背景
前端直接调用paddlex serve服务时，由于前端会发送OPTIONS请求，paddlex默认会拒绝跨域请求。
另外由于前端限制，需要把Response中errorCode、errorMsg替换成code、message。
方案
Nginx
通过 Nginx 的 sub_filter 或 OpenResty 的 Lua 脚本修改 JSON 键名（适用于简单替换）。
Nginx是替换，存在把正常的内容替换的情况，不推荐。
Nginx 配置示例：
server {listen 80;server_name your_domain.com;location /predict {proxy_pass http://localhost:8000; # PaddleX 服务地址sub_filter '"errorCode":' '"code":'; # 替换字段sub_filter '"errorMsg":' '"message":';sub_filter '"result":' '"data":';sub_filter_once off;sub_filter_types application/json;}
}
修改配置后重载 Nginx：
sudo nginx -t && sudo systemctl reload nginx
uvicorn（Python代理）
Uvicorn 作为一款基于异步 I/O 的 ASGI 服务器，在高并发场景下表现优异，但其性能也受到配置、应用逻辑、硬件资源等因素影响。
1.编写代理
新建proxy.py文件：
from fastapi import FastAPI, Request, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
import requests
import logging# 配置日志
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)app = FastAPI()# 跨域配置
app.add_middleware(CORSMiddleware,allow_origins=["*"],allow_credentials=True,allow_methods=["*"],allow_headers=["*"],
)PADDLEX_SERVER = "http://localhost:8080"@app.post("/ocr")
async def predict(request: Request):try:# 1. 获取客户端请求体client_json = await request.json()# 2. 转发请求到 PaddleX 服务response = requests.post(f"{PADDLEX_SERVER}/ocr",json=client_json,timeout=30 # 添加超时控制)response.raise_for_status() # 自动抛出 HTTP 错误# 3. 处理原始响应数据try:response_data = response.json()except requests.exceptions.JSONDecodeError:logger.error("PaddleX 返回了非 JSON 响应")raise HTTPException(502, "后端服务响应格式错误")# 4. 字段替换逻辑if "errorCode" in response_data:response_data["code"] = response_data.pop("errorCode")if "errorMsg" in response_data:response_data["message"] = response_data.pop("errorMsg")if "result" in response_data:response_data["data"] = response_data.pop("result")if "code" in response_data and response_data["code"] == 0:response_data["code"] = 200# 5. 返回修改后的响应（移除 Content-Length 头）headers = dict(response.headers)headers.pop("Content-Length", None) # 删除原始 Content-Lengthheaders.pop("content-length", None) # 小写 key 兼容headers.pop("server", None) # 小写 key 兼容headers.pop("date", None) # 小写 key 兼容return JSONResponse(content=response_data,status_code=response.status_code,headers=headers)except requests.exceptions.RequestException as e:logger.error(f"请求后端服务失败: {str(e)}")raise HTTPException(504, f"后端服务通信失败: {str(e)}")except Exception as e:logger.error(f"未知错误: {str(e)}")raise HTTPException(500, "服务器内部错误")if __name__ == "__main__":import uvicornuvicorn.run(app, host="0.0.0.0", port=8090)
2.启动代理
nohup python paddleImageOcrProxy.py > paddleImageOcrProxy.log 2>&1 &
查看日志：
$ tail -fn 200 paddleImageOcrProxy.log
INFO: Started server process [18566]
INFO: Waiting for application startup.
INFO: Application startup complete.
INFO: Uvicorn running on http://0.0.0.0:8090 (Press CTRL+C to quit)
INFO: 10.90.201.61:10346 - "POST /ocr HTTP/1.1" 200 OK
INFO: 10.90.201.61:10357 - "POST /ocr HTTP/1.1" 200 OK
INFO: 10.90.201.61:10357 - "POST /ocr HTTP/1.1" 200 OK
INFO: 10.90.200.182:52519 - "OPTIONS /ocr HTTP/1.1" 200 OK
INFO: 10.90.200.182:52519 - "POST /ocr HTTP/1.1" 200 OK