Linux System Administration

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Chapter 4: An Initial Internet-Ready Environment

Notice in Figure 4-19 that the status of sshd shows that it is running and that the sys-

tem is monitoring it. Three lines from the bottom of the screen, you can see the

instructions on what to do if sshd fails:

If failed localhost:22 [SSH] with timeout 5 seconds then restart else if recovered

then alert

This policy simply restarts a failed service and sends a message when it successfully

restarts.

Finally, monit provides four buttons at the bottom of the page for manual interven-

tion. Now, let’s see how this system works.

Installing and Configuring monit

To install monit, you can either use your Linux system package manager or down-

load the tarball from http://www.tildeslash.com/monit. If you’re using the Debian

setup from Chapter 2, simply enter:

# apt-get install monit

After you’ve installed monit, edit /etc/monit/monitrc. The file created during installa-

tion contains lots of examples, and you can find more configuration examples at

http://www.tildeslash.com/monit/doc/examples.php. In our case, we want to:

Figure 4-19. Drilling down to sshd

Safeguarding a Linux Web Server

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• Enable the monit web interface on port 2812.

• Monitor the proftpd, sshd, mysql, apache, and postfix services.

• Create a Secure Sockets Layer (https) web interface where ...