Remove a header based on query param with varnish - apache

I want to remove a cache-control header from URL's with a specific query params. e.g. when the query paramater ajax=1 is present.
e.g
www.domain.com?p=3&scroll=1&ajax=1&scroll=1
These are getting cached by chrome browsers for longer than I would like and I would like to stop that in this specific case. I have tried with .htaccess which works for static files however not in action on the URL's mentioned above.
RewriteEngine on
RewriteCond %{QUERY_STRING} (^|&)ajax=1(&|$)
Header unset "Cache-Control"
I could use a cache buster in the next website release but difficult in production and worried it would unnecessarily cache lots of files in user browsers so would rather achieve server side.
My server has Cloudflare then NGINX terminating SSL to Varnish then Apache with a Magento 2 instance running on there. So thinking i could possibly achieve this with NGINX or Varnish configs, or even Cloudflare. I however couldn't seem to find a way to achieve this with page rules in Cloudflare, or could not find examples for Varnish or Nginx.

I'm assuming you don't want to cache when ajax=1 is part of your URL params?
You can do this in Varnish using the following VCL snippet:
sub vcl_backend_response {
if(bereq.url ~ "\?([^&]*&)*ajax=1(&[^&]*)*$") {
set beresp.http.cache-control = "private, no-cache, no-store";
set beresp.uncacheable = true;
}
}
This snippet will make sure Varnish doesn't cache responses where the URL contains an ajax=1 URL parameter. It will also make sure any caching proxy that sits in front will not cache, because of the Cache-Control: private, no-cache, no-store.
Is this what you're looking for?

Related

HTTPS - Cookie "HttpOnly" and "secure "

My website is running under HTTPS protocol and I use only 1 cookie (PHPSESSID). My server is Apache 2.2.22. I noticed that my cookie doesn't have the "HttpOnly" and "Secure" headers, then I tried to set it via my .htaccess :
Header set Set-Cookie HttpOnly;Secure
By the way, the .htaccess works perfectly (url rewriting, deflate, expire headers, Etags etc...). But now... my website generates 4 cookies and PHPSESSID seems not to be secure :
Am i missing something ?
.htaccess is the wrong way to go about this.
PHP has session configuration options for this, you can either set them in your PHP configuration in the usual way (php.ini, ini_set, …), or via a dedicated function call.
session.cookie_httponly and session.cookie_secure are the relevant options here.
See http://php.net/manual/en/session.configuration.php and http://php.net/manual/en/function.session-set-cookie-params.php for additional details.

Apache Server: Redirection via http headers

I am trying to force browser to use https even when the user enters http URL. The idea is to use http response headers from the server. I am able to implement redirection using redirect (in site.conf) & Rewrite (which is disliked universally) but want to test out this method too.
Now I have tried adding the the following to my /etc/apache/sites-enabled/mysite.conf but despite the browser receiving the header response the user is not redirected to https (default apache page is shown):
Header set Location https://www.example.com/
Header set X-Forwarded-Proto: https
Header set Strict-Transport-Security "max-age=180; includeSubdomains"
Do I have to change anything else in the apache configuration to achieve this? (all modules are correctly loaded)
The Location header is only used for redirect responses (with a HTTP response code of 3XX) or Created responses (with a HTTP response code of 201):
https://www.rfc-editor.org/rfc/rfc7231#section-7.1.2
Just setting the header on a random page will not make the browser redirect.
When you use apache Redirect and Rewrite rules they set the response header AND add the location header. I really don't know why you'd want to do this manually.
And rewrite is not "universally disliked". It just overused when redirect would be simpler and more efficient in a lot of cases. If you need something more complicated then Rewrite is the right tool to use.
Finally you should not sent the Strict-Transport-Security header on a HTTP response (and the browser will rightly ignore it you do) but only on a HTTPS responses.

mod_rewrite: add a header if it doesn't already exist

I am attempting to add CORS handling using apache and mod_rewrite. The apache instance is front-ending multiple tomcat applications using mod_jk. Some of these applications have their own logic for adding CORS headers Access-Control-Allow-Origin, Access-Control-Max-Age, etc.
For the applications that didn't take care of the CORS logic, I would like to manage it on apache using mod rewrite.
Does anyone know if its possible to add a header to an HTTP response using mod_rewrite only if the header doesn't already exist? The browser reports an error if the CORS origin header is written twice.
mod_rewrite is to rewrite url's, not to set headers. What you want to use is mod_headers (documentation).
I don't know if mod_rewrite runs before mod_headers, but I would suggest to set environment variables using SetEnvIf instead (documentation).
You can do something like this:
SetEnvIf Request_URI "^/my/app/(.*)/?$" ADDHEADERS=1
Header set Access-Control-Max-Age 123456 env=ADDHEADERS

How to disable caching of a rewrite rule which proxies an internal server?

