I was working on Ubuntu 16 and faced some real problem to setup postgresql and connect it with my rails application.
Here is what I have done.
Ubuntu’s default repository by default contains Postges package. We can easily install postgrs in command line using apt. Moreover, we will install posgresql-contrib which will add additional features.
$ sudo apt-get update $ sudo apt-get install postgresql postgresql-contrib
This is an important concept while working with postgres. Postgres uses roles for authentication.
If there is a role in present in postgres, the ubuntu user with the same name will be able to signin as that role to postgres.
While I installed postgres from command line, it automatically created a user named postgres and linked it to the postgres role of the database.
Now we can switch over to postgres user by writing the following line in the terminal –
sudo -i -u postgres
Now we can access the postgresql command line by typing
It will show a command line with postgres=#
Exit the postgres command line with –
Creating a new role for the ruby on rails application
At first, make sure the postgres user is logged in. If not, use the mentioned command to log in with postgres user in the terminal.
Now create the user with the following command –
It will ask the username. I did put it as ‘kimran’.
It will ask will it be a superuser (y/n). I did put it as ‘y’.
Create database for the new user
By default, postgres will assume there is a database named same as the user name.
For example, If the kimran user tries to connect to postgres, it will automatically try to connect with a database named ‘kimran’.
Let’s do it by the following command –
Create ubuntu user according to the new role
We have created the role named ‘kimran’ and a database named ‘kimran’.
Now, we will have to create an ubuntu user with the same name i.e. ‘kimran’.
sudo adduser kimran
Now switch to that new user and connect to the new poostgres prompt.
sudo -i -u kimran psql
Add a password for the kimran role. Otherwise you will not be able to connect to the rials application. Do it by the following command –
\password kimran Enter new password:
Now check your connection status –
It will show something like this –
You are connected to database "kimran" as user "kimran" via socket in "/var/run/postgresql" at port "5432".
Set up databse.yml in your Ruby on Rails App
Now we will have to modify database.yml file according to the information we got from the ‘conninfo’ command in prompt.
default: &default adapter: postgresql encoding: unicode pool: 5 development: <<: *default database: test_project_development username: kimran password: password socket: /var/run/postgresql host: localhost port: 5432 test: <<: *default database: test_project_test username: khaled password: password socket: /var/run/postgresql host: localhost port: 5432 production: <<: *default database: test_project username: kimran password: password socket: /var/run/postgresql host: localhost port: 5432
Create the project Database
Now we can just create the database from tarminal. Go to the root of the project.
Now run the rake command to create the database
It should now create the database in postgresql.
Now run the migration files –
Well, now you are ready to go with Postgres for your rails application. Do you think it can be done in a better way? Please comment if you think so.