DEV: Convert email_in_min_trust to groups (#24515)

This change converts the `email_in_min_trust` site setting to
`email_in_allowed_groups`.

See: https://meta.discourse.org/t/283408

- Hides the old setting
- Adds the new site setting
- Add a deprecation warning
- Updates to use the new setting
- Adds a migration to fill in the new setting if the old setting was
  changed
- Adds an entry to the site_setting.keywords section
- Updates tests to account for the new change

After a couple of months we will remove the
`email_in_min_trust` setting entirely.

Internal ref: /t/115696

config/locales/server.en.yml

@@ -2140,6 +2140,8 @@ en:
     log_mail_processing_failures: "Log all email processing failures to <a href='%{base_path}/logs' target='_blank'>/logs</a>"
     email_in: "Allow users to post new topics via email. After enabling this setting, you will be able to configure incoming email addresses for groups and categories."
     email_in_min_trust: "The minimum trust level a user needs to have to be allowed to post new topics via email."
+    email_in_allowed_groups: "Groups that are allowed to post new topics via email."
+
     email_in_authserv_id: "The identifier of the service doing authentication checks on incoming emails. See <a href='https://meta.discourse.org/t/134358'>https://meta.discourse.org/t/134358</a> for instructions on how to configure this."
     email_in_spam_header: "The email header to detect spam."
 
@@ -2547,6 +2549,7 @@ en:
       shared_drafts_allowed_groups: "shared_drafts_min_trust_level"
       approve_unless_allowed_groups: "approve_unless_trust_level"
       approve_new_topics_unless_allowed_groups: "approve_new_topics_unless_trust_level"
+      email_in_allowed_groups: "email_in_min_trust"
 
     placeholder:
       discourse_connect_provider_secrets:

config/site_settings.yml

@@ -1254,6 +1254,13 @@ email:
   email_in_min_trust:
     default: 2
     enum: "TrustLevelSetting"
+    hidden: true
+  email_in_allowed_groups:
+    default: 12
+    type: group_list
+    allow_any: false
+    refresh: true
+    validator: "AtLeastOneGroupValidator"
   email_in_authserv_id:
     default: ""
   email_in_spam_header:

db/migrate/20231122212122_fill_email_in_allowed_groups_based_on_deprecated_settings.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class FillEmailInAllowedGroupsBasedOnDeprecatedSettings < ActiveRecord::Migration[7.0]
+  def up
+    email_in_min_trust_raw =
+      DB.query_single(
+        "SELECT value FROM site_settings WHERE name = 'email_in_min_trust' LIMIT 1",
+      ).first
+
+    # Default for old setting is TL0, we only need to do anything if it's been changed in the DB.
+    if email_in_min_trust_raw.present?
+      # Matches Group::AUTO_GROUPS to the trust levels.
+      email_in_allowed_groups = "1#{email_in_min_trust_raw}"
+
+      # Data_type 20 is group_list
+      DB.exec(
+        "INSERT INTO site_settings(name, value, data_type, created_at, updated_at)
+        VALUES('email_in_allowed_groups', :setting, '20', NOW(), NOW())",
+        setting: email_in_allowed_groups,
+      )
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end

lib/email/receiver.rb

@@ -859,7 +859,8 @@ module Email
 
         user ||= stage_from_user
 
-        if !user.has_trust_level?(SiteSetting.email_in_min_trust) && !sent_to_mailinglist_mirror?
+        if user.groups.any? && !user.in_any_groups?(SiteSetting.email_in_allowed_groups_map) &&
+             !sent_to_mailinglist_mirror?
           raise InsufficientTrustLevelError
         end
 
@@ -1067,7 +1068,9 @@ module Email
         )
       elsif destination.is_a?(Category)
         return false if user.staged? && !destination.email_in_allow_strangers
-        return false if !user.has_trust_level?(SiteSetting.email_in_min_trust)
+        if user.groups.any? && !user.in_any_groups?(SiteSetting.email_in_allowed_groups_map)
+          return false
+        end
 
         topic_user = embedded_user&.call || user
         create_topic(

lib/site_settings/deprecated_settings.rb

@@ -18,6 +18,7 @@ module SiteSettings::DeprecatedSettings
       false,
       "3.3",
     ],
+    ["email_in_min_trust", "email_in_allowed_groups", false, "3.3"],
   ]
 
   def setup_deprecated_methods

spec/lib/email/receiver_spec.rb

@@ -948,6 +948,7 @@ RSpec.describe Email::Receiver do
             Fabricate.build(:secondary_email, email: "discourse@bar.com"),
             Fabricate.build(:secondary_email, email: "someone@else.com"),
           ],
+          refresh_auto_groups: true,
         )
 
       user2 =
@@ -958,6 +959,7 @@ RSpec.describe Email::Receiver do
             Fabricate.build(:secondary_email, email: "team@bar.com"),
             Fabricate.build(:secondary_email, email: "wat@bar.com"),
           ],
+          refresh_auto_groups: true,
         )
 
