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

[yuting0501]

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/"

[jerry]

nginx 的 localhost:5000 改成 webapp:5000

[yuting0501]

@jerry 非常感谢！成功了，原来是要指明容器对象

[Kilerd]

顺便把 flask 里面的

- "5000:5000" # web 容器内的 5000 端口映射到主机的 5000 端口

这一样删了吧，都通过 nginx 访问了， 就没有必要暴露出原始端口了

[yuting0501]

@Kilerd 有道理，我试试看，谢谢！

[wangy]

支持一下！

[honglongmen]

@yuting0501
@Kilerd 正好顺便请教下,我用 portainer 部署了个 gitlab-ce,通过 cdn 访问总是间隔性有 422 出错提示:

下面是 nginx 的的配置,是否 proxy_pass http://127.0.0.1:8880; 这个我也要改为 docker 的容器对象名才可?

location /
{
location ~ .*\.(php|jsp|cgi|asp|aspx|flv|swf|xml)?$
{
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header REMOTE-HOST $remote_addr;
proxy_pass http://127.0.0.1:8880;

}
proxy_pass http://127.0.0.1:8880;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header REMOTE-HOST $remote_addr;


以下为 docker ps:

[root@back ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ed82dc089c7e gitlab/gitlab-ce:latest "/assets/wrapper" 3 weeks ago Up 9 days (healthy) 0.0.0.0:8222->22/tcp, 0.0.0.0:8880->80/tcp, 0.0.0.0:8443->443/tcp Gitlab-CE

807229f4387e portainer/portainer "/portainer" 3 weeks ago Up 9 days 0.0.0.0:9000->9000/tcp

[yuting0501]

@honglongmen 你可以试试看，但按我的了解，如果是配置错了应该是必定不工作

[honglongmen]

@yuting0501 容器对象我是写 CONTAINER ID:ed82dc089c7e 好还是 NAMES:Gitlab-CE 好呢

[yuting0501]

@honglongmen 囧，不太懂，其实我是搞嵌入式单片机的。。。

[yuting0501]

更新一下贴子，修改为`webapp:5000`不是正确的解法，nginx 报错，猜测是因为 nginx 无法识别 webapp 所以变成类似`:5000`? 所以我试了一下`0.0.0.0:5000`，可以成功运行。之前一直纳闷为什么 nginx 可以识别 docker-compose.yml 中的 webapp 参数，现在似乎说得通了。

[yuting0501]

抱歉，上一条回复是错误的，虽然 nginx 会报警告，：
nginx: [emerg] host not found in upstream "webapp" in /etc/nginx/conf.d/nginx.conf:10

对 docker-compose network 配置没有深入了解，这里得指定 docker-compose 网络名，具体细节请参考：
https://docs.docker.com/compose/networking/