Linux System Administration

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Chapter 6: Administering Apache

Permissions problems can be fixed by changing the owner of the file to the process

running Apache.

Virtual Hosts Don’t Work

Use

# apache2ctl -S

for a quick check of your virtual host directives.

SSI Doesn’t Work

If you see lines like this in your error log (/var/log/apache2/error.log):

[error] an unknown filter was not added: INCLUDES

you didn’t enable mod_include. Run the command:

# a2enmod include

CGI Program Doesn’t Run

If you can’t get a CGI program to run, work through the following checklist:

• Has CGI been enabled, by one of the methods discussed earlier?

• Is the CGI program in a CGI directory like /var/cgi-bin, or does it have a suffix

like .php?

• Is the file readable? If not, use chmod.

• What does the Apache error log say?

• How about the system error log, /var/log/messages?

SSL Doesn’t Work

Check that you enabled the Apache SSL module (a2enmod ssl) and told Apache to

listen to port 443 in /etc/apache2/ports.conf:

Listen 443

If the directive wasn’t there, add it and restart Apache. Then try to access this URL in

your browser: https://server1.centralsoft.org. If it still doesn’t work, port 443 may be

blocked by a firewall. You can check this with nmap:

# nmap -P0 -p 443 server1.centralsoft.org

Starting nmap 3.70 ( http://www.insecure.org/nmap/ ) at 2006-08-01 22:38 CDT

Interesting ports on ... (...):

PORT STATE SERVICE

443/tcp open https

Nmap run completed -- 1 ...