29.8. Apache HTTP Server

Contributed by Murray Stokely.

The open source Apache HTTP Server is the most widely used web server. FreeBSD does not install this web server by default, but it can be installed from the www/apache24 package or port.

This section summarizes how to configure and start version 2.x of the Apache HTTP Server on FreeBSD. For more detailed information about Apache 2.X and its configuration directives, refer to httpd.apache.org.

29.8.1. Configuring and Starting Apache

In FreeBSD, the main Apache HTTP Server configuration file is installed as /usr/local/etc/apache2x/httpd.conf, where x represents the version number. This ASCII text file begins comment lines with a #. The most frequently modified directives are:

ServerRoot "/usr/local"

Specifies the default directory hierarchy for the Apache installation. Binaries are stored in the bin and sbin subdirectories of the server root and configuration files are stored in the etc/apache2x subdirectory.

ServerAdmin you@example.com

Change this to the email address to receive problems with the server. This address also appears on some server-generated pages, such as error documents.

ServerName www.example.com:80

Allows an administrator to set a hostname which is sent back to clients for the server. For example, www can be used instead of the actual hostname. If the system does not have a registered DNS name, enter its IP address instead. If the server will listen on an alternate report, change 80 to the alternate port number.

DocumentRoot "/usr/local/www/apache2x/data"

The directory where documents will be served from. By default, all requests are taken from this directory, but symbolic links and aliases may be used to point to other locations.

It is always a good idea to make a backup copy of the default Apache configuration file before making changes. When the configuration of Apache is complete, save the file and verify the configuration using apachectl. Running apachectl configtest should return Syntax OK.

To launch Apache at system startup, add the following line to /etc/rc.conf:

apache24_enable="YES"

If Apache should be started with non-default options, the following line may be added to /etc/rc.conf to specify the needed flags:

apache24_flags=""

If apachectl does not report configuration errors, start httpd now:

# service apache24 start

The httpd service can be tested by entering http://localhost in a web browser, replacing localhost with the fully-qualified domain name of the machine running httpd. The default web page that is displayed is /usr/local/www/apache24/data/index.html.

The Apache configuration can be tested for errors after making subsequent configuration changes while httpd is running using the following command:

# service apache24 configtest

Note:

It is important to note that configtest is not an rc(8) standard, and should not be expected to work for all startup scripts.

29.8.2. Virtual Hosting

Virtual hosting allows multiple websites to run on one Apache server. The virtual hosts can be IP-based or name-based. IP-based virtual hosting uses a different IP address for each website. Name-based virtual hosting uses the clients HTTP/1.1 headers to figure out the hostname, which allows the websites to share the same IP address.

To setup Apache to use name-based virtual hosting, add a VirtualHost block for each website. For example, for the webserver named www.domain.tld with a virtual domain of www.someotherdomain.tld, add the following entries to httpd.conf:

<VirtualHost *>
    ServerName www.domain.tld
    DocumentRoot /www/domain.tld
</VirtualHost>

<VirtualHost *>
    ServerName www.someotherdomain.tld
    DocumentRoot /www/someotherdomain.tld
</VirtualHost>

For each virtual host, replace the values for ServerName and DocumentRoot with the values to be used.

For more information about setting up virtual hosts, consult the official Apache documentation at: http://httpd.apache.org/docs/vhosts/.

29.8.3. Apache Modules

Apache uses modules to augment the functionality provided by the basic server. Refer to http://httpd.apache.org/docs/current/mod/ for a complete listing of and the configuration details for the available modules.

In FreeBSD, some modules can be compiled with the www/apache24 port. Type make config within /usr/ports/www/apache24 to see which modules are available and which are enabled by default. If the module is not compiled with the port, the FreeBSD Ports Collection provides an easy way to install many modules. This section describes three of the most commonly used modules.

29.8.3.1. SSL support

At one in point in time, support for SSL inside of Apache required a secondary module called mod_ssl. This is no longer the case and the default install of Apache comes with SSL built into the web server. An example of how to enable support for SSL websites is available in the installed file, httpd-ssl.conf inside of the /usr/local/etc/apache24/extra directory. Inside this directory is also a sample file called named ssl.conf-sample. It is recommended that both files be evaluated to properly set up secure websites in the Apache web server.

