Installing webmin on Centos 5.x

For CentOS 5.1 -- First we install some dependencies. (This is already present on CentOS 5.2 and CentOS 5.3.)

yum -y install perl-Net-SSLeay

step 1: webmin

Install the system, using the link at http://www.webmin.com/download.html

cd /usr/src
wget <a href="http://superb-east.dl.sourceforge.net/sourceforge/webadmin/webmin-1.450-1.noarch.rpm">http://superb-east.dl.sourceforge.net/sourceforge/webadmin/webmin-1.450-1.noarch.rpm</a>
rpm -i webmin-1.450-1.noarch.rpm

Then you can start in your browser (note: https: ) at:

https://localhost:10000

Webmin permits login from the root user as well as anyone who has sudo privilege. To permit logging into webmin with your username and password, give yourself permission to execute the sudo command by using the visudo command (do not edit the file /etc/sudoers directly) and un-comment the line:

%wheel ALL=(ALL) ALL

step 2: usermin

You might also want usermin... for the latest version, check:

<a href="http://www.webmin.com/udownload.html">http://www.webmin.com/udownload.html</a>

For example, to install:

cd /usr/src
wget http://prdownloads.sourceforge.net/webadmin/usermin-1.360-1.noarch.rpm
rpm -Uvh usermin-1.360-1.noarch.rpm

Then point your browser to

https://localhost:20000

step 3: virtualmin

For managing virtual domains, there are both GPL and commercial version of Virtualmin. For many sites, the key difference will be that the paid version includes the ability to manage spam and email antivirus settings on a per-domain, per-user level, whereas the GPL doesn't.

<a href="http://www.virtualmin.com/">http://www.virtualmin.com/</a>

Download the install script and run it. Note, the installer for Centos 5 misses one permission setting. Users attempting to retrieve POP3 email can't login. If you manually connect to port 110 and login, you will see the error as follows:

$ telnet mailserver 110
Trying 192.168.1.20...
Connected to mailserver.domain.
Escape character is '^]'.
+OK Dovecot ready.
user user.domain
+OK
pass password
+OK Logged in.
-ERR [IN-USE] Couldn't open INBOX: Internal error occurred.
     Refer to server log for more information.

In the file /var/log/maillog you will see:

Feb 23 05:01:02 host dovecot: POP3(user.domain): mkdir(/var/lib/dovecot/index/user.domain/.INBOX) failed: Permission denied
Feb 23 05:01:02 host dovecot: POP3(user.domain): mkdir(/var/lib/dovecot/control/user.domain/.INBOX) failed: Permission denied
Feb 23 05:01:02 host dovecot: POP3(user.domain): mkdir(/var/lib/dovecot/index/user.domain/.INBOX) failed: Permission denied
Feb 23 05:01:02 host dovecot: POP3(user.domain): mkdir(/var/lib/dovecot/control/user.domain/.INBOX) failed: Permission denied
Feb 23 05:01:02 host dovecot: POP3(user.domain): Couldn't open INBOX: Internal error occurred. Refer to server log for more information. [2009-02-23 05:01:02]
Feb 23 05:01:02 host dovecot: POP3(user.domain): Couldn't open INBOX top=0/0, retr=0/0, del=0/0, size=0

To solve this, as root:

chmod 755 /var/lib/dovecot
chmod 777 /var/lib/dovecot/index /var/lib/dovecot/control

step 4: configuring spamassassin

Once Webmin is installed, spamassassin is very easy to turn on -- there is a button that will automatically create the correct entries in /etc/procmailrc ... the one missing link is that, by default, Postfix doesn't use that file. You can either manually add this line in /etc/postfix/main.cf:

mailbox_command = /usr/bin/procmail

or in Webmin, on the Local Delivery page of Postfix, set the parameter:

External command to use instead of mailbox delivery

to be:

/usr/bin/procmail

And that's all there is to getting SpamAssassin running.

step 5: change runlevel to avoid loading X

In your /etc/inittab, change the default runlevel from 5 to 3, so X won't load. That means no graphical login -- and a bunch of saved memory, if you're running a server instead of workstation.