Add CORS handling, and load settings from .env

app/main.py

@@ -1,19 +1,40 @@
 '''
 Simple Geolocation with FastAPI
 '''
+import os
 from ipaddress import IPv4Address, IPv4Network, IPv6Address, IPv6Network
 from typing import Annotated, Optional, Union
 
 import geoip2.database
-from geoip2.errors import AddressNotFoundError
-from fastapi import FastAPI, Path, Body, Request, Response, status
+from dotenv import load_dotenv
+from fastapi import Body, FastAPI, Path, Request, Response, status
+from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import RedirectResponse
+from geoip2.errors import AddressNotFoundError
 from pydantic import BaseModel
 
+# Load environment variables
+load_dotenv()
+
 app = FastAPI()
 
-GEOLITE2_ASN_DB = '/usr/local/share/GeoIP/GeoLite2-ASN.mmdb'
-GEOLITE2_CITY_DB = '/usr/local/share/GeoIP/GeoLite2-City.mmdb'
+# Configure CORS from environment variables
+cors_origins = os.getenv('CORS_ALLOW_ORIGINS', 'http://localhost')
+allow_origins = [origin.strip() for origin in cors_origins.split(',')
+                 if origin.strip()]
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=allow_origins,
+    allow_credentials=True,
+    allow_methods=["GET", "POST", "PUT", "DELETE", "OPTIONS"],
+    allow_headers=["*"],
+)
+
+GEOLITE2_ASN_DB = os.getenv('GEOLITE2_ASN_DB',
+                            '/usr/local/share/GeoIP/GeoLite2-ASN.mmdb')
+GEOLITE2_CITY_DB = os.getenv('GEOLITE2_CITY_DB',
+                             '/usr/local/share/GeoIP/GeoLite2-City.mmdb')
 
 
 class IPAddressParam(BaseModel):