database.yml

<% 
  branch = `git rev-parse --abbrev-ref HEAD`.strip rescue ENV.fetch("RAILS_DATABASE_SUFFIX", "master")
  branch = branch.underscore.gsub(/[\.\/\-]/, '_')
%>

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS", 5) %>
  host: <%= ENV.fetch("RAILS_DATABASE_HOST", "127.0.0.1") %>
  port: <%= ENV.fetch("RAILS_DATABASE_PORT", 5432) %>
  username: <%= ENV.fetch("RAILS_DATABASE_USERNAME", "postgres") %>
  password: <%= ENV.fetch("RAILS_DATABASE_PASSWORD", "") %>
  timeout: 5000
  prepared_statements: true # never set to false or be vulnerable to SQLi
  statement_limit: 1000

development:
  <<: *default
  database: <%= ENV.fetch("RAILS_DATABASE", "rails") %>_development_<%= branch %>

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: <%= ENV.fetch("RAILS_DATABASE", "rails") + "_test" %>

production:
  <<: *default
  database: <%= ENV.fetch("RAILS_DATABASE", "rails") %>
  host: /cloudsql/<%= ENV.fetch("RAILS_DATABASE_INSTANCE_NAME", "") %>
  password: <%= Rails.application.credentials.dig(:database, :password) %>