exim_relay_sender_address consists of exim_relay_hostname, which by default is equal to matrix_server_fqn_matrix, whose default value is matrix.example.com
Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>
Overall the playbook uses the expression "Add the following configuration to your `inventory/host_vars/matrix.DOMAIN/vars.yml` file:" with the heading "Adjusting the playbook configuration" for sections to explain what to be added as variables
Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>
This makes all containers (except mautrix-telegram and
mautrix-whatsapp), start as a non-root user.
We do this, because we don't trust some of the images.
In any case, we'd rather not trust ALL images and avoid giving
`root` access at all. We can't be sure they would drop privileges
or what they might do before they do it.
Because Postfix doesn't support running as non-root,
it had to be replaced by an Exim mail server.
The matrix-nginx-proxy nginx container image is patched up
(by replacing its main configuration) so that it can work as non-root.
It seems like there's no other good image that we can use and that is up-to-date
(https://hub.docker.com/r/nginxinc/nginx-unprivileged is outdated).
Likewise for riot-web (https://hub.docker.com/r/bubuntux/riot-web/),
we patch it up ourselves when starting (replacing the main nginx
configuration).
Ideally, it would be fixed upstream so we can simplify.
Relay hostnames that have MX records are looked up by postfix
and the MX record's payload is used instead.
This special behavior may be undesirable, so we make sure to
point it out.
