTelMixin  # type: ignore[attr-defined]
-    return patch.dict(sys.modules, {"kaya.otel": module})
-
-
-class OTelMixinFromSettingsTests(unittest.TestCase):
-    def test_disabled_by_default(self):
-        self.assertIsNone(otel_mixin_from_settings(_settings({})))
-
-    def test_enabled_by_otel_enabled(self):
-        with _stub_kaya_otel():
-            mixin = otel_mixin_from_settings(_settings({"OTEL_ENABLED": "1"}))
-        self.assertIsNotNone(mixin)
-
-    def test_settings_are_passed_through(self):
-        with _stub_kaya_otel():
-            mixin = otel_mixin_from_settings(_settings({
-                "OTEL_ENABLED": "true",
-                "OTEL_SERVICE_NAME": "cards",
-                "OTEL_EXPORTER_OTLP_ENDPOINT": "http://collector:4318",
-                "OTEL_EXPORTER_OTLP_HEADERS": "Authorization=Bearer t, X-Tenant=one",
-            }))
-        assert isinstance(mixin, _StubOTelMixin)
-        self.assertEqual({
-            "service_name": "cards",
-            "endpoint": "http://collector:4318",
-            "headers": {"Authorization": "Bearer t", "X-Tenant": "one"},
-            "excluded_paths": ("/api/health",),
-        }, mixin.kwargs)
-
-    def test_defaults_when_only_enabled(self):
-        with _stub_kaya_otel():
-            mixin = otel_mixin_from_settings(_settings({"OTEL_ENABLED": "on"}))
-        assert isinstance(mixin, _StubOTelMixin)
-        self.assertEqual("tavolo", mixin.kwargs["service_name"])
-        self.assertIsNone(mixin.kwargs["endpoint"])
-        self.assertIsNone(mixin.kwargs["headers"])
-        self.assertEqual(("/api/health",), mixin.kwargs["excluded_paths"])
-
-    def test_excluded_paths_are_passed_through(self):
-        with _stub_kaya_otel():
-            mixin = otel_mixin_from_settings(_settings({
-                "OTEL_ENABLED": "1",
-                "OTEL_EXCLUDED_PATHS": "/api/health,/metrics",
-            }))
-        assert isinstance(mixin, _StubOTelMixin)
-        self.assertEqual(("/api/health", "/metrics"), mixin.kwargs["excluded_paths"])
-
-    def test_missing_extra_raises_runtime_error(self):
-        with patch.dict(sys.modules, {"kaya.otel": None}):
-            with self.assertRaises(RuntimeError):
-                otel_mixin_from_settings(_settings({"OTEL_ENABLED": "1"}))
-
-
-if __name__ == "__main__":
-    unittest.main()