Apache 2 configuration tips

This howto is tested on:

• Debian 6.0 Squeeze

Prerequisites

This howto needs a Apache2 HTTP server installed as described in Install and setup Apache 2 on Debian.

Configurations

Debug RewriteRule rules

In order to debug RewriteRules rules, add these lines to the configuration of debugged VirtualHost:

RewriteLog /var/log/apache2/rewrite.log
RewriteLogLevel 5

Reload the server configuration:

/etc/init.d/apache2 reload

Open the log file:

command tail -f "/var/log/apache2/rewrite.log"

Reload the HTTP request to analyze.

Disable the HTTPS for a given URL

Provide the site domain name:

DOMAIN="www.domain.com"

It is simple to redirect all of HTTP requests to the HTTPS version of a site with a "Redirect Permanent" rule such a the one created by:

command a2tools -t "redirect" "${DOMAIN}" "https://${DOMAIN}/"

To disable this redirection for a unique URL, use :

command a2tools add-custom "${DOMAIN}" "  # Redirect everything but one URL match to https.
  RewriteEngine On
  RewriteCond "%{REQUEST_URI}?%{QUERY_STRING}" !^/public.php\?op=rss
  RewriteRule ^/(.*) https://${DOMAIN}/\$1 [R=301,L]

  # The root folder of this virtual host.
  DocumentRoot /opt/${DOMAIN}

  # Some options for the root folder.
  # Read Apache 2 documentation to know exactly what is done.
  <Directory /opt/${DOMAIN}>
    Options Indexes FollowSymLinks MultiViews

    # If you want to enable overrides, you should read:
    # http://httpd.apache.org/docs/2.0/mod/core.html#allowoverride
    AllowOverride Limit

    Order allow,deny
    Allow from all
  </Directory>"

Replace "/public.php\?op=rss" by the URL mask corresponding to the request you want to keep on HTTP.

Remove "?%{QUERY_STRING}" if the URL with redirection does not use GET parameters.

Redirect a HTTP access to HTTPS and keeping the host name

To automaticaly redirect HTTP accesses to a range of sub-domains to their HTTPS equivalents, provide the main domain name (used to name the created VirtualHost file):

DOMAIN="suffix.domain.com"

Provide the sub-domains to redirect selector (* select everything):

OTHER_DOMAINS="*-suffix.domain.com"

Create the setup redirecting all domains to their HTTPS equivalent (the line providing the redirection is bolded):

command a2tools add-custom --alias "${OTHER_DOMAINS}" "${DOMAIN}" "
  <IfModule mod_rewrite.c>
    RewriteRule    ^(.*)$   https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
  </IfModule>

  # Redirect every body to the HTTPS site.
  # This make sure that all users use secure version of the site.
  # Note the "permanent" : It is good for search engine optimization :D.
  Redirect permanent / https://${DOMAIN}/

  # This Location directives allow users to access the redirection.
  # Do not remove this if you want your site to work.
  <Location />
    Order deny,allow
    Allow from all
  </Location>"

Thanks

• Thanks to De geek à directeur technique (fr) for Configuration Apache en SSL avec wildcard (fr).