Cache control by Cacholong
“Cache control by Cacholong” plugin automates purging of Nginx FastCGI cache on your Nginx server(s). It is a backend plugin that is able to:
- Purge Nginx FastCGI cache.
- Purge cache automatically, manually, with WordPress cronjobs and WP-CLI.
- Purge caches on one or more servers (See hosts.json section for more details).
- Use commandline (WP-CLI) to purge caches or reset to factory settings.
- Allow purging of other cached items (see Settings > Cache control).
- Inform user of purge status.
- Support for single site and network sites
- Support for WP-CLI
- Support for WPML (including language negotiation type domain)
When will it purge?
This plugin will work with default and custom post types. It will purge on a save, regular update, quick edit update, slug change, delete and undelete. The user is informed with one or more messages. There are a few caveats:
- When a user is using the Gutenberg editor, purge messages will not be displayed.
- When the user uses “Quick edit” and “Updates” the post, no messages will be displayed, because there’s no page refresh. Those messages will be shown on the next request.
It is possible to purge with WordPress cronjobs. Adjust the ‘Cronjob settings’ to perform a daily purge of caches.
You can also purge items manually. Go to the WordPress dashboard and navigate to:
- Settings > Cache control > purge single item
- Settings > Cache control > purge all caches
- Admin Toolbar > purge all caches
Settings
- File with hosts (JSON): File with information about one or more hosts for this WordPress installation. See hosts.json section for more details.
- Purge settings default post types: Select one or more options when purging a default post type. Possible to purge post url (default), home page, all connected WordPress categories or all caches.
- Purge settings default custom type(s): Select one or more options when purging a custom post type. Possible to purge post url (default), home page, all connected WordPress categories or all caches.
Cronjob Settings
- Cronjob purging: Enable or disable cronjob purging.
- Cronjob time of each day: Enter HH:MM in 24 hour notation for cronjob time of day. Will fallback to 00:00 when wrong format is given.
- Purge caches Select caches to purge on given cronjob time.
hosts.json
Hosts.json is a JSON file with information about one or more servers for this WordPress installation. Remember that this file must contain information about all servers, including the one with this plugin. Default path is: wp-content/uploads/cacholong-cache-control/hosts.json.
Here is an example of a hosts.json file:
{"servers":
[
{"name": "server1", "ip": "127.0.0.1", "fastcgi": false},
{"name": "server2", "ip": "127.0.0.2", "fastcgi": true},
]
}
Each line contains information about one server. Parameters:
-
name (string) Name of host, something to identify this server.
-
ip (string) IP address of server or full url. Format: scheme://host:port/path
-
fastcgi (bool) Server user Nginx FastCGI (true) or not (false)
When there is no hosts.json or the path is invalid, this plugin assumes the following:
{"servers":
[
{"name": "localhost", "ip": "127.0.0.1", "fastcgi": true}
]
}
How does it work
“Cache control by Cacholong” empties partial or full cache for Nginx FastCGI cache. WordPress HTTP API is used to make (post) request to specific urls to trigger purges. Based on the http header responses this plugin determines if a purge is successful or not. The user is informed with messages, which are loaded after a purge and page refresh.
There are several settings to tweak purging, see Settings > Cache control.
WP-CLI
There are several commands available for the commandline with wp-cli. Commands generate text output which can be suppressed with –quiet. When an error occurs, text will always be displayed.
WP-CLI exit codes
Exit codes are 0 (no errors) or 1 (generic error).
WP-CLI examples
Purge command with all arguments:
wp cacholong_cc purge [--cache=<cache>] [--ips=<ips>]
Purge Nginx FastCGI:
wp cacholong_cc purge --cache=fastcgi
Purge all caches:
wp cacholong_cc purge --cache=all
wp cacholong_cc purge
Purge all caches for ip address 127.0.0.1 and 127.0.0.2:
wp cacholong_cc purge --ips=127.0.0.1,127.0.0.2
Factory reset options for given site_id or current blog if no site_id is given:
wp cacholong_cc factory_reset [--site_id=site_id]
Debug
Plugin will log basic purge information when WP_DEBUG is true (can be set in wp-config.php). Logs information in file wp-content/cacholong-cache-control.log. Plugin will log wp_remote_request details when CACHOLONG_CACHE_DEBUG_HTTP_API_REQUEST is true (can be set in wp-config.php). Logs information in file wp-content/cacholong-cache-control.log.