       expect { process(:cc) }.to change(Topic, :count)
@@ -1534,8 +1536,8 @@ RSpec.describe Email::Receiver do
     end
 
     it "raises an InsufficientTrustLevelError when user's trust level isn't enough" do
-      Fabricate(:user, email: "existing@bar.com", trust_level: 3)
+      Fabricate(:user, email: "existing@bar.com", trust_level: 3, refresh_auto_groups: true)
-      SiteSetting.email_in_min_trust = 4
+      SiteSetting.email_in_allowed_groups = Group::AUTO_GROUPS[:trust_level_4]
       expect { process(:existing_user) }.to raise_error(
         Email::Receiver::InsufficientTrustLevelError,
       )
@@ -1584,7 +1586,12 @@ RSpec.describe Email::Receiver do
     it "creates visible topic for ham" do
       SiteSetting.email_in_spam_header = "none"
 
-      Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
+      Fabricate(
+        :user,
+        email: "existing@bar.com",
+        trust_level: SiteSetting.email_in_min_trust,
+        refresh_auto_groups: true,
+      )
       expect { process(:existing_user) }.to change { Topic.count }.by(1) # Topic created
 
       topic = Topic.last
@@ -1600,7 +1607,12 @@ RSpec.describe Email::Receiver do
       SiteSetting.email_in_spam_header = "X-Spam-Flag"
 
       user =
-        Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
+        Fabricate(
+          :user,
+          email: "existing@bar.com",
+          trust_level: SiteSetting.email_in_min_trust,
+          refresh_auto_groups: true,
+        )
       expect { process(:spam_x_spam_flag) }.to change { ReviewableQueuedPost.count }.by(1)
       expect(user.reload.silenced?).to be(true)
     end
@@ -1609,7 +1621,12 @@ RSpec.describe Email::Receiver do
       SiteSetting.email_in_spam_header = "X-Spam-Status"
 
       user =
-        Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
+        Fabricate(
+          :user,
+          email: "existing@bar.com",
+          trust_level: SiteSetting.email_in_min_trust,
+          refresh_auto_groups: true,
+        )
       expect { process(:spam_x_spam_status) }.to change { ReviewableQueuedPost.count }.by(1)
       expect(user.reload.silenced?).to be(true)
     end
@@ -1618,7 +1635,12 @@ RSpec.describe Email::Receiver do
       SiteSetting.email_in_spam_header = "X-SES-Spam-Verdict"
 
       user =
-        Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
+        Fabricate(
+          :user,
+          email: "existing@bar.com",
+          trust_level: SiteSetting.email_in_min_trust,
+          refresh_auto_groups: true,
+        )
       expect { process(:spam_x_ses_spam_verdict) }.to change { ReviewableQueuedPost.count }.by(1)
       expect(user.reload.silenced?).to be(true)
     end
@@ -1627,7 +1649,12 @@ RSpec.describe Email::Receiver do
       SiteSetting.email_in_authserv_id = "example.com"
 
       user =
-        Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
+        Fabricate(
+          :user,
+          email: "existing@bar.com",
+          trust_level: SiteSetting.email_in_min_trust,
+          refresh_auto_groups: true,
+        )
       expect { process(:dmarc_fail) }.to change { ReviewableQueuedPost.count }.by(1)
       expect(user.reload.silenced?).to be(false)
     end
@@ -1635,7 +1662,12 @@ RSpec.describe Email::Receiver do
     it "adds the 'elided' part of the original message when always_show_trimmed_content is enabled" do
       SiteSetting.always_show_trimmed_content = true
 
-      Fabricate(:user, email: "existing@bar.com", trust_level: SiteSetting.email_in_min_trust)
+      Fabricate(
+        :user,
+        email: "existing@bar.com",
+        trust_level: SiteSetting.email_in_min_trust,
+        refresh_auto_groups: true,
+      )
       expect { process(:forwarded_email_to_category) }.to change { Topic.count }.by(1) # Topic created
 
       new_post, = Post.last
@@ -1698,13 +1730,13 @@ RSpec.describe Email::Receiver do
     end
 
     it "lets an email in from a high-TL user" do
-      Fabricate(:user, email: "tl4@bar.com", trust_level: TrustLevel[4])
+      Fabricate(:user, email: "tl4@bar.com", trust_level: TrustLevel[4], refresh_auto_groups: true)
       expect { process(:tl4_user) }.to change(Topic, :count)
     end
 
     it "fails on email from a low-TL user" do
-      SiteSetting.email_in_min_trust = 4
+      SiteSetting.email_in_allowed_groups = Group::AUTO_GROUPS[:trust_level_4]
-      Fabricate(:user, email: "tl3@bar.com", trust_level: TrustLevel[3])
+      Fabricate(:user, email: "tl3@bar.com", trust_level: TrustLevel[3], refresh_auto_groups: true)
       expect { process(:tl3_user) }.to raise_error(Email::Receiver::InsufficientTrustLevelError)
     end
   end