Flask + Nginx + Docker-compose 遇到 502 Bad Gateway 问题

请教一下，我用 docker-compose 部署 Flask + Nginx + Docker-compose + gunicorn 应用，本地访问 0.0.0.0:5000 可以访问，访问 0.0.0.0:80 显示 502 bad gate，但 0.0.0.0:80/static/… 静态文件能成功访问，不知道是配置文件哪个地方配错，有没有什么建议？非常感谢

docker-compose.yml

version: '3' services: webapp: build: . # command: bash ./start_server.sh # env_file: .env volumes: - ./webapp:/iodock/ ports: - "5000:5000" # web 容器内的 5000 端口映射到主机的 5000 端口 depends_on: - nginx nginx: restart: always image: nginx:stable volumes: - ./webconf/nginx/conf.d/:/etc/nginx/conf.d/ - ./webconf/nginx/log/:/var/log/nginx/ - ./webconf/nginx/cert/:/opt/cert/ - ./webapp/app/static/:/opt/static/ ports: - "80:80" - "443:443" 

Dockerfile

# -------------------------- # Docker file # -------------------------- FROM python:3.6 # Set system language ENV LC_ALL C.UTF-8 ENV LANG C.UTF-8 # install python requirement COPY ./webapp/requirements.txt /tmp/requirements.txt RUN pip3 install -i https://pypi.tuna.tsinghua.edu.cn/simple --upgrade pip RUN pip3 install --no-cache-dir gunicorn RUN pip3 install -i https://pypi.tuna.tsinghua.edu.cn/simple -r /tmp/requirements.txt # Create root folder docker_web_app COPY ./webapp /docker_web_app/iodock/ WORKDIR /iodock/ # ENV PORT 5000 EXPOSE 5000 CMD ["/usr/local/bin/gunicorn", "-w", "2", "-b", ":5000", "manage:app"] 

nginx.conf

server { listen 80; server_name localhost; # 公网地址 access_log /var/log/nginx/nginx_access.log; error_log /var/log/nginx/nginx_error.log; location / { proxy_pass http://localhost:5000; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } location /static { alias /opt/static; proxy_set_header Host $host; # proxy_cache mycache; # expires 30d; } } 

nginx_error.log

2019/04/21 14:36:18 [error] 7#7: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 172.18.0.1, server: localhost, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:5000/", host: "0.0.0.0" 2019/04/21 14:36:18 [error] 7#7: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 172.18.0.1, server: localhost, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:5000/", host: "0.0.0.0" 2019/04/21 14:36:19 [error] 7#7: *1 no live upstreams while connecting to upstream, client: 172.18.0.1, server: localhost, request: "GET /favicon.ico HTTP/1.1", upstream: "http://localhost/favicon.ico", host: "0.0.0.0", referrer: "http://0.0.0.0/"