htmlapachereverse-proxyssi

With Apache, how to interpret SSI on a page returned from another server using reverse proxy?

Using apache, I am trying to achieve the following scenario using SSI:

  1. Http request comes to Server1
  2. Server1 redirects the request to Server2 (reverse proxy)
  3. Server2 returns the html page with SSI directives in it
  4. Server1 has to interpret the SSI directives from the returned page
  5. Server1 should display returned page with the interpreted SSI directive to the user.

The following configuration in .htaccess works fine, if I try to render the page that resides within Server1 (after commenting out the rewrite rule - RewriteRule (.*) http://172.24.0.2:80/index.html [P])

AddDefaultCharset UTF-8
RewriteEngine On
RewriteRule (.*) http://172.24.0.2:80/index.html [P]

## Enable server side includes
Options +Includes

# Filter .html files through mod_include first
AddType text/html .html
AddOutputFilter INCLUDES .html

The following is the SSI directive that I am trying to include:

<!--#echo var="DATE_LOCAL" -->

The problem is, when apache in Server1 renders the page, it displays the SSI directive as it is (html comment).

I think I am missing out some configuration to tell apache to interpret it, once the response comes back after redirection.

Solution

  • The root cause of the problem: Server1 is returning compressed content. Apache won't un-compress it to apply SSI rules by default. It can be solved with the following 2 options:

    Option1:

    Force apache in Server1 to refuse to support compression using the following option in .htaccess:

    RequestHeader unset Accept-Encoding

    My updated .htaccess file looks like the following:

    RequestHeader unset Accept-Encoding
AddDefaultCharset UTF-8
RewriteEngine On
RewriteRule (.*) http://172.24.0.2:80/index.html [P]

## Enable server side includes
Options +Includes

# Filter .html files through mod_include first
AddType text/html .html
AddOutputFilter INCLUDES .html

    Option2:

    Uncompress the incoming data with mod_deflate module using the following option in .htaccess:

    SetOutputFilter INFLATE;DEFLATE

    My updated .htaccess file looks like the following:

    AddDefaultCharset UTF-8
RewriteEngine On
RewriteRule (.*) http://172.24.0.2:80/index.html [P]

## Enable server side includes
Options +Includes

# Filter .html files through mod_include first
AddType text/html .html
AddOutputFilter INCLUDES .html
SetOutputFilter INFLATE;DEFLATE

    The excerpts in apache config for the above solution would look like the following:

    <Location />
   SetOutputFilter INFLATE;DEFLATE;INCLUDES
   SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png|css|js|zip|gz)$ no-gzip dont-vary
</Location>

    Reference: http://www.apachetutor.org/admin/reverseproxies