htcachemon

htcachemon is a tool to view statistics about entries in an Apache mod_disk_cache cache. Users can also manually purge URLs from the cache. It uses the Apache htcacheclean tool in the back-end to accomplish this.

Security

Both the server component and the web interface should be secured from unauthorised access. Exactly what measures you take to achieve that is left as an exercise for the reader.

Things to note

Expiry times

The expiry time reported by htcacheclean appears to be based solely on the Expires header value of the cache entry, and, for example, ignores any Cache-Control values that may also be present. This means that entries may be marked "stale" in the UI even if Apache will still use the cached entry - say, because of a Cache-Control value that overrides the Expires header.

Installation

API Server

You will need to have node.js and the Apache htcacheclean utility installed and, of course, an Apache server and a mod_cache_disk cache.

1. Clone the git repository at git@github.com:stainsby/htcachemon.git.
2. cd into your cloned repository and run npm install to install the NPM packages that the server component depends on.
3. Edit <repo>/config.js to suit your system. Common items to change will be cacheDir, uid and http.port.
4. Run the server with the user corresponding to uid in the config.js file. The serve.sh script provides an example of this.

Web interface

The web interface is just a set of static files to create an AngularJS single page application. All dependencies are provided (or come from CDNs).

1. Adjust <repo>/ui/config.js to suit your system. You will likely need to change the API endpoint.
2. Configure your web server to serve the files in <repo>/ui.

If you are only testing, you can use the devserve.sh script to serve the web interface. You will need to have http-server installed - for example, via npm -g install http-server.