Meteor,WebSocket,Nginx 502错误

我们正在尝试在Nginx后面的Debian服务器上运行Meteor应用程序.应用程序正在运行,但http://url/sockjs?info?cb=[random_string]返回时请求GET 502 Bad Gateway.

Nginx配置如下设置:

# this section is needed to proxy web-socket connections
map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

upstream app_server {
    server 127.0.0.1:3000; # for a web port socket (we'll use this first)
    # server unix:/var/run/app/app.sock;
}

server {
    listen       80;
    server_name  app_server.com;

    charset utf-8;
    client_max_body_size 75M;

    access_log  /var/log/nginx/app.access.log;
    error_log  /var/log/nginx/app.error.log;

    location / {
        proxy_pass http://app_server;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_set_header X-Forwarded-For $remote_addr; # preserve client IP
        proxy_read_timeout 60s;
        keepalive_timeout 65;
        proxy_redirect off;
        # the root path (/) MUST NOT be cached
        if ($uri != '/') {
            expires 30d;
        }
    }
}

我们已经尝试了各种配置,无法确定故障所在.使用nginx的Meteor WebSocket握手错误400的解决方案也不起作用.

编辑:尝试在meteor的推荐nginx配置中找到以下配置,它仍然返回502.

编辑:当不从Meteor CFS获取图像时,应用程序正常工作,Meteor CFS用于通过管理仪表板存储上传的图像.加载图像时,对域/ sockjs/img_location/cb/xhr_send的POST会导致502错误.