A reverse proxy in the network is used to forward and balance traffic to multiple servers.

As a result, most web servers need to configure the reverse proxy for faster communication between client and web server.

At Bobcares, we often get requests from our customers to configure the reverse proxy in Webmin as part of our Server Management Services.

Today, we’ll see how our Support Engineers configure Webmin reverse proxy and fix the related errors with it.

How we configure Webmin reverse proxy?

Let’s see how our Support Engineers set up Nginx as a reverse proxy in the customer’s Webmin control panel.

Here’re the steps we execute to configure Nginx reverse proxy in Webmin.

1. First, we login to Webmin, and go to Webmin > Servers > Nginx Webserver to check the availability of Nginx on the server.

2. Then, we run the following command to install Nginx plugin and start the services.

yum install nginx

/etc/init.d/nginx start

yum install wbm-virtualmin-nginx wbm-virtualmin-nginx-ssl

3. Next, we return to Virtualmin/Webmin and go to System Settings > Features and Plugins.

4. And check the “Nginx website” and “Nginx SSL website” features, then click save.

5. Then go to the System Information page and click Refresh system information in the top right.

6. Finally, we verify the status of Nginx as running in the “Status” section.

Common issues after enabling reverse proxy in Webmin

From our experience in managing servers, we’ve seen that customers facing different kinds of problems after enabling reverse proxy in Webmin.

Let’s see how our Support Team solved common errors.

1. Wrong redirects behind Nginx reverse proxy

Recently, one of our customers reported us with a problem regarding redirection trouble in the Linux iptables firewall module. He edited the firewall rules in the iptables and then tried to access URL “https://www.example.com/webmin/firewall/save_rule.cgi”. Then, it resulted in HTTP 404 error. Also, he got this error in other modules like Scheduled Cron Jobs and BIND DNS Server as well.

This error happens when the redirection is not set properly and when you access the URL with https it shows like HTTP 404 error.

So, to solve this error we took the following steps.

1. We checked /etc/miniserv.conf file to see if the ssl  value enabled or not

2. For redirection to access properly, we should set the value to 1 ie.,

ssl=1

3. And then we restarted the services to reflect the changes made in the configuration file.

This allowed users to access URL with https by using proper redirection settings.

2. Bad setting in Webmin configuration file

Moreover, if there is a bad setting in the Webmin configuration file and when you try to access Webmin URL “https://example.com”.

You may get a message like the following:

If this is a legitimate link, you can allow links from this URL as follows :
Login to Webmin normally.
Go to the Webmin Configuration module.
Click on the Trusted Referrers icon.
...

Our Support Engineers took the following steps to solve the issue.

1. First, we opened /etc/webmin/config in vi editor and we looked for the line “referer”.

2. Then we added the Webmin hostname as shown below.

referer=hostname

3. Finally, we restarted the service by running the command:

/etc/init.d/webmin restart

That fixed the problem. Now, the user could access the Webmin URL without any failure.

[Having trouble after setting Webmin reverse proxy? We’ll fix it for you.]

Conclusion

In short, Webmin reverse proxy enhances website performance with compression, encryption and caching. Today, we saw how our Support Engineers set up Webmin reverse proxy and fixed the related errors.