Ubuntu Apache: httpd.conf or apache2.conf?

Solution 1:

The httpd.conf is designed for user configurations. You really should not edit the apache2.conf as it may be updated by future upgrades.

An additional option is to just put your custom configuration into /etc/apache2/conf.d, all files in this directory are included as well.

Solution 2:

These are not your only options. On Ubuntu/Debian, Apache also processes all the files in /etc/apache2/sites-enabled/ (which should be symlinks to files in sites-available/ directory, managed by the a2ensite and a2dissite programs)

You're intended to use these directories for VirtualHosts.

Solution 3:

apache2.conf includes httpd.conf:

a@test$:/etc/apache2$ cat apache2.conf | grep httpd.conf 
Include /etc/apache2/httpd.conf

I think that httpd.conf is deprecated, but just left in there for conservative people so that they find they way around... :)

EDIT:

After reading Rob's answer, I did a better grep:

a@test:/etc/apache2$ grep -C 1 httpd.conf apache2.conf 
# Include all the user configurations:
Include /etc/apache2/httpd.conf

User configurations it is...

Solution 4:

The Apache Software Foundation publishes many bits of software, one of which is a web server named httpd. The httpd project sources include among other things an httpd.conf sample configuration file, which is installed by default in /usr/local/etc/httpd or /etc/httpd. You will find httpd named as such on most systems.

However, long ago and far away, someone in the Debian GNU/Linux distribution decided to change the name of the software within that distribution from httpd to apache2. Thus on a Debian system you will find a configuration file named apache2.conf in a directory named /etc/apache2. I don't know who did this or why, but it's a perennial source of confusion on par with calling Windows "Microsoft" or ESXi "VMware". Distributions based on Debian, such as Ubuntu, inherit this strangeness. Even stranger, they then include a file /etc/apache2/httpd.conf which is Included from apache2.conf into which users can place custom configuration.

So the answer is, if you're on a Debian-based system, you bend your brain into doing things the way Debian wants you to do it. Otherwise you generally do things the normal way as the upstream httpd project does it.

Solution 5:

Apache 2.4 (under Debian/Ubuntu)

For Configuration/Overrides (not necessarily a new site):

Place a new configuration file in /etc/apache2/conf-available/{name}.conf.

Enable/Disable your new config using sudo a2enconf {name}or sudo a2disconf {name}.

Directives in these can also override httpd.conf or apache2.conf as any additional config files added by user are read in last after main config.

Restart apache2 service to reflect the change.

For Sites (and any site specific configuration overrides):

Place a new site file in /etc/apache2/sites-available/{name}.conf

Enable/Disable your site config using sudo a2ensite {name}or sudo a2dissite {name}.

Restart apache2 service to reflect the change.

Don't use:

httpd.conf is still installed as main config file on some Linux distributions. On others, you should NOT see it anymore - if you do, leave it empty as installed if you wish to upgrade Apache cleanly/easily via package manager.

apache2.conf is still installed on many systems and is used as the main configuration file for Debian/Ubuntu. But, leave it alone if you wish to upgrade Apache cleanly/easily. You should see some include statements near the bottom of this file for sites and custom configurations.
Use them instead!

One, or both of these files may be installed via your Linux package manager depending on the Linux distribution. This is a good reason NOT to touch them since they could accidentally be overwritten during a system upgrade in the future.

Anything you might see in "global" Apache2 configuration files can be added/overridden under your custom config as per above. You can also use include statements yourself to further customize. Example: You could include additional SSL directives you want on some/all sites from a specific custom include file. You would just add this include statement to all your virtual site configs as needed.

More (Debian/Ubuntu): https://stackoverflow.com/a/11687212/503621