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Create a database for your Rails application

In this guide, we will show you how to create a database for your Ruby on Rails application using Deploio. You can see more information on databases here.

Should you wish to migrate an already existing database from elsewhere, you can view this section in the documentation here, or read this blog which guides you through migrating a Rails project from Heroku.

Create the database​

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To ensure the database resource gets allocated to the correct project, you should switch to the correct project context:

nctl auth set-project my-project

Alternatively, you can specify the project name with the -p, --project flag in the following commands.

To create a postgres database server for your Rails application, you can use the nctl create command like this:

nctl create postgres {NAME} \
  --postgres-version=15 \
  --machine-type=nine-db-s \
  --allowed-cidrs="203.0.113.1/32,..." \
  --ssh-keys-file=my-key.pub

Further details on the flags can be found in the manual by running nctl create postgres --help.

You can now access the server using the fully-qualified domain name (FQDN) and generated user and password. You can find this information as follows:

$ nctl get postgres {NAME}
PROJECT       NAME      FQDN                                   LOCATION     MACHINE TYPE
my-project    {NAME}    {NAME}.1234567.postgres.nineapis.ch    nine-cz41    nine-db-s

$ nctl get postgres {NAME} --print-user
dbadmin

$ nctl get postgres {NAME} --print-password
...password...

To create a database on the server, create an interactive shell in your web application with:

nctl exec app {APP_NAME}

In that shell, run the following command to create the database:

createdb -U dbadmin -h {FQDN} my-database

You will be prompted to define a password.

You can verify that this database was created by logging into the server using psql -U dbadmin -h {FQDN} -d postgres and then running the command \l to list the databases on the server.

Configure Your Rails Application​

To connect your Rails application to the database, you need to set the DATABASE_URL environment variable. You can retrieve the value of this environment variable by running:

nctl get postgres {NAME} --print-connection-string
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The connection string will look something like this: postgres://dbadmin:password@{FQDN}. Append the database name to the end of this string to create the full connection string.

To configure the DATABASE_URL environment variable in your application, run:

nctl update app {APP_NAME} \
--env="DATABASE_URL=$(nctl get postgres {NAME} --print-connection-string)/my-database"

Where my-database is the name of the database you created.

Troubleshooting​

If you encounter any issues when connecting to the database, check that your IP address was correctly added to the allowed CIDRs. You can do this by running:

nctl get postgres {NAME} -o yaml

and then search for the allowedCIDRs field. To add your current IP address, you could use the following command:

nctl update postgres {NAME} --allowed-cidrs "$(curl -s ipinfo.io/ip)/32"

Also, ensure that your current client version is compatible with the database version. You can find the currently used version in the YAML output of nctl get by searching for the version field.

Further Steps​

Check Database Configuration​

Rails should automatically use the DATABASE_URL environment variable to connect to the database. However, you may need to adjust the database.yml file in your Rails application to ensure that it is using the correct database and that the current configuration is appropriate.

Run Migrations​

You can now run the migrations on your Rails application to create the tables in the database. This can be done through the deploio.yaml file by specifying a deploy job or by manually running the migrations:

nctl exec app {APP_NAME} rails db:migrate

If you did not get any errors during the migration, you should now have a healthy connection to your database and be able to interact with it through your Rails application.

Next Steps​

Do you need a Redis-compatible key value store for your application (e.g. for running Sidekiq)? Proceed to the next step.

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