nginx 502 Bad Gateway with NodeBB - nginx

Question

I get 502 bad gateway when connecting to my NodeBB installation using my domain
NodeBB is running on default port (4567)
My nginx seems to be configured properly (when connecting using the IP): http://puu.sh/mLI7U/0e03691d4c.png
My nodebb seems to be configured properly (when connecting using the IP):
http://puu.sh/mLI95/5fdafcaed9.png
My A record directing the IP to my VPS is configured properly.
Here is my etc/nginx/conf.d/example.com.conf
server {
listen 80;
server_name sporklounge.com;
location / {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_set_header X-NginX-Proxy true;
proxy_pass http://127.0.0.1:4567/;
proxy_redirect off;
# Socket.IO Support
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
}
}
My NodeBB config.json
{
"url": "http://localhost:4567",
"secret": "25d0d6a2-0444-49dc-af0c-bd693f5829d8",
"database": "redis",
"redis": {
"host": "127.0.0.1",
"port": "6379",
"password": "",
"database": "0"
}
}
Here is my var/log/nginx/error.log
2016/01/27 12:04:42 [error] 22026#0: *4062 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 50.186.224.26, server: sporklounge.com, request: "GET /favicon.ico HTTP/1.1", upstream: "http://127.0.0.1:80/favicon.ico", host: "sporklounge.com", referrer: "http://sporklounge.com/"
2016/01/27 12:21:06 [crit] 974#0: *1 connect() to 127.0.0.1:4567 failed (13: Permission denied) while connecting to upstream, client: 50.186.224.26, server: sporklounge.com, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:4567/", host: "sporklounge.com"
2016/01/27 12:21:07 [crit] 974#0: *1 connect() to 127.0.0.1:4567 failed (13: Permission denied) while connecting to upstream, client: 50.186.224.26, server: sporklounge.com, request: "GET /favicon.ico HTTP/1.1", upstream: "http://127.0.0.1:4567/favicon.ico", host: "sporklounge.com", referrer: "http://sporklounge.com/"
All help is greatly appreciated and I will answer all questions that i can to help get a solution, thank you!

Answer 1

The one thing I see is that according to the docs, your url config value should be the full web-accessible address that points to your NodeBB. That would be sporklounge.com, not the current value.
It could also be that the backend is just sometimes responding slowly. Try very high values of this value in Nginx to see if the backend eventually responds:
# For testing, allow very long response times.
proxy_read_timeout 5m;
Also, use netstat to confirm the backend is running on port 4567:
sudo netstat -nlp | grep ':4567'
Wait, the answer may right in your logs, which give you the reason for the connection failure:
(13: Permission denied) while connecting to upstream
See the related question:
(13: Permission denied) while connecting to upstream:[nginx]