app.py

from flask import Flask, request, Response, stream_with_context
import requests
import os
import json

app = Flask(__name__)

# Target API base URL from environment variable
TARGET_API = os.getenv("TARGET_API", "https://huggingface.co")

# Path mappings from environment variable
# Expected format: {"path1": "mapped_path1", "path2": "mapped_path2"}
def get_path_mappings():
    mappings_str = os.getenv("PATH_MAPPINGS", '{"/": "/"}')
    try:
        return json.loads(mappings_str)
    except json.JSONDecodeError:
        # Fallback to default mappings if JSON is invalid
        return {
            "/": "/",
        }

PATH_MAPPINGS = get_path_mappings()


@app.route('/<path:path>', methods=['GET', 'POST', 'PUT', 'DELETE', 'PATCH'])
def proxy(path):
    # Construct the full path
    full_path = f"/{path}"

    # Apply path mapping if matches
    for original_path, new_path in PATH_MAPPINGS.items():
        if full_path.startswith(original_path):
            full_path = full_path.replace(original_path, new_path, 1)
            break

    # Construct target URL
    target_url = f"{TARGET_API}{full_path}"

    # Forward the request to the target API
    headers = {key: value for key, value in request.headers if key != 'Host'}

    # Handle streaming response
    if request.method == 'POST':
        response = requests.post(
            target_url,
            headers=headers,
            json=request.get_json(silent=True),
            params=request.args,
            stream=True
        )
    elif request.method == 'GET':
        response = requests.get(
            target_url,
            headers=headers,
            params=request.args,
            stream=True
        )
    elif request.method == 'PUT':
        response = requests.put(
            target_url,
            headers=headers,
            json=request.get_json(silent=True),
            params=request.args,
            stream=True
        )
    elif request.method == 'DELETE':
        response = requests.delete(
            target_url,
            headers=headers,
            params=request.args,
            stream=True
        )
    elif request.method == 'PATCH':
        response = requests.patch(
            target_url,
            headers=headers,
            json=request.get_json(silent=True),
            params=request.args,
            stream=True
        )

    # Create a response with the same status code, headers, and streaming content
    def generate():
        for chunk in response.iter_content(chunk_size=8192):
            yield chunk

    # Create flask response
    proxy_response = Response(
        stream_with_context(generate()),
        status=response.status_code
    )

    # Forward response headers
    for key, value in response.headers.items():
        if key.lower() not in ('content-length', 'transfer-encoding', 'connection'):
            proxy_response.headers[key] = value

    return proxy_response


@app.route('/', methods=['GET'])
def index():
    return "service running."


if __name__ == '__main__':
    app.run(host='0.0.0.0', port=7860, debug=False)