Rails: 404 page not found using Nginx Web Server

I finally figured it out. The issue was from the Nginx configuration file:

Here’s how I solved it:

Modify this directive:

try_files $uri $uri/ @railsserver;

to this

try_files $uri @railsserver;

That is remove $uri/ from the line.

Since we aren’t going to be serving any index files (index.html) directly, there is no need for it to be present. It causes nginx to try to load the files specified in the index directive, or if none exist, to do a directory index.

And since no index file exists or no index directive exists in our Nginx configuration file due to the Nginx configuration is for a dynamic web application, Nginx returns the error 404 page not found.

So our configuration will look like this:

upstream railsserver {
        server 127.0.0.1:3000;
}

server {

        # Replace 'localhost' with your FQDN if you want to use
        # your app from remote or if you need to add a certificate 
        server_name localhost;

                root /home/deploy/my-website/public;

        # Define where Nginx should write its logs
        access_log /var/log/nginx/my-website/access.log;
        error_log /var/log/nginx/my-website/error.log;

        location / {
                 # First attempt to serve file(s) specified in the index directive,
                 # then the rails application directory
                 try_files $uri @railsserver;
        }
       
        location ~ ^/(assets/|robots.txt|humans.txt|favicon.ico) {
                expires max;
        }

        location @railsserver {
                proxy_set_header Host $http_host;
                proxy_set_header CLIENT_IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_read_timeout 300;
                proxy_pass http://railsserver;

                gzip on;
                gzip_types text/plain text/xml text/css image/svg+xml application/javas$
                gzip_proxied any;
        }
}

Next, restart Nginx using the command:

sudo systemctl restart nginx

You can check your website now via your browser, everything should be fine now.

Resources: Does Nginx require an index file for the root directory?

That’s all

I hope this helps