Remove email restrictions feature flag

Removes the feature flag and introduces email restrictions via
regular expressions as a setting for GitLab instance
administrators.

app/models/user.rb

@@ -1786,7 +1786,6 @@ class User < ApplicationRecord
   end
 
   def check_email_restrictions
-    return unless Feature.enabled?(:email_restrictions)
     return unless Gitlab::CurrentSettings.email_restrictions_enabled?
 
     restrictions = Gitlab::CurrentSettings.email_restrictions

app/views/admin/application_settings/_signup.html.haml

@@ -49,20 +49,19 @@
       = f.label :domain_blacklist, 'Blacklisted domains for sign-ups', class: 'label-bold'
       = f.text_area :domain_blacklist_raw, placeholder: 'domain.com', class: 'form-control', rows: 8
       .form-text.text-muted Users with e-mail addresses that match these domain(s) will NOT be able to sign-up. Wildcards allowed. Use separate lines for multiple entries. Ex: domain.com, *.domain.com
-    - if Feature.enabled?(:email_restrictions)
-      .form-group
-        = f.label :email_restrictions_enabled, _('Email restrictions'), class: 'label-bold'
-        .form-check
-          = f.check_box :email_restrictions_enabled, class: 'form-check-input'
-          = f.label :email_restrictions_enabled, class: 'form-check-label' do
-            = _('Enable email restrictions for sign ups')
-      .form-group
-        = f.label :email_restrictions, _('Email restrictions for sign-ups'), class: 'label-bold'
-        = f.text_area :email_restrictions, class: 'form-control', rows: 4
-        .form-text.text-muted
-        - supported_syntax_link_url = 'https://github.com/google/re2/wiki/Syntax'
-        - supported_syntax_link_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: supported_syntax_link_url }
-        = _('Restricts sign-ups for email addresses that match the given regex. See the %{supported_syntax_link_start}supported syntax%{supported_syntax_link_end} for more information.').html_safe % { supported_syntax_link_start: supported_syntax_link_start, supported_syntax_link_end: '</a>'.html_safe }
+    .form-group
+      = f.label :email_restrictions_enabled, _('Email restrictions'), class: 'label-bold'
+      .form-check
+        = f.check_box :email_restrictions_enabled, class: 'form-check-input'
+        = f.label :email_restrictions_enabled, class: 'form-check-label' do
+          = _('Enable email restrictions for sign ups')
+    .form-group
+      = f.label :email_restrictions, _('Email restrictions for sign-ups'), class: 'label-bold'
+      = f.text_area :email_restrictions, class: 'form-control', rows: 4
+      .form-text.text-muted
+      - supported_syntax_link_url = 'https://github.com/google/re2/wiki/Syntax'
+      - supported_syntax_link_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: supported_syntax_link_url }
+      = _('Restricts sign-ups for email addresses that match the given regex. See the %{supported_syntax_link_start}supported syntax%{supported_syntax_link_end} for more information.').html_safe % { supported_syntax_link_start: supported_syntax_link_start, supported_syntax_link_end: '</a>'.html_safe }
 
     .form-group
       = f.label :after_sign_up_text, class: 'label-bold'

changelogs/unreleased/nicolasdular-remove-email-restrictions-ff.yml

+---
+title: Add option to restrict emails that match a configured regular expression
+merge_request: 30548
+author:
+type: added

spec/models/user_spec.rb

@@ -538,18 +538,6 @@ describe User, :do_not_mock_admin_mode do
             expect(user).to be_valid
           end
 
-          context 'when feature flag is turned off' do
-            before do
-              stub_feature_flags(email_restrictions: false)
-            end
-
-            it 'does accept the email address' do
-              user = build(:user, email: 'info+1@test.com')
-
-              expect(user).to be_valid
-            end
-          end
-
           context 'when created_by_id is set' do
             it 'does accept the email address' do
               user = build(:user, email: 'info+1@test.com', created_by_id: 1)