By default, this playbook would set up a PostgreSQL database server on your machine, running in a Docker container. If that's okay, you can skip this document.
**Note**: using **an external Postgres server is currently [not very seamless](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1682#issuecomment-1061461683) when it comes to enabling various other playbook services** - you will need to create a new database/credentials for each service and to point each service to its corresponding database using custom `vars.yml` configuration. **For the best experience with the playbook, stick to using the integrated Postgres server**.
If you'd like to use an external Postgres server that you manage, add the following configuration to your `inventory/host_vars/matrix.DOMAIN/vars.yml` file (adapt to your needs):
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](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/89).