Add a setting named force_oauth

app/controllers/admin/dashboard_controller.rb

@@ -36,6 +36,7 @@ module Admin
       @timeline_preview      = Setting.timeline_preview
       @spam_check_enabled    = Setting.spam_check_enabled
       @trends_enabled        = Setting.trends
+      @force_oauth           = Setting.force_oauth
     end
 
     private

app/models/form/admin_settings.rb

@@ -35,6 +35,7 @@ class Form::AdminSettings
     show_domain_blocks
     show_domain_blocks_rationale
     noindex
+    force_oauth
   ).freeze
 
   BOOLEAN_KEYS = %i(
@@ -51,6 +52,7 @@ class Form::AdminSettings
     trends
     trendable_by_default
     noindex
+    force_oauth
   ).freeze
 
   UPLOAD_KEYS = %i(

app/views/admin/dashboard/index.html.haml

@@ -71,6 +71,8 @@
           = feature_hint(link_to(t('admin.dashboard.feature_relay'), admin_relays_path), @relay_enabled)
         %li
           = feature_hint(link_to(t('admin.dashboard.feature_spam_check'), edit_admin_settings_path), @spam_check_enabled)
+        %li
+          = feature_hint(link_to(t('admin.dashboard.force_oauth'), edit_admin_settings_path), @force_oauth)
 
   .dashboard__widgets__versions
     %div

app/views/admin/settings/edit.html.haml

@@ -88,6 +88,9 @@
   .fields-group
     = f.input :spam_check_enabled, as: :boolean, wrapper: :with_label, label: t('admin.settings.spam_check_enabled.title'), hint: t('admin.settings.spam_check_enabled.desc_html')
 
+  .fields-group
+    = f.input :force_oauth, as: :boolean, wrapper: :with_label, label: t('admin.settings.force_oauth.title'), hint: t('admin.settings.force_oauth.desc_html')
+
   %hr.spacer/
 
   .fields-group

config/locales/en.yml

@@ -566,6 +566,9 @@ en:
       spam_check_enabled:
         desc_html: Mastodon can auto-report accounts that send repeated unsolicited messages. There may be false positives.
         title: Anti-spam automation
+      force_oauth:
+        desc_html: If SSO authentication is enabled, Mastodon can completely disable other authentication or registration features.
+        title: Force SSO authentication
       thumbnail:
         desc_html: Used for previews via OpenGraph and API. 1200x630px recommended
         title: Server thumbnail

config/settings.yml

@@ -69,6 +69,7 @@ defaults: &defaults
   spam_check_enabled: true
   show_domain_blocks: 'disabled'
   show_domain_blocks_rationale: 'disabled'
+  force_oauth: false
 
 development:
   <<: *defaults