After the configuration of SSL is complete, the following line must be uncommented in the main http.conf to activate the changes on the next restart or reload of Apache:

#Include etc/apache24/extra/httpd-ssl.conf

Warning:

SSL version two and version three have known vulnerability issues. It is highly recommended TLS version 1.2 and 1.3 be enabled in place of the older SSL options. This can be accomplished by setting the following options in the ssl.conf:

SSLProtocol all -SSLv3 -SSLv2 +TLSv1.2 +TLSv1.3
SSLProxyProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1

To complete the configuration of SSL in the web server, uncomment the following line to ensure that the configuration will be pulled into Apache during restart or reload:

# Secure (SSL/TLS) connections
Include etc/apache24/extra/httpd-ssl.conf

The following lines must also be uncommented in the httpd.conf to fully support SSL in Apache:

LoadModule authn_socache_module libexec/apache24/mod_authn_socache.so
LoadModule socache_shmcb_module libexec/apache24/mod_socache_shmcb.so
LoadModule ssl_module libexec/apache24/mod_ssl.so

The next step is to work with a certificate authority to have the appropriate certificates installed on the system. This will set up a chain of trust for the site and prevent any warnings of self-signed certificates.

29.8.3.2. mod_perl

The mod_perl module makes it possible to write Apache modules in Perl. In addition, the persistent interpreter embedded in the server avoids the overhead of starting an external interpreter and the penalty of Perl start-up time.

The mod_perl can be installed using the www/mod_perl2 package or port. Documentation for using this module can be found at http://perl.apache.org/docs/2.0/index.html.

29.8.3.3. mod_php

Written by Tom Rhodes.

PHP: Hypertext Preprocessor (PHP) is a general-purpose scripting language that is especially suited for web development. Capable of being embedded into HTML, its syntax draws upon C, Java™, and Perl with the intention of allowing web developers to write dynamically generated webpages quickly.

Support for PHP for Apache and any other feature written in the language, can be added by installing the appropriate port.

For all supported versions, search the package database using pkg:

# pkg search php

A list will be displayed including the versions and additional features they provide. The components are completely modular, meaning features are enabled by installing the appropriate port. To install PHP version 7.4 for Apache, issue the following command:

# pkg install mod_php74

If any dependency packages need to be installed, they will be installed as well.

By default, PHP will not be enabled. The following lines will need to be added to the Apache configuration file located in /usr/local/etc/apache24 to make it active:

<FilesMatch "\.php$">
    SetHandler application/x-httpd-php
</FilesMatch>
<FilesMatch "\.phps$">
    SetHandler application/x-httpd-php-source
</FilesMatch>

In addition, the DirectoryIndex in the configuration file will also need to be updated and Apache will either need to be restarted or reloaded for the changes to take effect.

Support for many of the PHP features may also be installed by using pkg. For example, to install support for XML or SSL, install their respective ports:

# pkg install php74-xml php74-openssl

As before, the Apache configuration will need to be reloaded for the changes to take effect, even in cases where it was just a module install.

To perform a graceful restart to reload the configuration, issue the following command:

# apachectl graceful

Once the install is complete, there are two methods of obtaining the installed PHP support modules and the environmental information of the build. The first is to install the full PHP binary and running the command to gain the information:

# pkg install php74
# php -i |less

It is necessary to pass the output to a pager, such as the more or less to easier digest the amount of output.

Finally, to make any changes to the global configuration of PHP there is a well documented file installed into /usr/local/etc/php.ini. At the time of install, this file will not exist because there are two versions to choose from, one is php.ini-development and the other is php.ini-production. These are starting points to assist administrators in their deployment.

29.8.3.4. HTTP2 Support

Apache support for the HTTP2 protocol is included by default when installing the port with pkg. The new version of HTTP includes many improvements over the previous version, including utilizing a single connection to a website, reducing overall roundtrips of TCP connections. Also, packet header data is compressed and HTTP2 requires encryption by default.

When Apache is configured to only use HTTP2, web browsers will require secure, encrypted HTTPS connections. When Apache is configured to use both versions, HTTP1.1 will be considered a fall back option if any issues arise during the connection.

While this change does require administrators to make changes, they are positive and equate to a more secure Internet for everyone. The changes are only required for sites not currently implementing SSL and TLS.

