Topic: How to write RewriteRule ?

[Mox]

I need to write RewriteRule like this:

if it starts with /MyApp then /MyApp should be erased.

For example (original -> rewrited):
/MyApp/ -> /
/MyApp/Dir/file.html -> /Dir/file.html

How to do this?

[mraddi]

Hello Mox,

I have placed the following two lines into a .htaccess located in my document-root:

[Mox]

Thanks for that, but it didn't solve my problem.
Let me explain what exactly I am trying to do.

I have mapped subdomain to Tomcat webapp, and configured Apache to act as a proxy server like this:

[mraddi]

Good evening,

hopefully now I have understood the problem

One idea is to add another ProxyPass for MyApp so the absolute links including the MyApp still work

[tangent]

@mraddi beat me to my reply, and suggests a different approach, but I'll post what I'd composed.

@Mox - your follow-up post explains more clearly what you're trying to achieve.

As you've found out, mod_rewrite manipulates requests, not responses, so the response bodies from Tomcat need editing with an output filter to edit the embedded URI's / URL's, before being passed back to the requestor.

In the past I've solved this proxy to Tomcat problem with either mod_substitute or mod_proxy_html. It rather depends on the complexity of the responses from Tomcat, but I'd say mod_proxy_html is the more flexible and robust method. Both will take a bit of setting up and testing.

I'd normally use a location block to encapsulate the proxy directives to the Tomcat server, even though in this case you've decided to proxy the entire virtual host.

A few other points to consider:

If your content from Tomcat is compressed, you'll need to disable that so the output filter can see the uncompressed responses. Alternatively, you can add a "RequestHeader unset Accept-Encoding" directive to your configuration, but you'll then find it more challenging to compress the final response back to your clients.

Next, if your Tomcat server is remote to the proxy server, you'll need to edit or remove the host part of embedded URL's to match your Apache site URL. I'd personally edit these to be site relative, even for a local tomcat server, e.g. /image.png rather than http(s)://tomcat.domain.com/image.png

If your Apache server ever ends up behind a load balancer, or the service URL differs from your Apache ServerName, then you'll probably need to edit the response headers too. Again, I'd go for site relative, e.g.

[mraddi]

Good morning

@tangent: you are absolutely right - the clean way would be to modify the response instead of the request.
But it is easier and should be faster most times to modify the requests (compared to modifying the response) with the downside that the /MyApp/-path is not hidden but allowed as well.

[James Blond]

Only to say there is: mod_proxy_html[1]. That can be an option, too.



[1] https://httpd.apache.org/docs/2.4/mod/mod_proxy_html.html

[Mox]

Thanks for your suggestions.

This solution that mraddi posted works: