Remove SQLite production warning but leave production config disabled

There are valid use cases for running SQLite in production, however it must be done
with care, so instead of a warning most users won't see anyway, it's preferable to
leave the configuration commented out to force them to think about having the database
on a persistent volume etc.

Co-Authored-By: Jacopo Beschi <[email protected]>

.github/workflows/rails-new-docker.yml

@@ -33,6 +33,7 @@ jobs:
         podman run --name $APP_NAME \
         -v $(pwd):$(pwd) \
         -e SECRET_KEY_BASE_DUMMY=1 \
+        -e DATABASE_URL=sqlite3:storage/production.sqlite3 \
         -p 3000:3000 $APP_NAME &
     - name: Test container
       run: ruby -r ./.github/workflows/scripts/test-container.rb

activerecord/CHANGELOG.md

@@ -1,3 +1,12 @@
+*   Remove warning message when running SQLite in production, but leave it unconfigured
+
+    There are valid use cases for running SQLite in production, however it must be done
+    with care, so instead of a warning most users won't see anyway, it's preferable to
+    leave the configuration commented out to force them to think about having the database
+    on a persistent volume etc.
+
+    *Jacopo Beschi*, *Jean Boussier*
+
 *   Add support for generated columns in SQLite3 adapter
 
     Generated columns (both stored and dynamic) are supported since version 3.31.0 of SQLite.

activerecord/lib/active_record/railtie.rb

@@ -31,7 +31,6 @@ class Railtie < Rails::Railtie # :nodoc:
     config.active_record.check_schema_cache_dump_version = true
     config.active_record.maintain_test_schema = true
     config.active_record.has_many_inversing = false
-    config.active_record.sqlite3_production_warning = true
     config.active_record.query_log_tags_enabled = false
     config.active_record.query_log_tags = [ :application ]
     config.active_record.query_log_tags_format = :legacy
@@ -232,13 +231,13 @@ class Railtie < Rails::Railtie # :nodoc:
       end
     end
 
-    SQLITE3_PRODUCTION_WARN = "You are running SQLite in production, this is generally not recommended."\
-      " You can disable this warning by setting \"config.active_record.sqlite3_production_warning=false\"."
-    initializer "active_record.sqlite3_production_warning" do
-      if config.active_record.sqlite3_production_warning && Rails.env.production?
-        ActiveSupport.on_load(:active_record_sqlite3adapter) do
-          Rails.logger.warn(SQLITE3_PRODUCTION_WARN)
-        end
+    initializer "active_record.sqlite3_deprecated_warning" do
+      if config.active_record.key?(:sqlite3_production_warning)
+        config.active_record.delete(:sqlite3_production_warning)
+        ActiveRecord.deprecator.warn <<~MSG.squish
+          The `config.active_record.sqlite3_production_warning` configuration no longer has any effect
+          and can be safely removed.
+        MSG
       end
     end
 
@@ -278,7 +277,6 @@ class Railtie < Rails::Railtie # :nodoc:
           :query_log_tags,
           :query_log_tags_format,
           :cache_query_log_tags,
-          :sqlite3_production_warning,
           :sqlite3_adapter_strict_strings_by_default,
           :check_schema_cache_dump_version,
           :use_schema_cache_dump

railties/lib/rails/generators/rails/app/templates/config/databases/sqlite3.yml.tt

@@ -20,6 +20,13 @@ test:
   <<: *default
   database: storage/test.sqlite3
 
+
+# SQLite3 write its data on the local filesystem, as such it requires
+# persistent disks. If you are deploying to a managed service, you should
+# make sure it provides disk persistence, as many don't.
+#
+# Similarly, if you deploy your application as a Docker container, you must
+# ensure the database is located in a persisted volume.
 production:
   <<: *default
-  database: storage/production.sqlite3
+# database: path/to/persistent/storage/production.sqlite3

