Support multiple OIDC providers

kaya-oidc 0.0.6 can run several providers in one app (OIDCProviders),
each with its own login route and namespaced session state. Adopt it:
providers are configured in indexed, contiguous OIDC_<n>_* blocks
(0-based) with OIDC_<n>_PROVIDER naming the provider in its login URL
and session keys. The old unindexed OIDC_ISSUER/OIDC_CLIENT_ID/... names
are no longer read; startup fails with a rename hint when they are set.
With no OIDC variables at all, the single dev mock provider named
"default" is used, as before.

The platform now authenticates through OIDCProviders: auth.current_user
returns the session's user (sessions stay single-identity, so at most one
provider is logged in) and require_auth/route handlers use it, while the
websocket path keeps scanning for any provider's user. New routes expose
the configuration to the SPA and keep old links working: GET
/api/auth/providers lists the login URLs, GET /auth/login redirects to
the first provider and GET /auth/logout to whichever provider the
session is logged in with. The lobby renders one login button per
provider from that endpoint.

Update the env examples, compose and k8s manifests to the indexed scheme,
document the multiple-provider setup and the migration, and cover it with
config, auth and route tests.

server/packages/tavolo-platform/pyproject.toml

@@ -11,7 +11,7 @@ requires-python = ">=3.10"
 dependencies = [
     "kaya-core>=0.0.6",
     "kaya-session",
-    "kaya-oidc",
+    "kaya-oidc>=0.0.6",
     "kaya-openapi",
     "tortoise-orm",
     "redis",

server/packages/tavolo-platform/src/tavolo/platform/auth.py

@@ -9,7 +9,7 @@ from __future__ import annotations
 from typing import Any, Callable, Mapping, Optional
 
 from kaya.core import HttpContext, WebSocket
-from kaya.oidc import OIDCMixin, OIDCUser
+from kaya.oidc import OIDCProviders, OIDCUser
 from kaya.session import Session
 
 # kaya-oidc namespaces its session state per provider as
@@ -55,7 +55,16 @@ def display_name(user: OIDCUser) -> str:
     return user.sub
 
 
-def require_auth(oidc: OIDCMixin) -> Callable[[Callable[..., Any]], Callable[..., Any]]:
+def current_user(oidc: OIDCProviders, ctx: HttpContext) -> Optional[OIDCUser]:
+    """Return the authenticated user of an HTTP request, if any.
+
+    Sessions are single-identity by default, so at most one provider has
+    a user; if several do, the first configured provider wins.
+    """
+    return next(iter(oidc.get_users(ctx).values()), None)
+
+
+def require_auth(oidc: OIDCProviders) -> Callable[[Callable[..., Any]], Callable[..., Any]]:
     """Build a decorator gating a handler on being authenticated.
 
     Responds ``401`` with a JSON error envelope when unauthenticated —
@@ -65,7 +74,7 @@ def require_auth(oidc: OIDCMixin) -> Callable[[Callable[..., Any]], Callable[...
 
     def decorator(handler: Callable[..., Any]) -> Callable[..., Any]:
         async def guarded(ctx: HttpContext, *args: Any, **kwargs: Any) -> None:
-            if oidc.get_user(ctx) is None:
+            if current_user(oidc, ctx) is None:
                 await ctx.send_bytes(
                     401,
                     b'{"error":"unauthenticated"}',

server/packages/tavolo-platform/src/tavolo/platform/mixin.py

@@ -2,7 +2,7 @@
 
 ``Platform`` bundles the collaborators every platform endpoint needs —
 the game registry, the live-game store, the deadline scheduler and the
-OIDC mixin used for authentication — so route and websocket modules
+OIDC providers used for authentication — so route and websocket modules
 never reach for module-global state. :class:`PlatformMixin` is a plain
 :class:`~kaya.core.KayaMixin`: applying it registers the lobby, stats
 and health HTTP routes plus the live-play websocket endpoint, and the
@@ -14,7 +14,7 @@ from __future__ import annotations
 from dataclasses import dataclass
 
 from kaya.core import KayaApp, KayaMixin
-from kaya.oidc import OIDCMixin
+from kaya.oidc import OIDCProviders
 
