FEATURE: add site setting allow_new_registrations which can be used to block all new account registrations

app/assets/javascripts/discourse/controllers/login.js.es6

@@ -37,7 +37,10 @@ export default Discourse.Controller.extend(Discourse.ModalFunctionality, {
   }.property('loggingIn'),
 
   showSignupLink: function() {
-    return !Discourse.SiteSettings.invite_only && !this.get('loggingIn') && this.blank('authenticate');
+    return !Discourse.SiteSettings.invite_only &&
+           Discourse.SiteSettings.allow_new_registrations &&
+           !this.get('loggingIn') &&
+           this.blank('authenticate');
   }.property('loggingIn', 'authenticate'),
 
   showSpinner: function() {

app/controllers/invites_controller.rb

@@ -4,6 +4,7 @@ class InvitesController < ApplicationController
   skip_before_filter :redirect_to_login_if_required
 
   before_filter :ensure_logged_in, only: [:destroy, :create, :check_csv_chunk, :upload_csv_chunk]
+  before_filter :ensure_new_registrations_allowed, only: [:show, :redeem_disposable_invite]
 
   def show
     invite = Invite.find_by(invite_key: params[:id])
@@ -137,4 +138,11 @@ class InvitesController < ApplicationController
     params[:email]
   end
 
+  def ensure_new_registrations_allowed
+    unless SiteSetting.allow_new_registrations
+      flash[:error] = I18n.t('login.new_registrations_disabled')
+      render layout: 'no_js'
+      false
+    end
+  end
 end

app/controllers/users_controller.rb

@@ -146,6 +146,11 @@ class UsersController < ApplicationController
   end
 
   def create
+    unless SiteSetting.allow_new_registrations
+      render json: { success: false, message: I18n.t("login.new_registrations_disabled") }
+      return
+    end
+
     user = User.new(user_params)
 
     authentication = UserAuthenticator.new(user, session)

app/views/invites/show.html.erb

@@ -0,0 +1,7 @@
+<div id='simple-container'>
+  <%if flash[:error]%>
+    <div class='alert alert-error'>
+      <%=flash[:error]%>
+    </div>
+  <%end%>
+</div>

config/locales/server.en.yml

@@ -765,6 +765,7 @@ en:
     sso_overrides_name: "Overrides local name with external site name from SSO payload (WARNING: discrepancies can occur due to normalization of local names)"
 
     enable_local_logins: "Enable local username and password login based accounts. (Note: this must be enabled for invites to work)"
+    allow_new_registrations: "Allow new user registrations. Uncheck this to prevent anyone from creating a new account."
     enable_google_logins: "(deprecated) Enable Google authentication. This is the OpenID method of authentication which Google has deprecated. New installs will NOT work with this. Use Google Oauth2 instead. Existing installs must move to Google Oauth2 by April 20, 2015."
     enable_yahoo_logins: "Enable Yahoo authentication"
 
@@ -1058,6 +1059,7 @@ en:
     something_already_taken: "Something went wrong, perhaps the username or email is already registered. Try the forgot password link."
     omniauth_error: "Sorry, there was an error authorizing your %{strategy} account. Perhaps you did not approve authorization?"
     omniauth_error_unknown: "Something went wrong processing your log in, please try again."
+    new_registrations_disabled: "New account registrations are not allowed at this time."
 
   user:
     username:

config/site_settings.yml

@@ -178,6 +178,9 @@ login:
   enable_local_logins:
     client: true
     default: true
+  allow_new_registrations:
+    client: true
+    default: true
   # The default value of enable_google_logins changed from true to false.
   # See db/migrate/20140521220115_google_openid_default_has_changed.rb
   enable_google_logins:

spec/controllers/invites_controller_spec.rb

@@ -148,6 +148,17 @@ describe InvitesController do
 
     end
 
+    context 'new registrations are disabled' do
+      let(:topic) { Fabricate(:topic) }
+      let(:invite) { topic.invite_by_email(topic.user, "iceking@adventuretime.ooo") }
+      before { SiteSetting.stubs(:allow_new_registrations).returns(false) }
+
+      it "doesn't redeem the invite" do
+        Invite.any_instance.stubs(:redeem).never
+        get :show, id: invite.invite_key
+      end
+    end
+
   end
 
   context '.create_disposable_invite' do

spec/controllers/users_controller_spec.rb

@@ -269,6 +269,7 @@ describe UsersController do
 
   describe '#create' do
     before do
+      SiteSetting.stubs(:allow_new_registrations).returns(true)
       @user = Fabricate.build(:user)
       @user.password = "strongpassword"
       DiscourseHub.stubs(:register_username).returns([true, nil])
@@ -291,6 +292,14 @@ describe UsersController do
         expect(response.status).to eq(500)
       end
 
+      it 'returns an error when new registrations are disabled' do
+        SiteSetting.stubs(:allow_new_registrations).returns(false)
+        post_user
+        json = JSON.parse(response.body)
+        json['success'].should be_false
+        json['message'].should be_present
+      end
+
       it 'creates a user correctly' do
         Jobs.expects(:enqueue).with(:user_email, has_entries(type: :signup))
         User.any_instance.expects(:enqueue_welcome_message).with('welcome_user').never
@@ -355,6 +364,14 @@ describe UsersController do
         expect(JSON.parse(response.body)['active']).to be_true
       end
 
+      it 'returns 500 status when new registrations are disabled' do
+        SiteSetting.stubs(:allow_new_registrations).returns(false)
+        post_user
+        json = JSON.parse(response.body)
+        json['success'].should be_false
+        json['message'].should be_present
+      end
+
       context 'authentication records for' do
 
         before do