Recommended method to configure custom maintenance page with Shibboleth SP and Apache HTTPD

[Dang, Minh (GE Global Research)]

I'm using Shibboleth SP with Apache HTTPD in front of Apache Tomcat. What is the recommended way to configure a custom maintenance page?

Without Shibboleth, I usually do the following with Apache HTTPD. Create rewrite rules to redirect all traffic to a custom maintenance page if a certain file (maintenance.enable) exists. That way I can just create that file and all traffic is directed to the custom maintenance page without having to restart HTTPD. This doesn't seem to work the same with Shibboleth SP protecting resources. In some cases I get the default "Service Temporarily Unavailable" page instead of the custom one I've created.

I can get around this if I disable Shibboleth SP during maintenance. This works, but I'm trying to avoid the need to restart HTTPD or Shibboleth SP.

Any help would be greatly appreciated. Thanks!

- Minh