 from .deadlines import DeadlineScheduler
 from .registry import GameRegistry
@@ -28,7 +28,7 @@ class Platform:
     registry: GameRegistry
     game_store: GameStore
     scheduler: DeadlineScheduler
-    oidc: OIDCMixin
+    oidc: OIDCProviders
 
 
 class PlatformMixin(KayaMixin):
@@ -41,9 +41,10 @@ class PlatformMixin(KayaMixin):
         # Imported here so module import order stays acyclic: the route
         # modules reference Platform only for typing.
         from . import ws
-        from .routes import games, health, me, stats
+        from .routes import auth, games, health, me, stats
 
         health.register(app, self.platform)
+        auth.register(app, self.platform)
         me.register(app, self.platform)
         games.register(app, self.platform)
         stats.register(app, self.platform)

server/packages/tavolo-platform/src/tavolo/platform/routes/auth.py

@@ -0,0 +1,62 @@
+"""Authentication plumbing for the single-page app.
+
+kaya-oidc registers one login/callback/logout route per provider
+(``/auth/<provider>/...``); this module adds the provider-agnostic
+pieces:
+
+* ``GET /api/auth/providers`` lists the configured providers with their
+  login URLs, so the SPA can offer a choice without hardcoding names;
+* ``GET /auth/login`` redirects to the first configured provider;
+* ``GET /auth/logout`` redirects to the provider this session is logged
+  in with (or the SPA root when not logged in), so the UI can keep a
+  single logout link.
+"""
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from kaya.core import HttpContext, KayaApp
+from kaya.openapi import operation
+
+from ..http import send_json
+
+if TYPE_CHECKING:
+    from ..mixin import Platform
+
+
+def _login_url(platform: "Platform", provider: str) -> str:
+    return f"{platform.oidc.base_path}/{provider}/login"
+
+
+def register(app: KayaApp, platform: "Platform") -> None:
+    providers = list(platform.oidc.providers)
+
+    @app.GET("/api/auth/providers")
+    @operation(summary="Configured login providers",
+               description="Names and login URLs of the configured OIDC "
+                           "providers, in configuration order.",
+               tags=["auth"],
+               responses={200: {"description": "The configured providers"}})
+    async def auth_providers(ctx: HttpContext) -> None:
+        await send_json(
+            ctx,
+            200,
+            {
+                "providers": [
+                    {"name": name, "login_url": _login_url(platform, name)}
+                    for name in providers
+                ]
+            },
+        )
+
+    @app.GET("/auth/login")
+    async def login(ctx: HttpContext) -> None:
+        await ctx.send_empty(302, {"Location": _login_url(platform, providers[0])})
+
+    @app.GET("/auth/logout")
+    async def logout(ctx: HttpContext) -> None:
+        logged_in = platform.oidc.logged_in_providers(ctx)
+        location = (
+            f"{platform.oidc.base_path}/{logged_in[0]}/logout" if logged_in else "/"
+        )
+        await ctx.send_empty(302, {"Location": location})

server/packages/tavolo-platform/src/tavolo/platform/routes/games.py

@@ -21,7 +21,7 @@ from typing import TYPE_CHECKING, Any, Dict
 from kaya.core import HttpContext, KayaApp
 from kaya.openapi import operation
 
-from ..auth import display_name, require_auth
+from ..auth import current_user, display_name, require_auth
 from ..engine import GameSession, Seat
 from ..errors import GameError
 from ..http import (
@@ -183,7 +183,7 @@ def register(app: KayaApp, platform: "Platform") -> None:
             await send_error(ctx, 400, "options must be an object")
             return
 
-        user = platform.oidc.get_user(ctx)
+        user = current_user(platform.oidc, ctx)
         assert user is not None  # enforced by @require_auth
         session = GameSession(
             id=str(uuid.uuid4()),
@@ -244,7 +244,7 @@ def register(app: KayaApp, platform: "Platform") -> None:
             await send_error(ctx, 400, "code is required")
             return
 
