Add public blocks to /about/blocks (#11298)

* Add automatic blocklist display in /about/blocks

Inspired by https://github.com/Gargron/mastodon.social-misc

* Add admin option to set who can see instance blocks

* Normalize locales files

* Rename “Sandbox” to “Silence” for consistency

* Disable /about/blocks when in whitelist mode

* Optionally display rationale for domain blocks

* Only display domain blocks that have user-facing limitations, and order them

* Redesign table of blocked domains to better handle long domain names and rationales

* Change domain blocks ordering now that rationales aren't displayed right away

* Only show explanation for block severities actually in use

* Reword instance block explanations and add disclaimer for public fetch mode

app/controllers/about_controller.rb

@@ -3,10 +3,12 @@
 class AboutController < ApplicationController
   layout 'public'
 
-  before_action :require_open_federation!, only: [:show, :more]
+  before_action :require_open_federation!, only: [:show, :more, :blocks]
+  before_action :check_blocklist_enabled, only: [:blocks]
+  before_action :authenticate_user!, only: [:blocks], if: :blocklist_account_required?
   before_action :set_body_classes, only: :show
   before_action :set_instance_presenter
-  before_action :set_expires_in
+  before_action :set_expires_in, only: [:show, :more, :terms]
 
   skip_before_action :require_functional!, only: [:more, :terms]
 
@@ -18,12 +20,40 @@ class AboutController < ApplicationController
 
   def terms; end
 
+  def blocks
+    @show_rationale = Setting.show_domain_blocks_rationale == 'all'
+    @show_rationale |= Setting.show_domain_blocks_rationale == 'users' && !current_user.nil? && current_user.functional?
+    @blocks = DomainBlock.with_user_facing_limitations.order('(CASE severity WHEN 0 THEN 1 WHEN 1 THEN 2 WHEN 2 THEN 0 END), reject_media, domain').to_a
+  end
+
   private
 
   def require_open_federation!
     not_found if whitelist_mode?
   end
 
+  def check_blocklist_enabled
+    not_found if Setting.show_domain_blocks == 'disabled'
+  end
+
+  def blocklist_account_required?
+    Setting.show_domain_blocks == 'users'
+  end
+
+  def block_severity_text(block)
+    if block.severity == 'suspend'
+      I18n.t('domain_blocks.suspension')
+    else
+      limitations = []
+      limitations << I18n.t('domain_blocks.media_block') if block.reject_media?
+      limitations << I18n.t('domain_blocks.silence') if block.severity == 'silence'
+      limitations.join(', ')
+    end
+  end
+
+  helper_method :block_severity_text
+  helper_method :public_fetch_mode?
+
   def new_user
     User.new.tap do |user|
       user.build_account

app/javascript/packs/public.js

@@ -141,6 +141,15 @@ function main() {
     return false;
   });
 
+  delegate(document, '.blocks-table button.icon-button', 'click', function(e) {
+    e.preventDefault();
+
+    const classList = this.firstElementChild.classList;
+    classList.toggle('fa-chevron-down');
+    classList.toggle('fa-chevron-up');
+    this.parentElement.parentElement.nextElementSibling.classList.toggle('hidden');
+  });
+
   delegate(document, '.modal-button', 'click', e => {
     e.preventDefault();
 

