This is no beginner stuff! Every time I have to do a fresh install of Postgresql and make it work with Ruby on Rails. It is a pain in the ass. I made up my mind that this is going to be the last time I will have trouble doing this. So here we go with every minute details.
System Specification
- Ubuntu 20.04
- Postgres 12+
NOTE: This is the version of Ubuntu Linux I’m testing it with. Ubuntu is my primary OS. This should work on other Ubuntu versions without any change.
Installing Postgres
sudo apt-get install postgresql postgresql-contrib libpq-dev
Two ways to access Postgres from Rails
1. As the system user when no username and password is provided
# create a username with the same name as linux user with no password
sudo -u postgres psql
create role <linux_user_name> with createdb login password '';
2. Create a dedicated user for the application with password
# start Postgres interactive shell
sudo -i -u postgres psql
create role <app_name> with createdb login password '<app_name>';
Update the database.yml file with username and password in the default section or both test and development records
username: <app_name>
password: <app_name>