Read users from known LDAP providers and create them in Gitlab

ldap-users-prepare.rb

# Read users from known LDAP providers and create them in Gitlab
# Tested on Gitlab v18.1

# Create users on behalf of this user
creator = User.find_by(username: 'root')
# Add user to default organization
organization_id = Organizations::Organization.find_by(name: 'Default').id

Gitlab::Auth::Ldap::Config.providers.each do |provider|
  Gitlab::Auth::Ldap::Adapter.open(provider) do |adapter|
    uid_field = adapter.config.uid
    ldap_users = adapter.users(uid_field, '*')

    ldap_users.each do |ldap_user|
      extern_uid = ldap_user.dn
      email = ldap_user.email.first.strip.downcase
      username = ldap_user.username.strip.downcase
      name = ldap_user.name

      next unless email && username

      # Skip if user already exists
      next if User.find_by_email(email) || User.find_by_username(username)

      puts "Creating user: #{username} (#{email}, #{extern_uid})..."

      new_user_srv = Users::CreateService.new(creator,
        username: username,
        email: email,
        name: name || username,
        organization_id: organization_id,
        skip_confirmation: true,
        force_random_password: true,
        password_automatically_set: true,
        extern_uid: extern_uid,
        provider: provider,
      )
      new_user = new_user_srv.execute

      if new_user.error?
        puts "Failed to create user #{username}: #{new_user.errors.full_messages.join(', ')}"
      else
        puts "Successfully created user: #{username}"
      end
    end
  end
end