apache rewrite_conf for apache cgi applications to mitigate full-cpu usage from badly behaving web robots usually in combination with more than one at the same time

bots-disable.conf

# koha-dev:/etc/apache2# cat bots-disable.conf

        RewriteEngine On

        # disable PetalBot
        RewriteCond %{HTTP_USER_AGENT} PetalBot [NC]
        RewriteRule .* - [F]

        # disable Barkrowler/0.9;
        RewriteCond %{HTTP_USER_AGENT} Barkrowler [NC]
        RewriteRule .* - [F]

        # disable bingbot
        RewriteCond %{HTTP_USER_AGENT} (bingbot) [NC]
        RewriteRule .* - [F]

        # disable megaindex.ru
        RewriteCond %{HTTP_USER_AGENT} megaindex [NC]
        RewriteRule .* - [F]

        # disable bytedance
        RewriteCond %{HTTP_USER_AGENT} Bytespider [NC]
        RewriteRule .* - [F]

        RewriteCond %{HTTP_USER_AGENT} facebookexternalhit [NC]
        RewriteRule .* - [F]

        RewriteCond %{HTTP_USER_AGENT} spider [NC]
        RewriteRule .* - [F]

        RewriteCond %{HTTP_USER_AGENT} crawler [NC]
        RewriteRule .* - [F]

        # disable bot all bot except Google
        RewriteCond %{HTTP_USER_AGENT} bot [NC]
#       RewriteCond %{HTTP_USER_AGENT} !Googlebot
#       RewriteCond %{HTTP_USER_AGENT} !IABot
        RewriteRule .* - [F]

        # disable GoogleOther something mobile crawler?
        RewriteCond %{HTTP_USER_AGENT} GoogleOther [NC]
        RewriteRule .* - [F]