使用 PM2 运行应用程序给我一个 502 错误

Question

I have a relatively basic Express app that I have sitting behind nginx.

Everything works fine when I run

sudo node server.js

I can access the website without incident.

However when I use

sudo pm2 start server.js I get an 'online' status and no errors (helpful), but when attempting to access the website I get a 502 error. The instructions for PM2 don't indicate any additional steps are required.

I've looked for solutions to this problem but they all seem slightly different (and there are a lot of them! I'm beginning to wonder if it works at all) - I've tried a few things, like targeting bin/www instead of server.js but no dice.

Do I need to perform additional setup for PM2 compatibility? Should I look for alternatives? What could be causing these problems?

Here is my current nginx config (improvements welcome), but I will stress that the setup works fine when not using PM2.

(Domain replaced with X )

server {
  listen 80;
  listen 443 ssl;

  server_name www.X.co.uk;

  ssl_certificate /etc/letsencrypt/live/X.co.uk/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/X.co.uk/privkey.pem;

  return 301 https://X.co.uk$request_uri;
}
server {
  listen 80;

  server_name X.co.uk;

  return 301 https://X.co.uk$request_uri;
}
server {
  listen 443 ssl;

  server_name X.co.uk;

  root /var/www/X;

  ssl_certificate /etc/letsencrypt/live/X.co.uk/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/X.co.uk/privkey.pem;

  location / {
    proxy_pass https://localhost:4003;
  }

  include /etc/nginx/h5bp/location/expires.conf;
  include /etc/nginx/h5bp/location/cross-domain-fonts.conf;
  include /etc/nginx/h5bp/location/protect-system-files.conf;
}

Thanks!

Answer 1

I had the same problem when installed certbot. But

sudo pm2 delete server
sudo pm2 start server.js

did the trick and everything began to work as expected!