Wordpress Cache-Enabler Plugin Missing "dont cache query strings" in nginx Cache Enabler section(?)

Hello,

Not sure at all what's going on and/or if it's a real bug so take it with a grain of salt ;-)

Very recently I have weird behaviors on a lead generation form that's dynamically populating incoming Query String parameters into the form fields through PHP (it's a gravity form) : basically sometimes after the cache is deleted by the centminmod CRON job, the query parameters won't be saved in the fields anymore.

Gravity form supports says that this page should not be cached... (so how did it work for so long??)

After investigating a bit, I found that KeyCDN Cache Enabler support page states an Nginx directive to avoid caching of pages with query strings:

WordPress Cache Enabler Plugin - KeyCDN Support

Code:

server {

    set $cache_uri $request_uri;

    # bypass cache if POST requests or URLs with a query string
    if ($request_method = POST) {
        set $cache_uri 'nullcache';
    }
    if ($query_string != "") {
        set $cache_uri 'nullcache';
    }
...

After looking into centmindmod Vhost configuration, I can't find the equivalent of this "if ($query_string != "") {set $cache_uri 'nullcache';}".

Is this normal or a bug or a choice(I which case maybe I should have configured that query string not cached in another way) ?

Thanks a lot,

• CentOS Version: i.e. CentOS 6 64bit
• Centmin Mod Version Installed: 123.09beta01
• Nginx Version Installed: i.e. 1.11.13
• PHP Version Installed: i.e. 5.6.30
• MariaDB MySQL Version Installed: no clue
• When was last time updated Centmin Mod code base ? : no clue
• Persistent Config: Do you have any persistent config file options set in /etc/centminmod/custom_config.inc ? No

---

 

Here we go: main config file:

Code:

server {

  server_name mydomain.com www.mydomain.com;

# ngx_pagespeed & ngx_pagespeed handler
#include /usr/local/nginx/conf/pagespeed.conf;
#include /usr/local/nginx/conf/pagespeedhandler.conf;
#include /usr/local/nginx/conf/pagespeedstatslog.conf;

  #add_header X-Frame-Options SAMEORIGIN;
  #add_header X-Xss-Protection "1; mode=block" always;
  #add_header X-Content-Type-Options "nosniff" always;

  # limit_conn limit_per_ip 16;
  # ssi  on;

  access_log /home/nginx/domains/mydomain.com/log/access.log main_ext buffer=256k$
  error_log /home/nginx/domains/mydomain.com/log/error.log;

  include /usr/local/nginx/conf/autoprotect/mydomain.com/autoprotect-travaillerav$
  root /home/nginx/domains/mydomain.com/public;
  # uncomment cloudflare.conf include if using cloudflare for
  # server and/or vhost site
  #include /usr/local/nginx/conf/cloudflare.conf;
  include /usr/local/nginx/conf/503include-main.conf;

  include /usr/local/nginx/conf/wpincludes/mydomain.com/wpcacheenabler_travailler$
  #include /usr/local/nginx/conf/wpincludes/mydomain.com/wpsupercache_travaillera$
  # https://community.centminmod.com/posts/18828/
  #include /usr/local/nginx/conf/wpincludes/mydomain.com/rediscache_travaillerave$

  location / {
  include /usr/local/nginx/conf/503include-only.conf;


  # Enables directory listings when index file not found
  #autoindex  on;
  # for wordpress super cache plugin
  #try_files /wp-content/cache/supercache/$http_host/$cache_uri/index.html $uri $uri/ /index.php$

  # for wp cache enabler plugin
  try_files $cache_enabler_uri $uri $uri/ $custom_subdir/index.php?$args;

  # Wordpress Permalinks
  #try_files $uri $uri/ /index.php?q=$uri&$args;

  # Nginx level redis Wordpress
  # https://community.centminmod.com/posts/18828/
  #try_files $uri $uri/ /index.php?$args;

  }
location ~* /(wp-login\.php) {
    limit_req zone=xwplogin burst=1 nodelay;
    #limit_conn xwpconlimit 30;
    #auth_basic "Private";
    #auth_basic_user_file /home/nginx/domains/mydomain.com/htpasswd_wplogin;
    include /usr/local/nginx/conf/php-wpsc.conf;
    # https://community.centminmod.com/posts/18828/
    #include /usr/local/nginx/conf/php-rediscache.conf;
}

location ~* /(xmlrpc\.php) {
    limit_req zone=xwprpc burst=45 nodelay;
    #limit_conn xwpconlimit 30;
    include /usr/local/nginx/conf/php-wpsc.conf;
    # https://community.centminmod.com/posts/18828/
    #include /usr/local/nginx/conf/php-rediscache.conf;
}
  include /usr/local/nginx/conf/wpincludes/mydomain.com/wpsecure_travailleravecle$
  include /usr/local/nginx/conf/php-wpsc.conf;
  # https://community.centminmod.com/posts/18828/
  #include /usr/local/nginx/conf/php-rediscache.conf;
  include /usr/local/nginx/conf/staticfiles.conf;
  include /usr/local/nginx/conf/drop.conf;
  #include /usr/local/nginx/conf/errorpage.conf;
  include /usr/local/nginx/conf/vts_server.conf;
}

And the cache enabler one:

Code:

   # Block nginx-help log from public viewing
    location ~* /wp-content/uploads/nginx-helper/ { deny all; }

    set $cache_uri $request_uri;

    # exclude mobile devices from redis caching
    if ($cmwpcache_device = mobile) { set $cache_uri 'nullcache'; }

    # bypass cache if POST requests or URLs with a query string
    if ($request_method = POST) {
        set $cache_uri 'nullcache';
    }
    if ($query_string != "") {
        set $cache_uri 'nullcache';
    }

    # bypass cache if URLs containing the following strings
    if ($request_uri ~* "(\?add-to-cart=|/cart/|/my-account/|/checkout/|/shop/checkout/|/store/c$
        set $cache_uri 'nullcache';
    }

    # bypass cache if the cookies containing the following strings
    if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_logged_in|edd_$
        set $cache_uri 'nullcache';
    }

    # custom sub directory e.g. /blog
    set $custom_subdir '';

    # default html file
    set $cache_enabler_uri '${custom_subdir}/wp-content/cache/cache-enabler/${http_host}${cache_$
    # webp html file
    if ($http_accept ~* "image/webp") {
        set $cache_enabler_uri '${custom_subdir}/wp-content/cache/cache-enabler/${http_host}${ca$
    }

I didn't know there a specific config file for Cache Enabler and indeed: the code to bypass cache when there is a query string is there as expected.

So I guess I'm not looking in the right direction to find the source of this problem... I find it pretty odd that the problem occurs after the CRON deletes the cache, I also suspected a problem with Autoptimize but I'm still waiting for this to be confirmed. Since the developer said it was handled by PHP, I doubt Autoptimize to be the culprit but we'll see.

If you have any other idea on what could cause this, I'm interested ;-)

Thanks for the help anyway, it doesn't look like it's the nginx config!

Cheers,

 

Thanks, yeah I'll try the exclude cache by post ID too ;-)

 

OK so in case someone has the issue someday : despite nginx config saying that URL query parameters shouldn't be cached, somehow GravityForm dynamic field population based on URL query parameters IS GETTING CACHED... so basically the form gets populated with always the same parameter no matter was is passed in the URL.

Now the good new: excluding by POST IDS inside the Cache Enabler plugin did solve the problem.

I'm not exactly sure what's going on but at least I found a working configuration.