老师，我的做的项目前端用的vue，后端用express提供api，按照教程，后端应用部署成功了，但部署vue项目的时候，就会报错>Error: listen EADDRINUSE :::5555

本地是可以运行的。

我改了几次端口，都报这个错误啊。。。vue、vue-cli、webpack、node、npm都已安装

错误截图：

ecosystem.json

{
    "apps": [
        {
            "name": "Blogfront",
            "script": "./build/dev-server.js",
            "env": {
                "COMMON_VARIABLE": "true"
            },
            "env_production": {
                "NODE_ENV": "production"
            }
        }
    ],
    "deploy": {
        "production": {
            "user": "fayin",
            "host": ["39.108.54.110"],
            "port": "3999",
            "ref": "origin/master",
            "repo": "https://github.com/CaptainLiao/blogfront.git",
            "path": "/www/blogfront/production",
            "ssh_options": "StrictHostKeyChecking=no",
            "post-deploy": "npm install && pm2 startOrRestart ecosystem.json --env production",
            "env": {
                "NODE_ENV": "production"
            }
        }
    }
}

nginx配置文件

upstream blogfront {
        server 127.0.0.1:5555;
}

server {
        listen 80;
        server_name www.fayinme.cn;
        location / {
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $http_host;

                proxy_set_header X-Nginx-Proxy true;

                proxy_pass http://blogfront;
                proxy_redirect off;
        }

        location ~* ^.+\.(jpg|jpeg|gif|png|ico|css|js|pdf|txt) {
                root /www/blogfront/production/current/public;
        }
}

求解。。。