Configuring the Ansible playbook

To configure the playbook, you need to have done the following things:

You can then follow these steps inside the playbook directory:

create a directory to hold your configuration (mkdir inventory/host_vars/matrix.<your-domain>)
copy the sample configuration file (cp examples/host-vars.yml inventory/host_vars/matrix.<your-domain>/vars.yml)
edit the configuration file (inventory/host_vars/matrix.<your-domain>/vars.yml) to your liking. You may also take a look at the various roles/ROLE_NAME_HERE/defaults/main.yml files and see if there's something you'd like to copy over and override in your vars.yml configuration file.
copy the sample inventory hosts file (cp examples/hosts inventory/hosts)
edit the inventory hosts file (inventory/hosts) to your liking

For a basic Matrix installation, that's all you need. For a more custom setup, see the Other configuration options below.

When you're done with all the configuration you'd like to do, continue with Installing.

Other configuration options

Setting up the Dimension Integration Manager (optional, but recommended; after installing)

Configuring Synapse (optional)
Configuring Riot-web (optional)
Storing Matrix media files on Amazon S3 (optional)
Using an external PostgreSQL server (optional)
Adjusting mxisd Identity Server configuration (optional)
Adjusting SSL certificate retrieval (optional, advanced)
Serving your base domain using this playbook's nginx server (optional)
Configure Nginx (optional, advanced) (optional, advanced)
Using your own webserver, instead of this playbook's nginx proxy (optional, advanced)
Adjusting TURN server configuration (optional, advanced)

Setting up the REST authentication password provider module (optional, advanced)
Setting up the Shared Secret Auth password provider module (optional, advanced)
Setting up the LDAP password provider module (optional, advanced)
Setting up Synapse Simple Antispam (optional, advanced)
Setting up Matrix Corporal (optional, advanced)