moebooru/db/migrate/077_create_server_keys.rb

require "digest/sha1"

class CreateServerKeys < ActiveRecord::Migration[5.1]
  def self.up
    create_table :server_keys do |t|
      t.column :name, :string, null: false
      t.column :value, :text
    end

    add_index :server_keys, :name, unique: true

    session_secret_key = CONFIG["session_secret_key"] || Digest::SHA1.hexdigest(rand(10**32))
    user_password_salt = CONFIG["password_salt"] || Digest::SHA1.hexdigest(rand(10**32))

    execute "insert into server_keys (name, value) values ('session_secret_key', '#{session_secret_key}')"
    execute "insert into server_keys (name, value) values ('user_password_salt', '#{user_password_salt}')"
  end

  def self.down
    drop_table :server_keys
  end
end