Paramless RPC client proxy

rpc_proxy.py

#!/usr/bin/env python3

import http.server
import socketserver
import json
import urllib.request
import os
from datetime import datetime

def load_env():
    if os.path.exists('.env'):
        with open('.env', 'r') as f:
            for line in f:
                line = line.strip()
                if line and not line.startswith('#') and '=' in line:
                    key, value = line.split('=', 1)
                    os.environ[key.strip()] = value.strip()

load_env()
RPC_URL = os.getenv('RPC_URL')

class ThreadedHTTPServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
    allow_reuse_address = True

class AsyncRPCProxyHandler(http.server.BaseHTTPRequestHandler):
    
    def do_POST(self):
        content_length = int(self.headers.get('Content-Length', 0))
        if content_length == 0:
            self.send_error(400, "Empty request body")
            return
            
        body = self.rfile.read(content_length)
        
        try:
            request_data = json.loads(body.decode('utf-8'))
        except (json.JSONDecodeError, UnicodeDecodeError):
            self.send_error(400, "Invalid JSON")
            return
        
        timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
        print(f"[{timestamp}]: {request_data.get('method', 'unknown')} from {self.client_address[0]}")
        
        if 'params' not in request_data:
            request_data['params'] = []
        
        try:
            if not RPC_URL:
                self.send_error(500, "RPC_URL not configured")
                return
            
            req = urllib.request.Request(
                RPC_URL,
                data=json.dumps(request_data).encode('utf-8'),
                headers={'Content-Type': 'application/json'}
            )
            
            with urllib.request.urlopen(req) as response:
                response_data = response.read()
                
            self.send_response(200)
            self.send_header('Content-Type', 'application/json')
            self.send_header('Access-Control-Allow-Origin', '*')
            self.send_header('Access-Control-Allow-Methods', 'POST, OPTIONS')
            self.send_header('Access-Control-Allow-Headers', 'Content-Type')
            self.end_headers()
            
            self.wfile.write(response_data)
            
        except Exception as e:
            print(f"Error proxying request: {e}")
            self.send_error(502, "Bad Gateway")
    
    def do_OPTIONS(self):
        self.send_response(200)
        self.send_header('Access-Control-Allow-Origin', '*')
        self.send_header('Access-Control-Allow-Methods', 'POST, OPTIONS')
        self.send_header('Access-Control-Allow-Headers', 'Content-Type')
        self.end_headers()
    

def main():
    if not RPC_URL:
        print("Error: RPC_URL not found in .env file")
        return
    
    PORT = 1234
    HOST = "localhost"
    
    print(f"Threaded RPC Proxy started on {HOST}:{PORT}")
    print(f"Proxying to: {RPC_URL}")
    
    try:
        with ThreadedHTTPServer((HOST, PORT), AsyncRPCProxyHandler) as httpd:
            httpd.serve_forever()
    except KeyboardInterrupt:
        print("\nServer stopped")
    except Exception as e:
        print(f"Server error: {e}")

if __name__ == "__main__":
    main()