Manually

Using encrypted passwords

Add the bcrypt gem to Your Gemfile

gem 'bcrypt'

and run bundler

bundle install

Create the User model

rails g model user name:string password_digest:string

Add has_secure_password to the model

class User < ApplicationRecord
  has_secure_password
end

Edit config

Edit the config/initializers/rails_admin.rb file and add the authentication.

  config.authenticate_with do
    authenticate_or_request_with_http_basic('Login required') do |username, password|
      user = User.where(name:username).first
      user.authenticate(password) if user
    end
  end

Using unencrypted passwords 💣

👉Saving plain text passwords could get you in trouble with GDPR, you have been warned 👈

In config/initializers/rails_admin.rb, you can add the following lines of code:

config.authenticate_with do
  authenticate_or_request_with_http_basic('Login required') do |username, password|
    user = User.where(email: username, password: password, admin: true).first
    user
  end
end

This will call your User object from the database and check if it exists, If yes, it will login else it won't.