I'm using an htaccess rule to proxy to an internal server, using the answer recommended on this question, "Can ProxyPass and ProxyPassReverse Work in htaccess". I'm using htaccess as that is all I have access to. The method suggested works, but when I make a change on one of the internal pages and reload (from the external server) I don't even see it hitting the internal server, even after clearing the cache on the browser. In fact, if I try to load the page from another browser which never has tried to load the page before, it too gets the old copy.
This suggests something is being cached on the server, but how to change this? The apparent caching is rather annoying as I am trying to fix some issues that only occur on the proxied page.
If I hit the internal server directly and reload after a change, I always get the latest page.
I have tried a <filesMatch ...> rule for the affected pattern (using the same pattern as used in the RewriteRule in the following manner:
<filesMatch "^/?somedir/(.*)$">
Header set Cache-Control "max-age=0, private, no-store, no-cache, must-revalidate"
</filesMatch>
My rewrite rule looks like this, and comes after the filesMatch directive:
RewriteEngine On
RewriteRule ^/?somedir/(.*)$ https://internal.local.net:8000/$1 [L,P]
But this has not had any effect. I have also tried "NoCache *" but this directive causes an error as it is not allowed in an .htaccess file.
The P-flag in your RewriteRule causes the request to be proxied to the internal server using mod_proxy. mod_proxy by itself does not cache content. The caching is probably a result of mod_cache being enabled as well on the server. The settings you need to disable caching for your internal server can unfortunately only be done in server or virtual-host config. The solution would be to add what you tried to the configuration of the internal server thus telling mod_cache that it should not cache any response from your internal server:
Using .htaccess
Header set Cache-Control "max-age=0, private, no-store, no-cache, must-revalidate"
or PHP
header('Cache-Control: no-cache, no-store, must-revalidate'); // HTTP 1.1.
header('Pragma: no-cache'); // HTTP 1.0.
header('Expires: 0'); // Proxies.
Try adding this in an htaccess file in your "somedir" directory:
ExpiresActive On
ExpiresDefault "now"

How to remove a cookie in Apache

I need to remove a cookie from the HTTP request that gets to the server. Doing it on the client (that writes this cookie) or on the server (that reads it) is not an option. I have Apache 2.0 that proxies requests between client and the server, so I was hoping to remove the cookie right there in Apache using mod_rewrite.
My question is, is there a way to remove a certain cookie from the HTTP request using mod_rewrite?
If not possible to remove just one cookie then as a last resort to remove all cookies from the request?
I am open to other suggestions of how to accomplish this if mod_rewrite is not the right tool for this task.
Apache mod_rewrite allows manipulation of URLs but not of HTTP headers, however 'mod_headers' will let you do that.
So, you could use:
RequestHeader unset Cookie
This will strip all cookies from the request. I'm not sure if its possible to remove just a particular cookie using this technique.
Alternatively, you can stop cookies being passed back to the client using:
Header unset Set-Cookie
if that's more appropriate.
With Apache > 2.2.4, you could have used :
RequestHeader edit Cookie "^(.*?)ANY_COOKIE=.*?;(.*)$" $1$2
You can manage specific cookies using following statements in apache reverse proxy configurations:
To remove any specific cookie you can use:'Header add Set-Cookie "ANY_COOKIE='';expires='SOME_DATE_IN_PAST'; Max-Age=0; Path=COOKIE_PATH"'
By specifying past date, you tell the browser that the cookie has expired and browser will discard the cookie.
To add any cookie you can use:'Header add Set-Cookie "ANY_COOKIE='ANY_VALUE';expires='SOME_FUTURE_DATE'; Path=COOKIE_PATH"'
Be sure that you specify the some future date. If you do not specify any date, the cookie will be treated as session cookie.
Try using the following to remove specific cookie from request:
'RequestHeader add Cookie "ANY_COOKIE='';expires='SOME_PAST_DATE'; Path=COOKIE_PATH"'
I use this to unset all cookies (good to serve static content)
Header unset Cookie
Header unset Set-Cookie