app/javascript/styles/mastodon/tables.scss

@@ -241,3 +241,70 @@ a.table-action-link {
     }
   }
 }
+
+.blocks-table {
+  width: 100%;
+  max-width: 100%;
+  border-spacing: 0;
+  border-collapse: collapse;
+  table-layout: fixed;
+  border: 1px solid darken($ui-base-color, 8%);
+
+  thead {
+    border: 1px solid darken($ui-base-color, 8%);
+    background: darken($ui-base-color, 4%);
+    font-weight: 500;
+
+    th.severity-column {
+      width: 120px;
+    }
+
+    th.button-column {
+      width: 23px;
+    }
+  }
+
+  tbody > tr {
+    border: 1px solid darken($ui-base-color, 8%);
+    border-bottom: 0;
+    background: darken($ui-base-color, 4%);
+
+    &:hover {
+      background: darken($ui-base-color, 2%);
+    }
+
+    &.even {
+      background: $ui-base-color;
+
+      &:hover {
+        background: lighten($ui-base-color, 2%);
+      }
+    }
+
+    &.rationale {
+      background: lighten($ui-base-color, 4%);
+      border-top: 0;
+
+      &:hover {
+        background: lighten($ui-base-color, 6%);
+      }
+
+      &.hidden {
+        display: none;
+      }
+    }
+
+    td:first-child {
+      overflow: hidden;
+      text-overflow: ellipsis;
+    }
+  }
+
+  th,
+  td {
+    padding: 8px;
+    line-height: 18px;
+    vertical-align: top;
+    text-align: left;
+  }
+}

app/models/domain_block.rb

@@ -25,6 +25,7 @@ class DomainBlock < ApplicationRecord
   delegate :count, to: :accounts, prefix: true
 
   scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
+  scope :with_user_facing_limitations, -> { where(severity: [:silence, :suspend]).or(where(reject_media: true)) }
 
   class << self
     def suspend?(domain)

app/models/form/admin_settings.rb

@@ -30,6 +30,8 @@ class Form::AdminSettings
     mascot
     spam_check_enabled
     trends
+    show_domain_blocks
+    show_domain_blocks_rationale
   ).freeze
 
   BOOLEAN_KEYS = %i(
@@ -60,6 +62,8 @@ class Form::AdminSettings
   validates :site_contact_email, :site_contact_username, presence: true
   validates :site_contact_username, existing_username: true
   validates :bootstrap_timeline_accounts, existing_username: { multiple: true }
+  validates :show_domain_blocks, inclusion: { in: %w(disabled users all) }
+  validates :show_domain_blocks_rationale, inclusion: { in: %w(disabled users all) }
 
   def initialize(_attributes = {})
     super

app/views/about/blocks.html.haml

@@ -0,0 +1,48 @@
+- content_for :page_title do
+  = t('domain_blocks.title', instance: site_hostname)
+
+.grid
+  .column-0
+    .box-widget.rich-formatting
+      %h2= t('domain_blocks.blocked_domains')
+      %p= t('domain_blocks.description', instance: site_hostname)
+      .table-wrapper
+        %table.blocks-table
+          %thead
+            %tr
+              %th= t('domain_blocks.domain')
+              %th.severity-column= t('domain_blocks.severity')
+              - if @show_rationale
+                %th.button-column
+          %tbody
+            - if @blocks.empty?
+              %tr
+                %td{ colspan: @show_rationale ? 3 : 2 }= t('domain_blocks.no_domain_blocks')
+            - else
+              - @blocks.each_with_index do |block, i|
+                %tr{ class: i % 2 == 0 ? 'even': nil }
+                  %td{ title: block.domain }= block.domain
+                  %td= block_severity_text(block)
+                  - if @show_rationale
+                    %td
+                      - if block.public_comment.present?
+                        %button.icon-button{ title: t('domain_blocks.show_rationale'), 'aria-label' => t('domain_blocks.show_rationale') }
+                          = fa_icon 'chevron-down fw', 'aria-hidden' => true
+                - if @show_rationale
+                  - if block.public_comment.present?
+                    %tr.rationale.hidden
+                      %td{ colspan: 3 }= block.public_comment.presence
+      %h2= t('domain_blocks.severity_legend.title')
+      - if @blocks.any? { |block| block.reject_media? }
+        %h3= t('domain_blocks.media_block')
+        %p= t('domain_blocks.severity_legend.media_block')
+      - if @blocks.any? { |block| block.severity == 'silence' }
+        %h3= t('domain_blocks.silence')
+        %p= t('domain_blocks.severity_legend.silence')
+      - if @blocks.any? { |block| block.severity == 'suspend' }
+        %h3= t('domain_blocks.suspension')
+        %p= t('domain_blocks.severity_legend.suspension')
+        - if public_fetch_mode?
+          %p= t('domain_blocks.severity_legend.suspension_disclaimer')
+  .column-1
+    = render 'application/sidebar'

