ServerBuddies Support Blog

Webmin behaves differently depending on the operating system or Linux distribution that you have installed, and the particular version that you are running.

The correct OS is always automatically detected at installation time or provided by the installer, but it is quite possible that your system may be upgraded during the lifetime of the system.

If this happens, Webmin will not automatically detect the upgrade - you must tell it by following these steps :

1. Click on the Operating System and Environment icon on the module’s main page.
2. Select your Unix vendor and version from the New operating system list.
3. Hit the Save button to have Webmin start using it.

The operating system and version detected at installation time determines the default values for module configurations, as each flavor of Unix uses different locations and formats for the various config files that Webmin manages.

However, changing your OS by following the steps above will not adjust any of these configuration settings. Instead, it will just determine which ones are used for modules installed in future. Usually this is not a problem, as most OS upgrades will not change the locations of files and programs.

However, some modules may need to be manually configured after an upgrade - for example, you may need to change the print system used by the Printer Administration module if the old OS version used LPRng and the new version uses CUPS.

Setting up logging

Like most web servers, Webmin can be configured to create a lot file in the standard CLF format the records every request it receives. As well, it also creates a log of actions performed by users, such as the creation of a DNS zone or the deletion of a Unix group. This actions log can even include the details of every file changed and command run by each action, so that you can see what Webmin is doing under the hood.

Basic logging is enabled by default, but you can configure it further by following these steps :

1. Click on the Logging icon on the main page.
2. If Disable logging is selected then Webmin will write no logs at all. However, you should choose Enable logging to activate it.
3. If the Log resolved hostnames box is checked the log file will contain actual client hostnames instead of IP addresses. This can cause problems if reverse DNS lookups take a long time on your network, as one will need to be done for each request.
4. To prevent the log files from becoming too large, Webmin can be configured to truncate them periodically. To enable this feature, select the Clear logfiles every box and enter a number of hours into the adjacent text field.
5. To limit action logging to only specific users, select the Only log actions by option and choose some users from the list next to it. This can be handy if most of your users can only perform tasks that you don’t care much about, and you want to log only actions taken by the more powerful administrators instead.
6. To limit action logging to only specific modules, select the Only log actions in option and choose one or more modules from its list.
7. To enable the logging of file changes and commands run for each action, check the *Log changes made to files by each action *box. This will take up more disk space, but provides some very useful and interesting information.
8. Hit the Save button to activate the changes.

If you just want Webmin to be accessible via an URL subdirectory (like /webmin) on an Apache server without going to the trouble of configuring Apache to run the CGI scripts directly, there is a simpler method that can be used.

This is also useful if your system is only accessible on port 80, and you want access to both Webmin and a normal website. The steps to follow are :

Make sure mod_proxy is installed on your Apache webserver.

Add the following directives to the Apache configuration file:

ProxyPass /webmin/ http://localhost:10000/

ProxyPassReverse /webmin/ http://localhost:10000/

<Proxy *>

allow from all

</Proxy>

Add the lines webprefix=/webmin and webprefixnoredir=1 to /etc/webmin/config.

In /etc/webmin/config, add the line referer=apachehost, where apachehost is the hostname from the URL used to access Webmin via Apache.

If the referer line already has some hosts listed, add apachehost to it.

Re-start Apache to apply the configuration.

All requests to /webmin on the Apache server will then be passed through to the Webmin server on localhost port 10000.

All features should work fine, including themes, with the exception of IP access control (because as far as Webmin is concerned, all connections will be coming from localhost).

This method can also be used to make Webmin accessible via an Apache virtual host, like
http://webmin.yourdomain.com/.

The steps to follow are :

Make sure mod_proxy is installed on your Apache webserver.

Add a virtual host to your Apache configuration file like:

<VirtualHost _default_>
ServerName webmin.yourdomain.com
ProxyPass / http://localhost:10000/
ProxyPassReverse / http://localhost:10000/
<Proxy *>
allow from all
</Proxy>
</VirtualHost>

In /etc/webmin/config, add the line referer=apachehost, where apachehost is the hostname from the URL used to access Webmin via Apache.

If the referer line already has some hosts listed, add apachehost to it.

Re-start Apache to apply the configuration.

No changes need to be made to /etc/webmin/config, because no prefix is appended to the URL path.

Webmin Proxied Through Apache

If you just want Webmin to be accessible via an URL subdirectory (like /webmin) on an Apache server without going to the trouble of configuring Apache to run the CGI scripts directly, there is a simpler method that can be used.

This is also useful if your system is only accessible on port 80, and you want access to both Webmin and a normal website. This is the recommended method of making Webmin run within an existing website hierarchy.

The steps to follow are:

Make sure mod_proxy is installed on your Apache webserver.

Add the following directives to the Apache configuration file:

Add the lines webprefix=/webmin and webprefixnoredir=1 to /etc/webmin/config.

In /etc/webmin/config, add the line referer=apachehost, where apachehost is the hostname eg; hostname after the http:// from the URL used to access Webmin via Apache.

If the referer line already has some hosts listed, add apachehost to it or you can disable referrer checking all together by just using referer=1

Edit /etc/webmin/miniserv.conf and disable ssl redirect ssl_redirect=0 and ssl=0

Re-start Apache and Webmin to apply the configuration.

All requests to /webmin on the Apache server will then be passed through to the Webmin server on localhost port 10000. All features should work fine, including themes, with the exception of IP access control (because as far as Webmin is concerned, all connections will be coming from localhost).

This method can also be used to make Webmin accessible via an Apache virtual host, like http://webmin.yourdomain.com/.

The steps to follow are :

Make sure mod_proxy is installed on your Apache webserver.

Add a virtual host to your Apache configuration file like:

In /etc/webmin/config, add the line referer=apachehost, where apachehost is the hostname from the URL used to access Webmin via Apache. If the referer line already has some hosts listed, add apachehost to it.

Re-start Apache to apply the configuration.

No changes need to be made to /etc/webmin/config, because no prefix is appended to the URL path.