-        user = platform.oidc.get_user(ctx)
+        user = current_user(platform.oidc, ctx)
         assert user is not None
         existing = await platform.game_store.find_by_code(code)
         if existing is None:
@@ -325,7 +325,7 @@ def register(app: KayaApp, platform: "Platform") -> None:
         if session is None:
             await send_error(ctx, 404, "game not found")
             return
-        user = platform.oidc.get_user(ctx)
+        user = current_user(platform.oidc, ctx)
         assert user is not None
         if not session.seated(user.sub):
             await send_error(ctx, 403, "forbidden")

server/packages/tavolo-platform/src/tavolo/platform/routes/me.py

@@ -6,7 +6,7 @@ from typing import TYPE_CHECKING
 from kaya.core import HttpContext, KayaApp
 from kaya.openapi import operation
 
-from ..auth import display_name, require_auth
+from ..auth import current_user, display_name, require_auth
 from ..http import send_json
 
 if TYPE_CHECKING:
@@ -25,6 +25,6 @@ def register(app: KayaApp, platform: "Platform") -> None:
                })
     @require_auth(platform.oidc)
     async def me(ctx: HttpContext) -> None:
-        user = platform.oidc.get_user(ctx)
+        user = current_user(platform.oidc, ctx)
         assert user is not None  # enforced by @require_auth
         await send_json(ctx, 200, {"sub": user.sub, "name": display_name(user)})

server/packages/tavolo-platform/src/tavolo/platform/routes/stats.py

@@ -15,7 +15,7 @@ from uuid import UUID
 from kaya.core import HttpContext, KayaApp
 from kaya.openapi import operation
 
-from ..auth import require_auth
+from ..auth import current_user, require_auth
 from ..elo import INITIAL_RATING
 from ..http import extract_query_params, send_error, send_json
 from ..models import Match, MatchPlayer, PlayerRating
@@ -104,7 +104,7 @@ def register(app: KayaApp, platform: "Platform") -> None:
         if error is not None:
             await send_error(ctx, 400, error)
             return
-        user = platform.oidc.get_user(ctx)
+        user = current_user(platform.oidc, ctx)
         assert user is not None
         queryset = Match.filter(players__user_sub=user.sub).distinct()
         if game_type is not None:
@@ -193,7 +193,7 @@ def register(app: KayaApp, platform: "Platform") -> None:
                })
     @require_auth(platform.oidc)
     async def my_ratings(ctx: HttpContext) -> None:
-        user = platform.oidc.get_user(ctx)
+        user = current_user(platform.oidc, ctx)
         assert user is not None
         rows = await PlayerRating.filter(user_sub=user.sub).order_by("game_type")
         await send_json(ctx, 200, {

server/packages/tavolo-platform/tests/helpers.py

@@ -8,7 +8,7 @@ without importing any real game. Its rules: the first player to reach
 ``target`` plays wins the match.
 
 :func:`make_platform` builds a throwaway :class:`~kaya.core.KayaApp`
-wired with in-memory stores, a dummy OIDC mixin (patched per test) and
+wired with in-memory stores, dummy OIDC providers (patched per test) and
 a sqlite :class:`~tavolo.platform.tortoise_mixin.TortoiseMixin`, so
 tests construct their own app instead of importing a global one.
 """
@@ -22,7 +22,7 @@ from functools import wraps
 from typing import Any, Callable, Coroutine, Dict, Iterator, List, Mapping, Optional, Sequence, Tuple
 
 from kaya.core import KayaApp
-from kaya.oidc import OIDCConfig, OIDCMixin, OIDCUser
+from kaya.oidc import OIDCConfig, OIDCProviders, OIDCUser
 from kaya.openapi import OpenAPIMixin
 from kaya.session import InMemorySessionStore, SessionMixin
 