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

@@ -79,6 +79,12 @@
   .fields-group
     = f.input :min_invite_role, wrapper: :with_label, collection: %i(disabled user moderator admin), label: t('admin.settings.registrations.min_invite_role.title'), label_method: lambda { |role| role == :disabled ? t('admin.settings.registrations.min_invite_role.disabled') : t("admin.accounts.roles.#{role}") }, include_blank: false, collection_wrapper_tag: 'ul', item_wrapper_tag: 'li'
 
+  .fields-row
+    .fields-row__column.fields-row__column-6.fields-group
+      = f.input :show_domain_blocks, wrapper: :with_label, collection: %i(disabled users all), label: t('admin.settings.domain_blocks.title'), label_method: lambda { |value| t("admin.settings.domain_blocks.#{value}") }, include_blank: false, collection_wrapper_tag: 'ul', item_wrapper_tag: 'li'
+    .fields-row__column.fields-row__column-6.fields-group
+      = f.input :show_domain_blocks_rationale, wrapper: :with_label, collection: %i(disabled users all), label: t('admin.settings.domain_blocks_rationale.title'), label_method: lambda { |value| t("admin.settings.domain_blocks.#{value}") }, include_blank: false, collection_wrapper_tag: 'ul', item_wrapper_tag: 'li'
+
   .fields-group
     = f.input :closed_registrations_message, as: :text, wrapper: :with_block_label, label: t('admin.settings.registrations.closed_message.title'), hint: t('admin.settings.registrations.closed_message.desc_html'), input_html: { rows: 8 }
     = f.input :site_extended_description, wrapper: :with_block_label, as: :text, label: t('admin.settings.site_description_extended.title'), hint: t('admin.settings.site_description_extended.desc_html'), input_html: { rows: 8 } unless whitelist_mode?

config/locales/en.yml

@@ -423,6 +423,13 @@ en:
       custom_css:
         desc_html: Modify the look with CSS loaded on every page
         title: Custom CSS
+      domain_blocks:
+        all: To everyone
+        disabled: To no one
+        title: Show domain blocks
+        users: To logged-in local users
+      domain_blocks_rationale:
+        title: Show rationale
       hero:
         desc_html: Displayed on the frontpage. At least 600x100px recommended. When not set, falls back to server thumbnail
         title: Hero image
@@ -630,6 +637,23 @@ en:
     people:
       one: "%{count} person"
       other: "%{count} people"
+  domain_blocks:
+    blocked_domains: List of limited and blocked domains
+    description: This is the list of servers that %{instance} limits or reject federation with.
+    domain: Domain
+    media_block: Media block
+    no_domain_blocks: "(No domain blocks)"
+    severity: Severity
+    severity_legend:
+      media_block: Media files coming from the server are neither fetched, stored, or displayed to the user.
+      silence: Accounts from silenced servers can be found, followed and interacted with, but their toots will not appear in the public timelines, and notifications from them will not reach local users who are not following them.
+      suspension: No content from suspended servers is stored or displayed, nor is any content sent to them. Interactions from suspended servers are ignored.
+      suspension_disclaimer: Suspended servers may occasionally retrieve public content from this server.
+      title: Severities
+    show_rationale: Show rationale
+    silence: Silence
+    suspension: Suspension
+    title: "%{instance} List of blocked instances"
   domain_validator:
     invalid_domain: is not a valid domain name
   errors:

config/routes.rb

@@ -425,6 +425,7 @@ Rails.application.routes.draw do
 
   get '/about',        to: 'about#show'
   get '/about/more',   to: 'about#more'
+  get '/about/blocks', to: 'about#blocks'
   get '/terms',        to: 'about#terms'
 
   root 'home#index'

config/settings.yml

@@ -64,6 +64,8 @@ defaults: &defaults
   peers_api_enabled: true
   show_known_fediverse_at_about_page: true
   spam_check_enabled: true
+  show_domain_blocks: 'disabled'
+  show_domain_blocks_rationale: 'disabled'
 
 development:
   <<: *defaults