* Registering a new matrix user
#+begin_src
# Help command
$ docker exec -it matrixdotorg-synapse register_new_matrix_user --help

# Registering a new user
$ docker exec -it matrixdotorg-synapse register_new_matrix_user -u ${USERNAME} -c /data/homserver.yaml
#+end_src

* Access postgresql database
#+begin_src
docker run -it --rm --network postgresql-network postgres psql -h postgresql -U postgres
#+end_src