Nginx reverse proxy with Tomcat - WebSocet connection not being served correctly

Question

Hello,

I’m currently working on a somewhat convoluted setup for a Tomcat-based web application, and I’m having trouble getting Nginx to work as a reverse proxy. My application has multiple components with specific routing requirements that I’m struggling to configure correctly so I decided to ask the community here.

To summarise my setup

The main Tomcat application is hosted on domain1.com:8080 and has a REST API endpoint at domain1.com:8080/api.
There is another sub-application with a WebSocket connection hosted on domain2.com:8080/ws.
Both applications share some static resources located at domain1.com:8080/static, which should be served directly by Nginx.

I’ve tried configuring Nginx with the following settings, but I’m still having issues with the routing:

http {
    upstream tomcat_server {
        server domain1.com:8080;
    }

    server {
        listen 80;
        server_name domain1.com;

        location /static/ {
            root /path/to/static/files;
        }

        location / {
            proxy_pass http://tomcat_server;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }

        location /api/ {
            proxy_pass http://tomcat_server;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }
    }

    server {
        listen 80;
        server_name domain2.com;

        location /ws/ {
            proxy_pass http://tomcat_server;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }
    }
}

I’ve removed my actual domains from the configuration file.

I’m still experiencing issues with the WebSocket connections and some static resources are not being served correctly. I’m not sure if I’m missing any important Nginx directives or if the configuration itself is incorrect.

If you need more information about my current setup, I’ll be happy to provide it.

KFSys · Accepted Answer

Heya,

Based on your description and configuration, I have some suggestions to improve your Nginx configuration.

Use alias instead of root for the /static/ location block. This is because alias is used when the URL path and the file system path don’t match exactly.
Add a trailing slash to the proxy_pass directive for the /api/ and /ws/ location blocks. This helps in avoiding any potential routing issues.
Add the X-Forwarded-For header to pass along the client’s IP address to the Tomcat application. This can be helpful for logging and debugging purposes.
Add proxy_http_version 1.1; to the /ws/ location block to ensure that the WebSocket connection uses HTTP/1.1.

Now, I haven’t exactly tested it just because it’s hard to recreate your setup exactly but I think this should do the trick:

http {
    upstream tomcat_server {
        server domain1.com:8080;
    }

    server {
        listen 80;
        server_name domain1.com;

        location /static/ {
            alias /path/to/static/files;
        }

        location / {
            proxy_pass http://tomcat_server;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        location /api/ {
            proxy_pass http://tomcat_server/api/;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }
    }

    server {
        listen 80;
        server_name domain2.com;

        location /ws/ {
            proxy_pass http://tomcat_server/ws/;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_http_version 1.1;
        }
    }
}

If you still encounter any issues, please provide more details about the specific errors or problems you’re facing, and we can further help you troubleshoot the issue.

Question

Nginx reverse proxy with Tomcat - WebSocet connection not being served correctly

Try DigitalOcean for free

Popular Topics

Get our biweekly newsletter

Hollie's Hub for Good

Become a contributor

Featured on Community

DigitalOcean Products

Welcome to the developer cloud