node.js app with nginx 502 bad gateway error

Replace

proxy_pass https://node_app_production;

with

proxy_pass http://node_app_production;

Restart the nginx and you should be all set. See nginx proxy pass Node, SSL?

I've resolved the issue with 2 steps.

1. Check /var/log/nginx/error.log

connect() failed (111: Connection refused) while connecting to upstream, client: *.*.*.*, server: *.*.*.*, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:8000/", host: "*.*.*.*"

       Upstream was still 127.0.0.1:8000 even if I set upstream to 127.0.0.1:3000 in nginx conf file.

2. Replace server 127.0.0.1:8000 with server 127.0.0.1:3000 in /etc/nginx/conf.d/virtual.conf and restart nginx.

server {
    listen       80;
    server_name  SERVER_IP_ADDRESS;

    location / {
        proxy_pass http://127.0.0.1:3000;
    }
}

sudo /etc/init.d/nginx restart 

Finally, it works with no 502 error.