Hi, How can use PHP code to clear fastcgi_cache file??

[nottellyou]

Hi, How can use PHP code to clear fastcgi_cache file??

[hpatoio]

Just send an HTTP request to the correct URL using curl or your favorite library.

[mtx-z]

Here someone did a PHP script that, using URL, re-build the cache filename to delete it (selective purge).
Not tested yet, I'll. Also i'll check how filename are generated to see if patterns match.

EDIT: here we can see

Both the key and file name in a cache are a result of applying the MD5 function to the proxied URL. The levels parameter defines hierarchy levels of a cache. For example, in the following configuration

fastcgi_cache_path /data/nginx/cache levels=1:2 keys_zone=one:10m;
file names in a cache will look like this:

/data/nginx/cache/c/29/b7f54b2df7773722d382f4809d65029c

I'm trying to match something

EDIT 2: i'm not able to build the correct cache filepath/filename using the linked script. I contacted the author to know more about how and where he found the filepath build pattern. You can see my last comment on the digitalocean post.

EDIT3: on typical purge system, the parameter (url) sended to the purge is build like $scheme$request_method$host$1 wich give us something like httpGETwww.domain.com (homepage) but PHP script is still wrong on the filename/path.

Some test i made : http://img4.hostingpics.net/pics/827481fastcgifilenamecache.png

For now, it seem that building the cache filepath/name using MD5 value of the fastcgi_cache_key of the given url is not working.

Achieving the right cache file delete from PHP would more lot more efficient than curl-ing the cache purge URL location i think.

[jesinwp]

Hi @mtx-z,

I'm the author of that article, I've replied to your comment.

Are you adding the slash at the end of the domain when doing a curl request like

curl -d 'url=http://www.example.com/' http://domainname.com/purge.php

[mtx-z]

Hi, thanks for answering.

Actually I'm not using the script with a curl, I want to use it directly from some php script.
That's why I'm testing the script on some URL to test if I can match the cache file name.

Have you looked at the screenshot I made? I set the cache key as header to then pass it in your script (just for test) in a sandbox but it 'ever match the name.

From the cache key, I tried removing the last slash, add it, remove some part... To pass the string to your script but never matched the actual cache file name and path.

I also tried using all your script with a full URL, and just from the $hash variable creation with the cache key directly.

I wasn't able to find any code from fastcgi module from where the filename and filepath are builded. Have you?

Thx a lot.

Ps: when solved or' or, I'll make a full report on your post.

[jesinwp]

Yes I checked those screenshots, there is "www.domain.com" in the PHP script but during the actual testing some real domain (censored)?

[mtx-z]

Yes domain was hided (censored for sharing it) . I can give you full url by email if you want.
But md5 result and cache files are from real url, not changed.

[jesinwp]

Can you send it using this contact form? Also send me your Nginx virtual host file.

[mtx-z]

Sure. But as you, I'm not using a cache purge location.
I want to be able to do a selective delete url based of the corresponding cache file.

[mtx-z]

Thanks a lot @jesinwp. The PHP script you made work perfectly.

Error was entierly mine: resetting the cache_key further in the config file, so not the same as the builded one...
Thanks a lot :)

This also resolve the issue @nottellyou !

[hpatoio]

@mtx-z great ! Share the code and close the ticket !

[mtx-z]

Here is the PHP code to delete the file cache related to the given URL.

$cache_path = '/etc/nginx/cache/';
$url = parse_url($_POST['url']);
if(!$url)
{
    echo 'Invalid URL entered';
    die();
}
$scheme = $url['scheme'];
$host = $url['host'];
$requesturi = $url['path'];
$hash = md5($scheme.'GET'.$host.$requesturi);
var_dump(unlink($cache_path . substr($hash, -1) . '/' . substr($hash,-3,2) . '/' . $hash));

[nottellyou]

hi, @mtx-z

I tried server times , but failed.

server
{
listen 80;
server_name clear.xxxxxxxxxxxxx.net;
index index.html index.htm index.php default.html default.htm default.php;
root /usr/local/nginx/fastcgi_cache;

add_header request-filename $request_filename;
add_header requestfilename  $document_root$fastcgi_script_name;

    location ~ [^/]\.php(/|$)
    {
            try_files $uri =404;
            fastcgi_pass  unix:/dev/shm/php-cgi.sock;
            fastcgi_index index.php;
            include fastcgi.conf;
    }

}
In the dir /usr/local/nginx/fastcgi_cache, only one php file, but visit clear.xxxxxxxxxxxxx.net can't run php file, other file can run.

Do you know why???

[mtx-z]

Hey @nottellyou

Sorry for the huuge delay.
Your fastcgi_cache folder should not contain .php file, are you sure your cache is working correctly ?

On this screen, there is a capture of my cache folder (along with nginx conf).
Also take a look at the original post here, you can search for "mtxz" in the page.