This is a runtime layer that is intended to be built upon by other charm layers. It provides Apache2 and modphp5, and manages sites based on an apache.yaml defined in the charm layer that uses this.

In your charm layer's composer.yaml, you will need to include this layer, e.g.:

includes: ['layers:apache-php']

Then, you will need to include an apache.yaml file which can specify additional packages to install, and one or more sites to install and manage. Each site definition should include an install_from section whose keys are arguments to install_remote and should at a minimum include a source value. It can also include an options value, to be used for the Options directive, and a server_name value, to be used for the ServerName directive and which can reference config options via {config["<key>"]} interpolation. An example apache.yaml might look like:

packages:
    - 'php5-mysql'
    - 'php5-gd'
sites:
    vanilla:
        server_name: '{config["hostname"]}'
        options: 'Indexes FollowSymLinks MultiViews'
        install_from:
            source: https://github.com/vanillaforums/Garden/archive/Vanilla_2.0.18.8.tar.gz
            checksum: acf61a7ffca9359c1e1d721777182e51637be59744925935291801ccc8e8fd55
            hash_type: sha256

Your site will be installed in to /var/www/<site> where <site> is the name of your site entry (vanilla in the example above).

Finally, your charm layer will need to interact with this layer via reactive states. This layer will set the apache.available state once your apache.yaml has been processed and all sites installed, at which point your charm layer should perform any additional setup (such as creating site config files, opening the appropriate ports, etc) and then set the apache.start state.