Add playground backend and proxy

playground/backend_manager/app/main.py

@@ -0,0 +1,84 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from contextlib import asynccontextmanager
+import logging
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import FileResponse
+from fastapi.staticfiles import StaticFiles
+from app.config import settings
+from app.routers import auth_router, health_router, session_router
+from app.services.session_manager import session_manager
+
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
+)
+logger = logging.getLogger("artemis.backend")
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """Application startup and shutdown hooks."""
+    logger.info(f"Starting {settings.APP_NAME} in [{settings.APP_ENV}] mode...")
+    # Start the background session expiration watchdog
+    session_manager.start_background_reaper()
+    yield
+    logger.info(f"Shutting down {settings.APP_NAME}...")
+
+
+app = FastAPI(
+    title=settings.APP_NAME,
+    description="Backend Management & Orchestration Service for Artemis on Container OS",
+    version="1.0.0",
+    lifespan=lifespan,
+)
+
+# Enable CORS for local development and Nginx proxying
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Register API Routers
+app.include_router(health_router.router)
+app.include_router(auth_router.router)
+app.include_router(session_router.router)
+
+# Mount static asset directory
+if settings.STATIC_DIR.exists():
+    app.mount("/static", StaticFiles(directory=str(settings.STATIC_DIR)), name="static")
+
+
+@app.get("/", include_in_schema=False)
+async def serve_spa_root():
+    """Serve the root Single Page Application."""
+    index_file = settings.STATIC_DIR / "index.html"
+    if index_file.exists():
+        return FileResponse(str(index_file))
+    return {"message": f"{settings.APP_NAME} is active. API documentation at /docs"}
+
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(
+        "app.main:app",
+        host=settings.HOST,
+        port=settings.PORT,
+        reload=settings.DEBUG,
+    )