@@ -221,20 +221,25 @@ class DummyEngine(GameEngine):
 def make_platform(
     engines: Sequence[GameEngine] = (DummyEngine(),),
     heartbeat_ms: int = 50,
+    oidc_providers: Sequence[str] = ("default",),
 ) -> Tuple[KayaApp, Platform, TortoiseMixin]:
     """Build a throwaway app + platform wired with in-memory stores."""
     registry = GameRegistry(engines)
     game_store = InMemoryGameStore(registry)
     session_mixin = SessionMixin(InMemorySessionStore())
-    oidc_mixin = OIDCMixin(
-        OIDCConfig(
-            issuer="http://localhost:8180/tavolo",
-            client_id="tavolo",
-            client_secret=None,
-            redirect_uri="http://localhost:8080/auth/callback",
-            post_login_redirect="/",
-            post_logout_redirect="/",
-        ),
+    oidc = OIDCProviders(
+        [
+            OIDCConfig(
+                provider=name,
+                issuer=f"http://localhost:8180/{name}",
+                client_id="tavolo",
+                client_secret=None,
+                redirect_uri=f"http://localhost:8080/auth/{name}/callback",
+                post_login_redirect="/",
+                post_logout_redirect="/",
+            )
+            for name in oidc_providers
+        ],
         session=session_mixin,
     )
     tortoise_mixin = TortoiseMixin(
@@ -259,12 +264,12 @@ def make_platform(
         registry=registry,
         game_store=game_store,
         scheduler=scheduler,
-        oidc=oidc_mixin,
+        oidc=oidc,
     )
     app = KayaApp(
         mixins=[
             session_mixin,
-            oidc_mixin,
+            oidc,
             tortoise_mixin,
             openapi_mixin,
             PlatformMixin(platform),
@@ -320,10 +325,12 @@ def make_user(sub: str, name: Optional[str] = None) -> OIDCUser:
 
 
 @contextlib.contextmanager
-def oidc_user(oidc: OIDCMixin, sub: str, name: Optional[str] = None) -> Iterator[OIDCUser]:
-    """Context manager: patch ``oidc.get_user`` to return this user."""
+def oidc_user(oidc: OIDCProviders, sub: str, name: Optional[str] = None) -> Iterator[OIDCUser]:
+    """Context manager: make ``oidc.get_users`` return this user for the
+    first configured provider."""
     user = make_user(sub, name)
-    patcher = _mock.patch.object(oidc, "get_user", return_value=user)
+    provider = next(iter(oidc.providers))
+    patcher = _mock.patch.object(oidc, "get_users", return_value={provider: user})
     patcher.start()
     try:
         yield user

server/packages/tavolo-platform/tests/test_auth.py

@@ -1,9 +1,9 @@
-"""Tests for the auth helpers' OIDC user lookup.
+"""Tests for the auth helpers' OIDC user lookup and gating.
 
 kaya-oidc (0.0.6) namespaces session state per provider as
-``oidc:{provider}:user``; these tests pin that contract so a kaya
-upgrade that changes it again cannot silently break websocket
-authentication or span tagging.
+``oidc:{provider}:user`` and tavolo wires an :class:`OIDCProviders`; these
+tests pin both contracts so a kaya upgrade or a provider change cannot
+silently break HTTP or websocket authentication.
 """
 from __future__ import annotations
 
@@ -11,9 +11,31 @@ import unittest
 from types import SimpleNamespace
 from typing import Any
 
-from kaya.session import Session
+from kaya.oidc import OIDCConfig, OIDCProviders
+from kaya.session import InMemorySessionStore, Session, SessionMixin
 
-from tavolo.platform.auth import get_ws_user, session_user
+from helpers import async_test
+from tavolo.platform.auth import current_user, get_ws_user, require_auth, session_user
+
+
+def _providers(*names: str) -> OIDCProviders:
+    session = SessionMixin(InMemorySessionStore())
+    return OIDCProviders(
+        [
+            OIDCConfig(
+                provider=name,
+                issuer=f"http://localhost:8180/{name}",
+                client_id="tavolo",
+                redirect_uri=f"http://localhost:8080/auth/{name}/callback",
+            )
+            for name in names
+        ],
+        session=session,
+    )
+
+
+def _ctx(data: Any) -> Any:
+    return SimpleNamespace(session=Session("sid", data))
 
 
 def _ws(session: Any) -> Any:
@@ -63,3 +85,68 @@ class GetWsUserTest(unittest.TestCase):
 
