Connection refused when running mix ecto.setup command, packages installed with asdf - postgresql

Question

I'm trying to follow the GraphQL tutorial.
I'm used asdf to install the erlang, elixir and postgres. I'm using a macbook.
When I get to the step to run mix ecto.setup, I'm getting the following error:
20:44:47.318 [error] GenServer #PID<0.1605.0> terminating
** (DBConnection.ConnectionError) tcp connect (localhost:5432): connection refused - :econnrefused
(db_connection) lib/db_connection/connection.ex:163: DBConnection.Connection.connect/2
(connection) lib/connection.ex:622: Connection.enter_connect/5
(stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3
Last message: nil
State: Postgrex.Protocol
** (Mix) The database for Community.Repo couldn't be created: an exception was raised:
** (DBConnection.ConnectionError) tcp connect (localhost:5432): connection refused - :econnrefused
(db_connection) lib/db_connection/connection.ex:163: DBConnection.Connection.connect/2
(connection) lib/connection.ex:622: Connection.enter_connect/5
(stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3
What it could be?

Answer 1

You have to start postgres, according to the asdf-postgree docs you have to:
pg_ctl start
And in order to run the commands mix ecto.create and mix ecto.setup you have to create a user postgres with the password postgres, and the postgres user must have permissions to both LOGIN and CREATEDB, then you can:
Create a default database:
createdb default
Log to that database, with:
psql -d default
And create the user with the permissions:
# CREATE ROLE postgres LOGIN CREATEDB PASSWORD 'postgres';