railties/test/application/configuration_test.rb

@@ -31,17 +31,6 @@ def self.safe_list_sanitizer
   end
 end
 
-class MyLogRecorder < Logger
-  def initialize
-    @io = StringIO.new
-    super(@io)
-  end
-
-  def recording
-    @io.string
-  end
-end
-
 module ApplicationTests
   class ConfigurationTest < ActiveSupport::TestCase
     include ActiveSupport::Testing::Isolation
@@ -79,7 +68,6 @@ def switch_development_hosts_to(*hosts)
     def setup
       build_app
       suppress_default_config
-      suppress_sqlite3_warning
     end
 
     def teardown
@@ -96,14 +84,6 @@ def restore_default_config
       FileUtils.mv("#{app_path}/config/__environments__", "#{app_path}/config/environments")
     end
 
-    def suppress_sqlite3_warning
-      add_to_config "config.active_record.sqlite3_production_warning = false"
-    end
-
-    def restore_sqlite3_warning
-      remove_from_config ".*config.active_record.sqlite3_production_warning.*\n"
-    end
-
     test "Rails.env does not set the RAILS_ENV environment variable which would leak out into rake tasks" do
       require "rails"
 
@@ -4061,57 +4041,6 @@ class Post < ActiveRecord::Base
       assert_equal false, Rails.application.env_config["action_dispatch.log_rescued_responses"]
     end
 
-    test "logs a warning when running SQLite3 in production" do
-      restore_sqlite3_warning
-      app_file "config/initializers/active_record.rb", <<~RUBY
-        ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
-      RUBY
-      add_to_config "config.logger = MyLogRecorder.new"
-
-      app "production"
-
-      assert_match(/You are running SQLite in production, this is generally not recommended/, Rails.logger.recording)
-    end
-
-    test "doesn't log a warning when running SQLite3 in production and sqlite3_production_warning=false" do
-      app_file "config/initializers/active_record.rb", <<~RUBY
-        ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
-      RUBY
-      add_to_config "config.logger = MyLogRecorder.new"
-
-      app "production"
-
-      assert_no_match(/You are running SQLite in production, this is generally not recommended/, Rails.logger.recording)
-    end
-
-    test "doesn't log a warning when running MySQL in production" do
-      restore_sqlite3_warning
-      original_configurations = ActiveRecord::Base.configurations
-      ActiveRecord::Base.configurations = { production: { db1: { adapter: "mysql2" } } }
-      app_file "config/initializers/active_record.rb", <<~RUBY
-        ActiveRecord::Base.establish_connection(adapter: "mysql2")
-      RUBY
-      add_to_config "config.logger = MyLogRecorder.new"
-
-      app "production"
-
-      assert_no_match(/You are running SQLite in production, this is generally not recommended/, Rails.logger.recording)
-    ensure
-      ActiveRecord::Base.configurations = original_configurations
-    end
-
-    test "doesn't log a warning when running SQLite3 in development" do
-      restore_sqlite3_warning
-      app_file "config/initializers/active_record.rb", <<~RUBY
-        ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
-      RUBY
-      add_to_config "config.logger = MyLogRecorder.new"
-
-      app "development"
-
-      assert_no_match(/You are running SQLite in production, this is generally not recommended/, Rails.logger.recording)
-    end
-
     test "app starts with LocalCache middleware" do
       app "development"
 

railties/test/application/loading_test.rb

@@ -418,7 +418,6 @@ def test_initialize_can_be_called_at_any_time
   end
 
   test "active record query cache hooks are installed before first request in production" do
-    add_to_config "config.active_record.sqlite3_production_warning = false"
     app_file "app/controllers/omg_controller.rb", <<-RUBY
       begin
         class OmgController < ActionController::Metal

railties/test/application/query_logs_test.rb

@@ -10,7 +10,6 @@ class QueryLogsTest < ActiveSupport::TestCase
 
     def setup
       build_app(multi_db: true)
-      add_to_config "config.active_record.sqlite3_production_warning = false"
       rails("generate", "scaffold", "Pet", "name:string", "--database=animals")
       app_file "app/models/user.rb", <<-RUBY
         class User < ActiveRecord::Base