     def test_missing_session_returns_none(self) -> None:
         self.assertIsNone(get_ws_user(SimpleNamespace()))
+
+
+class CurrentUserTest(unittest.TestCase):
+    def test_anonymous_session_has_no_user(self) -> None:
+        self.assertIsNone(current_user(_providers("default"), _ctx({})))
+
+    def test_returns_the_authenticated_provider_user(self) -> None:
+        user = current_user(
+            _providers("default", "google"),
+            _ctx({"oidc:google:user": {"sub": "alice"}}),
+        )
+        assert user is not None
+        self.assertEqual("alice", user.sub)
+
+    def test_first_configured_provider_wins(self) -> None:
+        # Single-identity sessions never hold two users; this only pins the
+        # tie-break should they ever coexist.
+        user = current_user(
+            _providers("default", "google"),
+            _ctx(
+                {
+                    "oidc:default:user": {"sub": "alice"},
+                    "oidc:google:user": {"sub": "bob"},
+                }
+            ),
+        )
+        assert user is not None
+        self.assertEqual("alice", user.sub)
+
+
+class RequireAuthTest(unittest.TestCase):
+    @async_test
+    async def test_rejects_anonymous_requests(self) -> None:
+        oidc = _providers("default")
+        ctx = _ctx({})
+        sent = {}
+
+        async def send_bytes(*args: Any) -> None:
+            sent["status"] = args[0]
+
+        ctx.send_bytes = send_bytes
+        handled = []
+
+        @require_auth(oidc)
+        async def handler(_ctx: Any) -> None:
+            handled.append(True)
+
+        await handler(ctx)
+        self.assertEqual(401, sent["status"])
+        self.assertEqual([], handled)
+
+    @async_test
+    async def test_allows_authenticated_requests(self) -> None:
+        oidc = _providers("default")
+        ctx = _ctx({"oidc:default:user": {"sub": "alice"}})
+        handled = []
+
+        @require_auth(oidc)
+        async def handler(request_ctx: Any) -> None:
+            user = current_user(oidc, request_ctx)
+            assert user is not None
+            handled.append(user.sub)
+
+        await handler(ctx)
+        self.assertEqual(["alice"], handled)

server/packages/tavolo-platform/tests/test_routes_auth.py

@@ -0,0 +1,67 @@
+"""Tests for the provider-agnostic auth routes.
+
+``GET /api/auth/providers`` feeds the SPA's login buttons; ``/auth/login``
+and ``/auth/logout`` are the generic aliases that redirect to the right
+per-provider kaya route.
+"""
+from __future__ import annotations
+
+import unittest
+from unittest import mock
+
+from httpx import ASGITransport, AsyncClient
+
+from helpers import async_test, make_platform
+
+
+class AuthProvidersRouteTest(unittest.TestCase):
+    @async_test
+    async def test_lists_providers_in_configuration_order(self) -> None:
+        app, _platform, _tortoise = make_platform(oidc_providers=("default", "google"))
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
+            response = await client.get("/api/auth/providers")
+        self.assertEqual(200, response.status_code)
+        self.assertEqual(
+            {
+                "providers": [
+                    {"name": "default", "login_url": "/auth/default/login"},
+                    {"name": "google", "login_url": "/auth/google/login"},
+                ]
+            },
+            response.json(),
+        )
+
+
+class GenericAuthRedirectTest(unittest.TestCase):
+    @async_test
+    async def test_login_redirects_to_the_first_provider(self) -> None:
+        app, _platform, _tortoise = make_platform(oidc_providers=("google", "github"))
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
+            response = await client.get("/auth/login", follow_redirects=False)
+        self.assertEqual(302, response.status_code)
+        self.assertEqual("/auth/google/login", response.headers["location"])
+
+    @async_test
+    async def test_logout_redirects_to_the_logged_in_provider(self) -> None:
+        app, platform, _tortoise = make_platform()
+        with mock.patch.object(
+            platform.oidc, "logged_in_providers", return_value=["default"]
+        ):
+            transport = ASGITransport(app=app)
+            async with AsyncClient(
+                transport=transport, base_url="http://127.0.0.1"
+            ) as client:
+                response = await client.get("/auth/logout", follow_redirects=False)
+        self.assertEqual(302, response.status_code)
+        self.assertEqual("/auth/default/logout", response.headers["location"])
+
+    @async_test
+    async def test_logout_without_a_session_redirects_home(self) -> None:
+        app, _platform, _tortoise = make_platform()
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
+            response = await client.get("/auth/logout", follow_redirects=False)
+        self.assertEqual(302, response.status_code)
+        self.assertEqual("/", response.headers["location"])