Use storage/ instead of db/ for sqlite3 db files (rails#46699)

* Use storage/ instead of db/ for sqlite3 db files

db/ should be for configuration only, not data. This will make it easier to mount a single volume into a container for testing, development, and even sqlite3 in production.

Author: dhh

actionmailbox/test/dummy/config/database.yml

@@ -11,15 +11,15 @@ default: &default
 
 development:
   <<: *default
-  database: db/development.sqlite3
+  database: storage/development.sqlite3
 
 # Warning: The database defined as "test" will be erased and
 # re-generated from your development database when you run "rake".
 # Do not set this db to the same as development or production.
 test:
   <<: *default
-  database: db/test.sqlite3
+  database: storage/test.sqlite3
 
 production:
   <<: *default
-  database: db/production.sqlite3
+  database: storage/production.sqlite3

actiontext/test/dummy/config/database.yml

@@ -11,15 +11,15 @@ default: &default
 
 development:
   <<: *default
-  database: db/development.sqlite3
+  database: storage/development.sqlite3
 
 # Warning: The database defined as "test" will be erased and
 # re-generated from your development database when you run "rake".
 # Do not set this db to the same as development or production.
 test:
   <<: *default
-  database: db/test.sqlite3
+  database: storage/test.sqlite3
 
 production:
   <<: *default
-  database: db/production.sqlite3
+  database: storage/production.sqlite3

activerecord/CHANGELOG.md

@@ -697,7 +697,7 @@
     ```yaml
     development:
         <<: *default
-        database: db/development.sqlite3
+        database: storage/development.sqlite3
         foreign_keys: false
     ```
 

activerecord/lib/active_record/connection_handling.rb

@@ -272,7 +272,7 @@ def primary_class? # :nodoc:
     #
     #  ActiveRecord::Base.connection_db_config
     #    #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbded10 @env_name="development",
-    #      @name="primary", @config={pool: 5, timeout: 5000, database: "db/development.sqlite3", adapter: "sqlite3"}>
+    #      @name="primary", @config={pool: 5, timeout: 5000, database: "storage/development.sqlite3", adapter: "sqlite3"}>
     #
     # Use only for reading.
     def connection_db_config

activerecord/lib/active_record/core.rb

@@ -53,19 +53,19 @@ def self.destroy_association_async_job
       #
       #   development:
       #     adapter: sqlite3
-      #     database: db/development.sqlite3
+      #     database: storage/development.sqlite3
       #
       #   production:
       #     adapter: sqlite3
-      #     database: db/production.sqlite3
+      #     database: storage/production.sqlite3
       #
       # ...would result in ActiveRecord::Base.configurations to look like this:
       #
       #   #<ActiveRecord::DatabaseConfigurations:0x00007fd1acbdf800 @configurations=[
       #     #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbded10 @env_name="development",
-      #       @name="primary", @config={adapter: "sqlite3", database: "db/development.sqlite3"}>,
+      #       @name="primary", @config={adapter: "sqlite3", database: "storage/development.sqlite3"}>,
       #     #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbdea90 @env_name="production",
-      #       @name="primary", @config={adapter: "sqlite3", database: "db/production.sqlite3"}>
+      #       @name="primary", @config={adapter: "sqlite3", database: "storage/production.sqlite3"}>
       #   ]>
       def self.configurations=(config)
         @@configurations = ActiveRecord::DatabaseConfigurations.new(config)

activerecord/test/cases/connection_adapters/connection_handler_test.rb

@@ -204,13 +204,13 @@ def test_symbolized_configurations_assignment
           development: {
             primary: {
               adapter: "sqlite3",
-              database: "test/db/development.sqlite3",
+              database: "test/storage/development.sqlite3",
             },
           },
           test: {
             primary: {
               adapter: "sqlite3",
-              database: "test/db/test.sqlite3",
+              database: "test/storage/test.sqlite3",
             },
           },
         }

activerecord/test/cases/schema_dumper_test.rb

@@ -418,7 +418,7 @@ def test_do_not_dump_foreign_keys_when_bypassed_by_config
         ActiveRecord::Base.establish_connection(
           {
             adapter: "sqlite3",
-            database: "test/db/test.sqlite3",
+            database: "test/storage/test.sqlite3",
             foreign_keys: false,
           }
         )

guides/source/configuring.md

@@ -2772,7 +2772,7 @@ Here's the section of the default configuration file (`config/database.yml`) wit
 ```yaml
 development:
   adapter: sqlite3
-  database: db/development.sqlite3
+  database: storage/development.sqlite3
   pool: 5
   timeout: 5000
 ```
@@ -2844,7 +2844,7 @@ If you choose to use SQLite3 and are using JRuby, your `config/database.yml` wil
 ```yaml
 development:
   adapter: jdbcsqlite3
-  database: db/development.sqlite3
+  database: storage/development.sqlite3
 ```
 
 #### Configuring a MySQL or MariaDB Database for JRuby Platform
@@ -3198,7 +3198,7 @@ Active Record database connections are managed by `ActiveRecord::ConnectionAdapt
 ```ruby
 development:
   adapter: sqlite3
-  database: db/development.sqlite3
+  database: storage/development.sqlite3
   pool: 5
   timeout: 5000
 ```

railties/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   Always generate the storage/ directory with rails new to ensure there's a stable place to 
+    put permanent files, and a single mount point for containers to map. Then default sqlite3 databases
+    to live there instead of db/, which is only meant for configuration, not data.
+
+    *DHH*
+
 *   Rails console now disables `IRB`'s autocompletion feature in production by default.
 
     Setting `IRB_USE_AUTOCOMPLETE=true` can override this default.

railties/lib/rails/generators/rails/app/app_generator.rb

@@ -406,7 +406,7 @@ def create_system_test_files
       end
 
       def create_storage_files
-        build(:storage) unless skip_active_storage?
+        build(:storage)
       end
 
       def delete_app_assets_if_api_option