By default, this playbook would set up a PostgreSQL database server on your machine, running in a Docker container. If that's alright, you can skip this.
If you'd like to use an external PostgreSQL server that you manage, you can edit your configuration file (inventory/host_vars/matrix.<your-domain>/vars.yml).
It should be something like this:
matrix_postgres_enabled: false
# Rewire Synapse to use your external Postgres server
matrix_synapse_database_host: "your-postgres-server-hostname"
matrix_synapse_database_user: "your-postgres-server-username"
matrix_synapse_database_password: "your-postgres-server-password"
matrix_synapse_database_database: "your-postgres-server-database-name"The database (as specified in matrix_synapse_database_database) must exist and be accessible with the given credentials.
It must be empty or contain a valid Synapse database. If empty, Synapse would populate it the first time it runs.
Note: the external server that you specify in matrix_synapse_database_host must be accessible from within the matrix-synapse Docker container (and possibly other containers too). This means that it either needs to be a publicly accessible hostname or that it's a hostname on the same Docker network where all containers installed by this playbook run (a network called matrix by default). Using a local PostgreSQL instance on the host (running on the same machine, but not in a container) is not possible.
The connection to your external Postgres server will not be SSL encrypted, as we don't support that yet.