Note:

This configuration depends on the previous sections, including TLS support. It is recommended those instructions be followed before continuing with this configuration.

Start the process by enabling the http2 module by uncommenting the line in /usr/local/etc/apache24/httpd.conf and replace the mpm_prefork module with mpm_event as the former does not support HTTP2.

LoadModule http2_module libexec/apache24/mod_http2.so
LoadModule mpm_event_module libexec/apache24/mod_mpm_event.so

Note:

There is a separate mod_http2 port that is available. It exists to deliver security and bug fixes quicker than the module installed with the bundled apache24 port. It is not required for HTTP2 support but is available. When installed, the mod_h2.so should be used in place of mod_http2.so in the Apache configuration.

There are two methods to implement HTTP2 in Apache; one way is globally for all sites and each VirtualHost running on the system. To enable HTTP2 globally, add the following line under the ServerName directive:

Protocols h2 http/1.1

Note:

To enable HTTP2 over plaintext, use h2 h2c http/1.1 in the httpd.conf.

Having the h2c here will allow plaintext HTTP2 data to pass on the system but is not recommended. In addition, using the http/1.1 here will allow fallback to the HTTP1.1 version of the protocol should it be needed by the system.

To enable HTTP2 for individual VirtualHosts, add the same line within the VirtualHost directive in either httpd.conf or httpd-ssl.conf.

Reload the configuration using the apachectl reload command and test the configuration either by using either of the following methods after visiting one of the hosted pages:

# grep "HTTP/2.0" /var/log/httpd-access.log

This should return something similar to the following:

192.168.1.205 - - [18/Oct/2020:18:34:36 -0400] "GET / HTTP/2.0" 304 -
192.0.2.205 - - [18/Oct/2020:19:19:57 -0400] "GET / HTTP/2.0" 304 -
192.0.0.205 - - [18/Oct/2020:19:20:52 -0400] "GET / HTTP/2.0" 304 -
192.0.2.205 - - [18/Oct/2020:19:23:10 -0400] "GET / HTTP/2.0" 304 -

The other method is using the web browser's built in site debugger or tcpdump; however, using either method is beyond the scope of this document.

Support for HTTP2 reverse proxy connections by using the mod_proxy_http2.so module. When configuring the ProxyPass or RewriteRules [P] statements, they should use h2:// for the connection.

29.8.4. Dynamic Websites

In addition to mod_perl and mod_php, other languages are available for creating dynamic web content. These include Django and Ruby on Rails.

29.8.4.1. Django

Django is a BSD-licensed framework designed to allow developers to write high performance, elegant web applications quickly. It provides an object-relational mapper so that data types are developed as Python objects. A rich dynamic database-access API is provided for those objects without the developer ever having to write SQL. It also provides an extensible template system so that the logic of the application is separated from the HTML presentation.

Django depends on mod_python, and an SQL database engine. In FreeBSD, the www/py-django port automatically installs mod_python and supports the PostgreSQL, MySQL, or SQLite databases, with the default being SQLite. To change the database engine, type make config within /usr/ports/www/py-django, then install the port.

Once Django is installed, the application will need a project directory along with the Apache configuration in order to use the embedded Python interpreter. This interpreter is used to call the application for specific URLs on the site.

To configure Apache to pass requests for certain URLs to the web application, add the following to httpd.conf, specifying the full path to the project directory:

<Location "/">
    SetHandler python-program
    PythonPath "['/dir/to/the/django/packages/'] + sys.path"
    PythonHandler django.core.handlers.modpython
    SetEnv DJANGO_SETTINGS_MODULE mysite.settings
    PythonAutoReload On
    PythonDebug On
</Location>

Refer to https://docs.djangoproject.com for more information on how to use Django.

29.8.4.2. Ruby on Rails

Ruby on Rails is another open source web framework that provides a full development stack. It is optimized to make web developers more productive and capable of writing powerful applications quickly. On FreeBSD, it can be installed using the www/rubygem-rails package or port.

Refer to http://guides.rubyonrails.org for more information on how to use Ruby on Rails.

All FreeBSD documents are available for download at https://download.freebsd.org/ftp/doc/

Questions that are not answered by the documentation may be sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.